PATENT AGENTS EXAMINATION PAPER B. Wednesday - April 26, :00 am to 1:00 pm INSTRUCTIONS

Transcription

1 PATENT AGENTS EXAMINATION PAPER B Wednesday - April 26, :00 am to 1:00 pm INSTRUCTIONS You must place your assigned number on each examination paper, answer book(s) and envelope. No further identification may be used on any material submitted. At the conclusion of the examination period, place the examination paper and answer book(s) in the envelope and give the sealed envelope to the supervisor. The only aids that you are permitted are the Patent Act and Patent Rules and any English, French and/or bilingual dictionaries. Salutations, signatures and other formalities of correspondence are not required in your answers; substance is what is important. Give reasons for your choices and alternatives. Skeleton and outline answers will be considered if they appear on the right hand pages. Identify your answers by question number. Write legibly in ink, double spaced, on the right side of the answer booklet. Markers are not obliged to consider anything that is written on the left hand pages. You may use the left hand pages for your notes and drafts. You may refer to, incorporate and use portions of the examination paper in your answers. Total marks available in this paper: 100

2 Page 1 of 34 PATENT AGENT EXAMINATION PAPER B 2006 Questions B1 to B10 All questions to be answered. B 1. Your client Bob Banks of Kleenr Pools calls in a panic. His lead employee Tom Steels has left the company. Without seeking your advice, Bob wrote to Tom to remind him of his obligations under his employment agreement to protect Kleenr Pools trade secrets and to remind him of the Canadian patent 2 XXX 123 Kleenr Pools holds and on which Tom and Bob were co-inventors. But the reason Bob is so upset is that Tom has replied, copying his new employer Can Clean Pools, that he did not consider the 2 XXX 123 patent valid in view of his new employer s two patents US 4,761,848 and US 4,208,752 and because he got the idea for the 123 patent from a device he saw before Tom and Bob worked on their own cleaning device. Tom also revealed that he had later found a Japanese Abstract showing the device he had seen. Unfortunately Tom did not provide any further details. Your client couriers you the two patents ( 848 and 752) of Can Clean and Japanese abstract ( 101 ) from Tom Steels. Review the 2 XXX 123 patent of Kleenr Pools to make a preliminary determination of

3 Page 2 of 34 how its validity is affected by the above fact situation. Also consider and discuss any further investigation needed in order to perform a thorough validity analysis. 70 Marks are awarded for an analysis of the invention; construction of the claims analysis of the prior art; validity assessment of the claims including application of the relevant case law; and a discussion of other issues that need further investigation.

4 CP 123 Page 3 of 34 CA 2, xxx,123 Filed 1990/09/14 Issued 1992/08/25 Swimming pool cleaner Abstract A swimming pool cleaner comprising a forwardly inclined body having a flow passage therethrough, an inlet foot having a water inlet foot being attached to the body and connected to the flow passage and when in use, is proximate to a surface to be cleaned, a flexible disc surrounding the water inlet and rotatably connected to the inlet foot and having a peripheral edge, and a stop for preventing upward flexing of the peripheral edge beyond a predetermined amount located forward of the body and substantially above and inward of the peripheral edge.

5 CP 123 Page 4 of 34 FIELD OF THE INVENTION This invention relates to swimming pool cleaners of the well known type which comprise an inlet foot having a water inlet proximate, in use, a surface to be cleaned, a flexible disc surrounding the water inlet to assist in holding the foot against the surface to be cleaned, an inclined or transverse flow passage through a body associated with the foot, and means for repeatedly interrupting the flow through the passage in use. In use the repeated interruption of an induced flow of water through the pool cleaner to the conventional filter plant for a swimming pool causes the pool cleaner to move randomly over the surface being cleaned. BACKGROUND TO THE INVENTION Pool cleaners of the type referred to have become well known in many countries of the world and one such cleaner is sold under the trade mark "Baracuda". The description of the invention below is directed to a pool cleaner of this type but it is to be understood that it can be made suitable for use with other pool cleaners using a flexible disc and interuption of induced flow through the cleaner to promote movement thereof over a surface to be cleaned. A pool cleaner of the type referred to moves, in use, in step-wise manner automatically and in random fashion over submerged surfaces to be cleaned and traverses from horizontal surfaces to vertical surfaces and the reverse. A problem with this type of pool cleaner is, however, the necessity to balance it so that it will remain in an appropriate orientation to the surface being cleaned with the inlet parallel and proximate to surface to be cleaned. This usually requires one side of the pool cleaner to be weighted and the other side to be provided with a float. Some cleaners include a further movable weight to give directional movement to the cleaner during use.

6 CP 123 Page 5 of 34 These factors all increase the weight of the machine and result in a pool cleaner of nonstreamlined configuration, both of which result in increased effort being required to move the cleaner over the surfaces to be cleaned. The effect of the disc on the pool cleaner movement is also such that the disc seriously resists and hinders the movement of the cleaner from horizontal to vertical surfaces and can cause damage where the swimming pool has a liner of vinyl sheet material. It is the object of the present invention to provide a swimming pool cleaner construction which will at least reduce the disadvantages above referred to. In the description which follows orientation and directions will relate to the swimming pool cleaner where operatively located for use on a surface to be cleaned. SUMMARY OF THE INVENTION According to this invention there is provided a swimminig pool cleaner comprising an inlet foot having a water inlet proximate, in use, to a surface to be cleaned, a flexible disc surrounding the water inlet to assist in holding the foot against the surface to be cleaned, an inclined or transverse flow passage through a body, associated with the foot and a means for repeatedly interrupting the flow through the passage in use. The body and the flow passage therethrough is inclined forward relative to the inlet foot, and the cleaner has a stop located forward of the body a short distance above and inward of the periphery of the flexible disc. Further features of the invention provide for the stop to include a weight; for the stop to be located on a support member supported from the body; for the support member to be removably mounted on the body and to have a bumper extending upwardly therefrom, and for the axis of the flow passage to extend at about 45 degrees to the surface to be cleaned in the operative position.

7 CP 123 Page 6 of 34 The invention also provides for a float to be located above the trailing end of the body and for the float to be located at approximately two thirds of the height of the body above the flexible disc in the instance where the pool cleaner has a body similar to that of the "Baracuda" brand pool cleaner. Such a float is preferably located in a retainer therefor, part of which is integrally moulded with the body and the trailing section of the surface engaging inlet foot and body is preferably cut back. The weight is retained in a manner similar to the float. The invention also provides for the weight support member to be attached to the body by the resilient engagement of a ring integral with the member engaging around the outlet from the body. The bumper for the cleaner is shaped for resilient engagement with the weight support member and, in the case of a pool cleaner such as the "Baracuda" brand, around a rigid extension pipe from the outlet of the body such that the contact surface of the bumper is inclined at an angle of less than forty five degrees preferably about 22 degrees, to the normal to the surface being cleaned. Other features of this invention will become apparent from the following description of a preferred form of a pool cleaner made according to this invention. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawing shows a side elevation of a pool cleaner according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the embodiment illustrated the cleaner (generally indicated by numeral (1)) is generally of the type sold under the trade mark "Baracuda" insofar as the main

8 CP 123 Page 7 of 34 operating mechanism for causing movement of the cleaner is concerned. This construction comprises basically a body 2 having a flow passage therethrough, with an inlet 3 at its end operatively nearer the surface to be cleaned, an inlet foot 4 attached to said inlet 3 of the body, and retaining projections 5 for locating the inner periphery of an annular flexible disc 6 surrounding the mouth of the inlet foot. The normally used floats and weights have been removed and replaced in accordance with this invention. The cleaner 1 includes within the body 2 a mechanism (not shown), preferably a special tubular resilient diaphragm (not shown) which flexes, to repeatedly interrupt the flow of water induced through the cleaner during use and thereby cause random movement of the cleaner over a submerged surface to be cleaned. The cleaner 1 has the axis of the body 2 and flow passage therethrough inclined at about forty five degrees to the surface to be cleaned and extending in the direction of travel of the cleaner. The body 2 at the inlet is shaped to be releasably engaged by a replaceable wearing foot 4 which, for pools having smooth surfaces of material other than cementitious material, can conveniently be moulded from polypropelene plastics material. The foot 4 has projections 5 which retain a flexible disc 6 in position around the mouth of the inlet and below an opening (not shown) facing the direction of normal travel of the machine. The disc 6 can rotate around the foot 4. The surface engaging bottom of the foot 4 is circular except that the trailing section 7 of this part is cut back so that it extends only a short distance behind the inlet 3 to the body. This feature enables the pool cleaner to negotiate intersections between surfaces

9 CP 123 Page 8 of 34 to be cleaned which meet at fairly sharp angles. Projecting rearwardly from the upper part of the body 2 is a member 8 terminating in a hollow hemispherical part 9 of a retainer for a suitable float which forms part of the balancing mechanism of the pool cleaner. A hemispherical cap 10 is provided to frictionally engage the part 9 to complete the retainer for the float. The horizontal axis of the part 9 is located about two thirds of the height of the body 2 above the disc 6 and the retainer is located approximately directly over the trailing edge of the body 2. Preferably, supporting protrusions will be provided inside the retainer so that the float will be held securely in one position therein. A member 11 to retain a weight in a similar manner to that described for the float is made integral with a resilient split neck member 12. The neck member 12 can engage around the outlet from the body 2 so that the retainer 13 is located a short distance above and adjacent the edge of the disc 6. This retainer 13 also forms a stop and this stop prevents the disc 6 from flexing upwardly relative to the foot by more than a predetermined amount. This flexing can be determined to give the desired results of operation by experiment. The retainer 13 includes a weight (not shown). This weight has a substantial influence on the movement of the cleaner 1 and because of the leverage provided through the member 11 can be light in comparison with that used in conventional pool cleaners of this type. The two halves of the retainer 13 are constructed so that they can clip together resiliently to retain the weight.

10 CP 123 Page 9 of 34 Fins 14 extend from body 2 and connect part 9 to body 2. Fins 14 act to stabilize body 2 in the lateral direction. A bumper 15 is provided which is supported from a ring 16 at its upper end and by clip formations at its lower end positioned to clip onto the upper part of the member 11. As shown, the ring 16 engages around the upper end of a rigid extension pipe 17 located to project from the outlet from the body 2. The front edge of the bumper 15 is inclined downwardly and rearwardly, for example, at an angle of between twenty and thirty degrees to the normal of the surface being cleaned. This angle differs appreciably from bumpers of a similar nature previously used with pool cleaners of the type described. The effect of the bumper 15 is that where it contacts an obstruction during the movement of the cleaner 1, bumper 15 assists in lifting the disc 6 from the surface and thus breaking the pressure holding the disc 6 to the surface being traversed. This allows the cleaner 1 to move freely until it disengages from the obstruction. The cleaner 1 above described can be made of lightweight materials and is operable under low flow rates of water passing through the flow passage. It operates efficiently and quickly and does not cause damage, under normal conditions of use, to vinyl linings used in some pool constructions. Details of the construction above described can be changed without departing from the scope of the invention. The important factors are the leverage afforded to the float and weight components and restriction of flexing of the forward body edge of the flexible disc 6. The disc 6 itself may also be a type having radially extending ribs from the central opening part-way across the disc 6 and decreasing in height towards the periphery.

11 CP 123 Page 10 of 34 What we claim is: I. A swimming pool cleaner comprising: (a) a forwardly inclined body having a flow passage therethrough; (b) an inlet foot having a water inlet, the inlet foot being attached to the body and connected to the flow passage and when in use, is proximate to a surface to be cleaned; (c) a flexible disc surrounding the water inlet and rotatably connected to the inlet foot and having a peripheral edge; and (d) a stop for preventing upward flexing of the peripheral edge beyond a predetermined amount located forward of the body and above and substantially inward of the peripheral edge. 2. A swimming pool cleaner as claimed in claim I in which the stop incorporates a weight and is located on a support member attached to the body. 3. A swimming pool cleaner as claimed in claim 2 in which the support member is removably mounted on the body. 4. A swimming pool cleaner as claimed in claim 2 in which the support member in turn supports, at least in part, a bumper, the leading edge of which is extended downwardly and rearwardly relative to the body. 5. A swimming pool cleaner as claimed in claim 4 in which the bumper is inclined at between twenty and thirty degrees to the normal to the surface being cleaned. 6. A swimming pool cleaner as claimed in claim 2 in which a float is supported away from the body, behind the centerline of the foot, approximately above the trailing edge of the body and substantially horizontal with or above the weight.

12 CP 123 Page 11 of The swimming pool cleaner of claim 6 wherein the float is supported away from the body at a point approximately two thirds of the height of the body. 8. The swimming pool cleaner of claim 6 wherein the float is located in a retainer which is integrally molded with the body and wherein substantially horizontal fins for stabilizing the pool cleaner extending below the retainer are also integrally molded with the body. 9. A swimming pool cleaner as claimed in claim 2 in which the weight is releasably supported in a retainer which is integrally molded with the member. 10. A swimming pool cleaner as claimed in claim 1 in which the trailing edge of the inlet foot is cut back across the body.

13 CP 123 Page 12 of 34

14 JAPANESE ABSTRACT Page 13 of 34 PATENT ABSTRACTS OF JAPAN (11)Publication number: (43)Date of publication of application: (51)Int.CI. E04H 3/20 (21)Application number: (71)Applicant: JAPAN POOL CO LTD (22)Date of filing: (72)Inventor: YOSHI TANAKA (54) CLEANER FOR BOTTOM OF WATER OF SWIMMING POOLS AND SO ON (57)Abstract: PURPOSE: To provide a pool sweep having a continuously-cycling, flow-interrupting valve at the upstream entrance to an inertial flow chamber. CONSTITUTION: A swimming pool cleaner 1 comprising a head 2 having an inlet 3 and an outlet 4. A flexible circular surface-engaging disc 5 surrounds the inlet 3. The flow passage between the inlet 3 and the outlet 4 includes an inlet chamber 6 immediately upstream of inlet 3 and chamber 7, which is in the form of a tubular section having rigid walls, upstream of inlet chamber 6. A valve 8 is located in the flow passage at the upstream end of chamber 7. At its upstream end valve 8 communicates directly with inlet chamber 6. Cleaner 1 includes a stabilizer fin 10 between head 2 and chamber 7.

15 USP 752 Page 14 of 34 UNITED STATES PATENT 4,208,752 June 24, 1980

16 USP 752 Page 15 of 34 UNITED STATES PATENT 4,208,752 JUNE 24, 1980

17 USP 752 Page 16 of 34 UNITED STATES PATENT 4,208,752 JUNE 24, 1980 CLEANING APPARATUS FOR SUBMERGED SURFACES BACKGROUND OF THE INVENTION: This invention relates to an apparatus for cleaning submerged surfaces, and more particularly to the type of equipment known as "suction sweepers" for swimming pools. Suction sweepers are almost universally used for cleaning submerged surfaces such as swimming pools and the like. Many forms of sweepers have been designed and produced, and some of these have included features which make them more or less self-propelled while suction is applied through the equipment. Alternatively, this desirable self-propelling action has been obtained by applying an auxiliary fluid flow to the cleaning head. One effective and simple type of cleaning equipment has been disclosed and relies easentially on cutting the suction to the operating head of the equipment in a manner which will cause the liquid in the suction pipe to cause the latter to flex and move the head along the surface to be cleaned. In another form of equipment the suction pipe is connected to the common outlet of a pair of rigid passages which are connected through valve seats to the suction inlet to the equipment. A flapper valve is provided in the operating head which, while suction is applied through the equipment oscillates automatically to alternately close off the passages to the suction pipe. Because of the particular arrangement of the passages

18 USP 752 Page 17 of 34 and the valve relative to the inlet opening to the apparatus the action of the valve is such that by striking the valve seats the equipment experiences a driving force that has a net component in a direction parallel to the surface being cleaned. Also, flow is alternately suddenly stopped and accelerated against the inertia of liquid in the two passages, a further impulse force to move the equipment over the surface to be cleaned is generated. The equipment is provided with balancing and stabilizing features which ensure that it will remain properly orientated when submerged and also prevent it from climbing above the level of the liquid submerging the surface to be cleaned. The former apparatus tends to move slowly over the surface to be cleaned while the latter with its rigid passages is cumbersome and bulky. It has been found that the slow operation of the former type of equipment is due more to the type of equipment developed to effect cutting off of the suction and consequently flow through the operating head than to the principle of causing flexing of the suction pipe. It has further been found that an oscillatable valve used to cut off the flow, gives very satisfactory results in practice. SUMMARY OF THE INVENTION It is the object of the present invention to provide equipment which will effectively clean submerged surfaces and which is neat and compact and which can be moved over the surface to be cleaned at a rate of up to about 18 feet per minute. The type of equipment above described has a random movement over the surface to be cleaned and therefore to be effective must move at a useful speed but also not move fast enough to disturb the dirt on the surfaces to such an extent that it will not be sucked through the equipment to be filtered from the liquid.

19 USP 752 Page 18 of 34 According to this invention there is provided apparatus for cleaning submerged surfaces comprising: a balanced operating head having an inlet and an outlet defining respective inlet and outlet axes, the outlet adapted to be swivelably connected to a longitudinally resilient and flexible suction hose, the inlet axis being inclined at an angle of between thirty degrees and sixth degrees to that of the outlet, a passage through the head from inlet to outlet, an oscillatable valve in the head adapted to alternately open and close said passage, a baffle plate in the head between the inlet and valve to form a restricted suction connection between inlet and outlet around the valve and when the passage is closed, the connection being as restricted as practical commensurate with proper valve movement, and the valve being shaped so that liquid flow through the head will cause automatc oscillation thereof between terminal positions The invention also provides for the valve to operate between parallel surfaces provided in the head, for there to be a pair of valve members which oscillate in opposite directions, and for the balancing to be provided by a buoyancy member and a movable weight. Still further features of this invention provide for the inlet to the head to provided though openings allowing flow at right angles to, as well as axially through, the inlet. BRIEF DESCRIPTION OF THE DRAWINGS Many other features of this invention will become apparent from the following description of a preferred embodiment which is made with reference to the accompanying drawings in which:

20 USP 752 Page 19 of 34 FIGS. 1 and 2 show part sectional front and side elevations, respectively, of an apparatus according to the invention. DETAILED DESCRlPTION OF THE PREFERRED EMBODIMENT This form of the invention is designed as a swimming pool cleaning apparatus. Referring to FIGs. 1 and 2, the apparatus consisting of an operating head 1 which basically is of rectangular transverse cross-section having circular inlet 2 and outlet 3 openings. The axis of the inlet 2 is offset from that of the outlet 3 at an angle of preferably forty-five degees. Manufacturing techniques may require that this angle be varied, but it is desirable that it be kept as close to forty-five degrees as possible. The inlet 2 Is made as a cylindrical part 4, the lower part 5 of which is adapted to contract the surface to be cleaned. Openings 6 through the wall of part 5 ensure that water may flow into the inlet. A flexible annular disc 7 is fitted onto the cylindrica1 part 4 and has apertures 8 therethrough so that water may flow therethrough and through openings 6 when auction is applied to draw water through the head. This limits the force with which the head is held against the surface to be cleaned. A peripheral flange 9 is spaced apart from the lower part 5 and serves to retain the disc 7 in position. Most of the flow induced by suction takes place through ports 10 in the wall of the cylindrical part as is more fully described below. The outlet 3 has a swivelable fitting 11 incorporated therein so that the head can be attached to a longitudinally resilient suction pipe 12 which is also flexible. An oscillatable valve 14 is located within the head between the inlet 2 and outlet 3 so

21 USP 752 Page 20 of 34 that it may open or close a passage 13 through the head between the inlet and outlet. The valve 14 is of substantially triangular cross-section so that it may oscillate about its apex adjacent the outlet 3. The base of the valve 14 is slightly peaked as indicated at 16 so that it may move over and cooperate with a partition member 17 located in the inlet end of the head 1 when water is caused to flow through the opening 18 into the head 1. On the side of the valve opposite the f1ow passage 13 through the head is a suction communication which is designed so that there is as restricted an opening between inlet and outlet of the head as is commensurate with the proper operation of valve 14. Water flow through the suction communication is therefore greatly reduced compared to that through the passage 13. The suction communication is adapted to be shut off when the flow passage is open and is only open for a brief period when the valve 14 closes the flow passage. The shape and size of the valve 14 in the head together with the location of the partition member 17 constricts the suction communication to a size which prevents appreciable liquid flow therethrough. Internal formations indicated at 19 are provided in the head 1 to constrain the movement of the valve 14 in the head and form valve seats 20 and 21 to close off the flow passage through the head 1. The shape of the base of valve 14 providing peak 16 enables the space 22 between the valve and member 17 to remain substantially constant as the valve moves between its terminal positions and is also balanced. The pivot point 23 of the valve 14 is located on the opposite side of the axis of the outlet 3 to the opening 18 so that it operates partially in a chamber 24 in the head 1 offset from the axis of outlet 3. The valve 14 has a clearance between the sides of the body adjacent which it oscillates.

22 USP 752 Page 21 of 34 With the construction above set forth it has been found that when the head is submerged and a swimming pool suction filter applied to the pipe 12 the flow of water causes the valve to oscillate between its two terminal positions. In one such position the flow is substantially full and direct through opening 18 and passage 13 to outlet 3, while in the other there is maximum reduction in liquid flow through the head. This results in use in an intermittent cut off of flow through the head as the valve 14 oscillates between its terminal positions, and this in turn causes pulsations which resu1t in longitudinal contractions and relaxations in the longitudinally resilient suction pipe from the head to the outlet from the swimming pool to its filter unit. In consequence of these contractions and relaxations and a simultaneous reduction and increase of the force applied to hold the disc 7 against the surface to be cleaned, a step by step movement of the head takes place over the surface to be cleaned. The movement is automatic but random and to control this a buoyancy chamber 25 is provided. This will preferably be provided with foamed polystyrene floatation material. This chamber ensures that while head will sink onto the surface to be cleaned it will nevertheless be correctly orientated thereto. Also because the apparatus can operate on vertical walls it is necessary to provide suitable counterbalancing to prevent the head from climbing above the water level and allowing air to be drawn through the system. This can be easily effected in a known manner by having a freely movable weight 26 in a Vee-shaped guide attached to the head across the width thereof. It may be fitted to either the upper or lower surface of the head. To prevent the apparatus from driving itself into postions where it cannot move, a flexible pointed guide 27 in the form of an open triangle of resilient plastics material is fitted to project from the head in the opposite direction to arrow "A", which is the

23 USP 752 Page 22 of 34 direction of normal movement of the apparatus In use all that is necessary is for the swimming pool suction filter equipment to be connected to the head through longitudinally resilient and flexible piping and the head placed on the floor. It will then move randomly over the floor and, if the sides and bottom of the pool do not meet too sharply, also the sides of the pool. As the disc 7 moves over the floor it loosens any dirt thereon which is sucked through ports 10 and through the head into the filter. It can be allowed to operate whenever the filter is operated and requires no attention. It will be appreciated that the embodiment has been described with the valve oscillating in a plane which is vertical to the surface to be cleaned. It is, of course, possible to have the valve work in a plane at right angles to this vertical plane and also to make other modifications to the constructions without departing from the scope of this invention. The apparatus will preferably be moulded in plastics material, and polypropylene bas been found suitable for use in the manufacture or the valve. CLAIMS OMITTED

24 USP 848 Page 23 of 34 UNITED STATES PATENT 4,761,848 August 9, 1988

25 USP 848 Page 24 of 34 UNITED STATES PATENT 4,761,848 August 9, 1988

26 USP 848 Page 25 of 34 UNITED STATES PATENT 4,761,848 August 9, 1988 SUCTION-OPERATED AUTOMATIC SWIMMING POOL CLEANER BACKGROUND OF THE INVENTION The present invention relates to apparatus for cleaning the submerged surface of a swimming pool; and more particularly, it relates to an automatic pool cleaner of the water interruption type. In a water interruption pool cleaner, water flow through the head of the device is created by suction applied to an outlet connected by a flexible hose to the swimming pool water circulation system. An automatic valve member in the head interrupts the water flow and simultaneously reduces suction adherence to the submerged surface. The sudden interruption of water produces a change in momentum of the mass of water in the device and, through the fundamental action/reaction principle, creates a motive force on the device.. Water interruption pool cleaners include a head having an open mouth inlet to admit water. Water is sucked through the head by suction applied to an outlet provided for connection to a flexible hose. The water flow passage between the inlet and the outlet is inclined at an angle. The head, however, is configured to have the open mouth lie in a substantially horizontal plane to facilitate cleaning planar, submerged surfaces. Accordingly, the water flow path through the head from the open mouth to the outlet is disposed at an angle with respect to the planar surface to the cleaned. The motive force imparted to the head of the device upon an interruption of water flow is along a line of action following the direction of water flow. The net motive force includes

27 USP 848 Page 26 of 34 a component parallel to the plane of the submerged surface and in the direction of the hose connection. Thus, forward movement in normal operation is in the direction of the outlet and connected flexible hose. This movement presents a problem when the device encounters an obstruction such as, for example, steps in the pool, a pool ladder on a wall, or a bench formed in a pool wall, in that the device becomes lodged between such obstructions and the pool wall. Further, in pools having substantially right angle corners, the device can become lodged in a corner and cannot extricate itself. Heretofore, the problem of a water interruption pool cleaner becoming lodged and unmovable by reason of an obstruction in the pool has been addressed by various bumper guard structures affixed to the device. While helpful, bumper guards are not wholly satisfactory. The bumper guards are themselves prone to lodging and entangling with obstructions. Also, deflection of the device away from obstructions can lead to certain areas of the pool remaining cleaned. Accordingly, there continues a need for a solution to the problem. SUMMARY OF THE INVENTION A suction-operated pool cleaner having a head with an outlet for connection with a flexible hose and an automatic valve within the head for creating motive force includes a valve in the outlet for venting applied suction to ambient in response to contact of the pool cleaner with obstructions to movement. The diversion of applied suction from the head reduces suction adherence of the head to the submerged surface and permits reorientation of the cleaner so as to be freed from the obstruction. The valve may comprise a port opening in the outlet and a valve member actuated upon contact of the pool cleaner with an obstruction. The port is closed during normal operation of the pool cleaner. Upon contact with an obstruction, the valve member opens the port and vents the applied suction.

28 USP 848 Page 27 of 34 BRIEF DESCRIPTION OF THE DRAWINGS A written description setting forth the best mode presently known for carrying out the present invention, and of the manner of implementing and using it, is provided by the following detailed description of preferred embodiments which are illustrated in the attached drawings wherein FIG. 1 is a cross section of a water interruption type pool cleaner that utilizes a flexible tubular member as the valve for effecting the water interuption function; FIG. 2 is an enlarged view of a portion of the cleaner of FIG. 1; FIG. 3 is a section taken along lines 3-3 of FIG. 1; FIG. 4 is an illustration of. water interruption pool cleaner in accordance with the present invention having a valve in the outlet for venting applied suction to ambient upon contact with an obstruction in the pool; FIG. 5 is a detailed illustration of the outlet valve of the pool cleaner shown in FIG. 4. DETAILED DESCRIPTON Referring to FIGS and 3. the inner body portion of an automatic pool cleaner of the water interruption type is shown having an operating head 20 and a foot 30 for the cleaner to contact the surface to be cleaned. The head 20 includes an inlet mouth 32 to a flexible tubular valve member or diaphragm 40. The inlet end 41 of valve 40 is enlarged to define a flange 42 which engages and seals against a flange 51 on the body 50. The ontlet 43 of valve 40 engages an internal collar 52 formed by plate 90. Engagement is by a circumferential recess in the upper end of valve 40. The valve is insertable into body 50 through mouth 32. The outlet end 43 of valve 40 communicates with an elongated rigid tubular section 44 and outlet 46. The flexible valve member 40 is housed within body 50 to define a chamber 60. The upper or downstream end of chamber 60 is defined by a plate 90. Plate 90 as shown in FIG. 3 is substantially circular as is the cross section of body 50 above or downstream of plate 90. Below or upstream of plate 90, body 50 is square in shape. An annular space 100 exists between body 50 and a section 110 of the rigid tubular section 44. The end of

29 USP 848 Page 28 of 34 section 110 is inserted into valve 40. A plurality of ports 92 in plate 90 provide for fluid communication between the interior of chamber 60 and the annulus 100. The head has an outlet 33 for connection with a flexible hose. The outlet includes a substantially rigid conduit 120 which fits loosely around rigid section 44 of the tubular passageway above the valve 40. Lower end 121 of conduit 120 defines the lower portion of annular space 100 permitting suction communication from 100 through slots 92 to chamber 60. End 121 has one or more peripheral grooves 122 on its outer surface. A bushing 130 is press fit into the round upper end portion of body 50. Bushing 130 has one or more peripheral ridges 132 which snap or otherwise fit loosely within the grooves 122 to lock conduit 120 to the bushing. The conduit 120 is joined to body 50 by simply forcing bushing 130 into the circular upper end portion of the body. In operation, the chamber 60 has a suction connection to the outlet 46. The chamber becomes filled with water upon immersion of the device through the loose connection at conduit 120 and bushing 130 and through annular space 100. An inlet to chamber 60 may be provided if desired. It should be clearly understood that it is not essential for the diaphragm valve member to completely cut off flow. It is satisfactory if there is produced an interruption of the water stream through the tubular passageway sufficient to induce movement in the device. Expansion of the diaphragm valve member and release for it to reassume its relaxed condition is by the creation of a pressure differential across the valve member walls, i.e., a pressure difference between the chamber 60 and the interior of the valve member. This is created by the suction applied to the tube 120. The valve member is

30 USP 848 Page 29 of 34 autonomously opened and closed. Applied suction initially causes valve 40 to openl; but with water flow established, the pressure within valve 40 drops below that of chamber 60. The valve thus closes. The cycle autonomously repeats. As indicated in FIG. 1, the head and outlet conduits as disposed at an angle with respect to the plane of the head portion or foot 35 which rests on the pool surface. Movement is to the direction in which the pool cleaner is inclined; i.e., toward the flexible hose. When suction is applied to outlet 33, suction adherence of the head to the submerged pool surface is created, and water flow between the inlet 32 and the outlet is induced. The valve 40 also begins its autonomous action. Contraction of valve 40 interrupts water flow and imparts motive force to the head. Simultaneously, suction adherence of the head to the pool surface is reduced. As operation continues, the pool cleaner moves across the pool surface vacuuming debris from the pool and delivering it into the pool's filter-circulation system. Referring now to FIG. 4, the pool cleaner of FIGS 1-3 is shown with an outer housing 130 shrouding the inner body. The pool cleaner also carries a flange 132 and a peripheral disc 134. In FIG. 4, the attachment of outlet conduit 120 to a flexible hose 136 is shown. Further shown in FIG. 4 and FIG. 5 is a valve mechanism 140 located in the outlet 33 upstream diaphragm valve 40. The valve mechanism includes a port opening 142 in the conduit 120. An O-ring seal 144 is provided at the port opening to facilitate sealing of the port by valve member 146 during normal operation of the pool cleaner. Valve member 146 is actuated by a lever 148 which is pivotally affixed to conduit 120. A clevis and pin arrangement 147 is used and the lever arm is biased with a compressed spring 150 to cause valve member 146 to normally close port 142.

31 USP 848 Page 30 of 34 The lever 148 is disposed in a plane substantially parallel to the vertical plane containing the centerline axis of the outlet conduit; and preferably, the lever lies in the same plane. Lever 148 is configured to extend away from the outer housing 130. This positions the lever for contact with obstructions in the pool (i.e., steps, ladders, benches) which might entangle, block or otherwise impede or entrap the pool cleaner and prevent its movement. In normal operation, valve member 146 closes port 142. When the pool cleaner moves against an obstruction, lever 148 is engaged and causes valve member 146 to be actuated so as to open port 142. Opening port 142 vents the suction applied to outlet conduit 120 and causes suction adherence of the head to the pool surface to be substantially reduced for release from the pool surface. The venting of port 142 and the diversion of applied suction from valve 40 and mouth 32 need not be a complete removal of applied suction therefrom. The applied suction need only be reduced sufficiently to effect a sufficiently reduced adherence of the head to the pool surface to permit hose flexure to reorient the pool cleaner. In normal operation, the hose connected to the outlet is in compression. Upon venting the applied suction through port 142, the hose will relax and extend itself in a sudden movement or jerking motion. This flexing of the hose will typically change the orientation of the pool cleaner and allow it to move free of the obstruction. The venting port and lever arrangement is applicable to the commercial1y available BARACUDA ALPHA pool cleaner. The outlet conduit 120 in that device has a diameter of about l ¼ inch I.D. The port opening 142 to be provided therein may be in the order of 1" I.D.. Given the vacuum drawn by conventional swimming pool pumps, such port size appears to provide a sufficient reduction in applied suction upon venting of the port. The size of the port will, of course, vary depending upon the vacuum drawn by the pump used and the dimensions of the device, as would be apparent to a person of skill in the art.

32 USP 848 Page 31 of 34 The foregoing description has been directed to a particular preferred embodiment for purposes of explanation and illustration. It will be apparent, however, to those skilled in the art that the structure may be changed without departing from the essence of the invention. CLAIMS OMITTED

33 Page 32 of 34 B2. Your client instructs you to enter the national phase in Canada on the thirtymonth deadline in respect of an International PCT Application. Your client asks you to name Company X as the Applicant even though Company Y is named as the Applicant on the published International PCT Application. They inform you that subsequent to the international filing date, the invention was sold by Company Y to Company X but that no steps were taken to record the change in ownership at WIPO. They have also advised you that chain of title documentation will be forthcoming. You enter the national phase in Canada, complying with your client s request and name Company X as the Applicant. (a) What title documentation is required and when must the title documentation be filed? 3 marks (b) What is the effect of failing to submit the title documentation by the deadline of subsection (a)? 1 mark (c) Just prior to the deadline to file the title documentation, your client informs you that they will not have the title documentation available by the deadline. What do you do to keep the application pending? 2 marks B3. Your client seeks advice with respect to the filing of an Industrial Design Application relating to Widget A based on an earlier filed U.S. Design Application. Your client tells you that the U.S. Design Application includes multiple sets of figures showing different versions of Widget A and that some of the drawings show Widget A in its environment. Your client asks you if all of the figures can be maintained in a single Canadian Industrial Design Application and if there are any special drawing requirements that must be met when showing environment. Advise your client. 2 marks

34 Page 33 of 34 B4. Company X files a U.K. informal application on May 15, On May 15, 2005, Company X files a U.S. provisional application for the same invention disclosed in the U.K. informal application. On April 15, 2006, Company X files corresponding utility applications in the U.S., Canada and Europe claiming priority on the U.S. provisional application. (a) Comment on the priority claims made through this filing strategy. 3 marks (b) Does your answer change if the U.S. provisional application was filed on May 25, 2005? Explain. 3 marks B5. You are handling a pending Canadian patent application corresponding to an earlier filed U.S. application on behalf of a U.S. attorney. The U.S. attorney advises you that the parent U.S. application has been allowed and that a U.S. continuation application has been filed. The U.S. attorney wants you to file a divisional application in Canada including claims corresponding to those pending in the U.S. continuation application. (a) Recommend a course of action to the U.S. attorney. 4 marks (b) Does your recommendation change if a notice of allowance has been received on the pending Canadian patent application? Explain. 2 marks (c) What if the final fees have been paid? 1 mark B6. Your client conceives of an invention on June 1, After over three years of secret, diligent work, your client reduces the invention to practice and files a patent application in the U.S. Patent Office on September 15, The U.S. application has finally been picked up by the Examiner for review. In the first Official Action, the

35 Page 34 of 34 Examiner cites U.S. Patent No. Y,YYY,YYY issued on March 15, The YYY patent does not include a priority claim and stems from an application filed on April 1, The Examiner alleges that the cited YYY patent anticipates your client s claimed invention. Upon review of the cited YYY patent, you agree with the Examiner s assessment. Your client now seeks your assistance in formulating a response to the Official Action. (a) Assuming that the application filed on April 1, 2001 was the first filed application for the invention claimed in the YYY patent, advise your client. 3 marks (b) Does your answer change if U.S. Patent No. Y,YYY,YYY stems from an application filed on September 15, 2002? Explain. 2 marks B7. Your client has become aware of Canadian Patent Application No. X,XXX,XXX. Your client advises you that the invention claimed in this patent application has been commonplace in the industry for years and was used publicly well before the filing date of the application. Your client wants to prevent the application from issuing. (a) What can your client do? 2 marks (b) What can your client do if it turns out that the application referred to above is in fact an issued patent? 2 marks