GB2254894A

GB2254894A - Pump for fluid, and suction cleaning device incorporating same.

Info

Publication number: GB2254894A
Application number: GB9106683A
Authority: GB
Inventors: Peter Brooke Evans
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-03-28
Filing date: 1991-03-28
Publication date: 1992-10-21
Anticipated expiration: 2011-03-28
Also published as: GB9106683D0; GB2254894B

Abstract

A pump comprises an elongate cylinder element (4) divided by elements (5) into a number of cylinder spaces in which piston elements (3) are reciprocable, the piston elements being mounted on a common piston rod (2), and passages (6, 7) for flow of fluid connected to each of said cylinder spaces. The pump enables a fluid flow to be produced as that of a single piston and cylinder of long stroke. The invention also provides a suction cleaning device in which the pump is connected to a chamber (1) for receiving collected material, e.g. dog excreta, and having a collection nozzle (13), the pump construction enabling an effective air flow to be produced in a compact device. <IMAGE>

Description

Title: Pump for fluid, and suction cleaning device incorporating same Description of Invention This invention relates to a suction cleaning device for collecting material, and to a pump which has been devised primarily for use in the suction device, although as described hereafter the pump is capable of more general application.

The suction cleaning device has been devised with the problem in view of the collection of dog excreta from public places. The deposition of excreta by uncontrolled dogs is a major problem in the United Kingdom, and apart from the offensive nature of the material it is established that it is a potential health hazard. Public awareness of the problem of fouling by dogs is becoming more acute, and dog owners are under increasing pressure to clean up after their pets.

Various scoop devices and plastic bags are available for this purpose, but the use of these entails the responsible pet owner bending down to remove the deposited material and the risk of contact therewith. Industrial techniques for removing the material, e.g. by freezing it to render it easily collectable, are not suitable for use by private individuals.

It is therefore one object of the present invention to provide a suction device which is usable by the responsible pet owner without great inconvenience.

It will of course be appreciated that the device is usable more generally for cleaning tasks.

It is recognised that the effectiveness of a suction cleaning device is dependent on the magnitude of the air flow which it creates. Thus electrically powered suction cleaners have relatively powerful motors. If the air flow has to be induced by the efforts of the user of the device, an extremely large bellows, or piston and cylinder pump of large bore and/or stroke would be required to cause sufficient air flow for an effective collection of material. This would render the device clumsy and not readily usable and/or carriable. It is therefore a further object of the invention to provide a pump suitable for inducing air flow in a suction cleaning device, which is of compact design and simple construction.

According to one aspect of the invention, I provide a pump comprising an elongate cylinder element, means dividing the cylinder element into a number of cylinder spaces, a number of piston elements supported at spaced positions on a piston rod element so as to be disposed in respective ones of said cylinder spaces, said cylinder element and piston rod element being reciprocable relative to one another, and a passage connected to said cylinder spaces for flow of fluid displaced thereby.

In a pump according to the invention, the division of the cylinder element into a number of individual cylinder spaces containing respective piston elements has the effect that a relatively short stroke of the piston rod element displaces a quantity of fluid equivalent to that of a much longer stroke of a single piston within a cylinder. Therefore a large flow of fluid can be produced when the pump is operated through a stroke which is much shorter than the overall length of the cylinder element. This renders the pump adaptable for use in a compact and convenient suction cleaning device.

According to another aspect of the invention, I provide a suction device for collection of material, comprising a chamber for receiving the material, a pump according to the first aspect of the invention, having its passage for displaced fluid connected to said chamber whereby it is operable to exhaust air from said chamber, and a nozzle for application to the material to be collected and leading into the receiving chamber.

These and other features of the invention will now be described by way of example with reference to the accompanying drawings, wherein Figures 1,2 and 3 are longitudinal sections through a first embodiment of such device according to the invention, with the pump thereof respectively in its mid-stroke position and at opposite limits of its stroke; Figure 4 is a cross section on the line A-A of Figure 1: Figure 5 shows a modification of the receiving chamber of the device:: Figures 6 to 8 are enlargements showing details of the device; Figure 9 is a longitudinal section through a further embodiment of device according to the invention; Figure 10 is a cross section on the line B-B of Figure 9; Figure 11 is a longitudinal section showing yet a further embodiment of device according to the invention; Figures 12 and 13 are enlarged details of parts of Figure 11; and Figure 14 is a section on the line C-C of Figure 11.

Referring firstly to Figure 1 of the drawings, this embodiment of suction device according to the invention comprises a receiving chamber 1 which is of generally cylindrical form with end walls from one of which extends a collecting nozzle 13 with an inclined end 17, the collecting nozzle defining a passage leading into the chamber 1. A baffle or filter element 12 is disposed in the chamber 1 adjacent the opposite end thereof, and to such opposite end is connected a hollow piston rod 2 which affords a passageway for air flow. A nonreturn valve 9 is disposed within the end of the piston rod 2 where it is connected to the chamber 1, the permitted direction of air flow through the non-return valve 9 being as indicated by the arrow thereon.A cylinder element 4 is disposed about the piston rod 2, and is divided by radially inwardly extending annular elements 5, which seal with the external surface of the piston rod 2, into individual cylinder spaces 15. Radially outwardly extending piston elements 3 provided on the piston rod 2 seal with the internal surface of the cylinder element 4, and further cylinder spaces 16 are thus defined at the sides of the piston elements 3 opposite to the cylinder spaces 15. Respective vents 6 provide for communication between the cylinder spaces 15 and the passage in the interior of the hollow piston rod 2, and respective vents 7 provide communication between the spaces 16 and the external atmosphere.At its end opposite the receiving chamber 1 the cylinder element is closed, and vents 8 provides communication between the space defined at this closed end of the cylinder element and the external atmosphere. A further non-return valve 10 is disposed within the corresponding end of the hollow piston rod 2, the direction of permitted air flow through the valve being again indicated by an arrow. A spring 11 biases the cylinder element 4 axially away from the receiving chamber 1: the cylinder element can be manually pressed in the direction of arrow 18 against such spring biasing. A locking device, not shown, would be provided for retaining the cylinder element in its extreme position of movement towards the receiving chamber 1, as depicted in Figure 2. A removable sealing cap 14 is provided for closing and protecting the end 17 of the nozzle 13.

To use the device for the collection of material, e.g. of dog excreta, the sealing cap 14 is removed from the nozzle 13 and the locking device is released, allowing the device to expand under the action of spring 11 to its position shown in Figure 3. During this expansion, air within the cylinder spaces 15 passes from the chambers 15 into the hollow piston rod 2, thus closing the non-return valve 9 and opening the non-return valve 10 so that such air can exhaust to atmosphere through the vents 8. Vents 7 permit air to enter the spaces 16 during such expansion. The end 17 of the nozzle 13 is then placed over the material to be collected. By applying force by hand in the direction of arrow 18 the device is contracted against the pressure of spring 11 to the position shown in Figure 2.

During this operation, air in spaces 16 is vented to atmosphere via vents 7 and 8 while the increase in volume of the cylinder spaces 15 draws air into such spaces through the vents 6 and, by the non-return valve 9, into the hollow piston rod 2.

This causes a partial vacuum to be produced within the receiving chamber 1 and nozzle 13, thus drawing material into the receiving chamber where it is retained.

The filter or baffle 12 prevents collected material from being drawn into the nonreturn valve 9 and the hollow piston rod 2.

The cylinder element 4 is reciprocated by the operator until all the material to be collected has been drawn into the receiving chamber. At this stage the device is returned to its contracted position as shown in Figure 2, the locking device brought into operation, and the sealing cap 14 replaced. Subsequently, at a convenient time, the receiving chamber is opened at a sealable joint (not shown) and the contents disposed of as required.

Figure 4 shows a diagrammatic section of the hollow piston rod 2, a piston element 3 thereon, the cylinder element 4, and the vents 7 in the cylinder element.

Figure 5 shows in longitudinal section an arrangement whereby a disposable bag and ejecting mechanism may be incorporated within the receiving chamber 1. A disposable bag, e.g. of paper, is indicated at 19, retained over the innermost end 20 of the nozzle 13 by a pressure plate 21, supported by frame 22 which abuts the baffle or filter element 12. When full, the disposable bag may be removed from the pressure plate and support frame by opening the receiving chamber at a sealable joint, not shown. Alternatively, without using a disposable bag, the pressure plate 21 may be used as a ejector mechanism by opening the receiving chamber at a sealable joint adjacent to the baffle or filter element 12, and withdrawing the receiving chamber body from the pressure plate and support frame, thereby ejecting the contents of the receiving chamber.

Figure 6 shows on an enlarged scale an example of a means by which one of the radially inwardly extending elements 5 may be secured within the cylinder element 4. A sleeve 23 on the outside of the cylinder element 4 holds the element 5. Vents 7 are also shown in this drawing.

Figure 7 shows on an enlarged scale how the piston elements 3 may be mounted on the hollow piston rod 2. The latter may be in sections, joined by sleeves 24 to which the piston elements 3 are connected. The vents are omitted from this figure, for clarity.

Figure 8 shows in detail a typical construction of one of the non-return valves 9, 10. It comprises a valve body 25 with a perforated transverse screen 26 to which a valve element 27 of flexible material, having flaps 29, is fixed. If the air pressure on the side 28 of the screen 26 exceeds that on the opposite side thereof, flaps 29 of the flexible material can move away from the screen 26 allowing air to flow through the valve in the direction of arrow 30. If the relative air pressures are reversed, the flexible material lies against the screen 26 preventing reverse air flow.

In possible modifications of the device, collector ducts may be provided for air issuing from vents 7 and 8, which may contain odours. Such contaminated air could be led to a suitable discharge point or points on the device.

The inlet nozzle may be disposed other than on the main axis of the device. The sealing cap 14 may be hinged, and remain attached to the body of the receiving chamber when the inlet nozzle is exposed for use. Locking clips may be provided for retaining such a hinged sealing cap in its open and closed position.

The device may be fitted with one or more carrying handles or attachment points for a carrying strap.

When used for its intended purpose, it may be operated by one hand allowing the user's other hand to remain free for other tasks. The device may be used as a staff to ward off unwanted attention from animals, or the like.

The inlet nozzle and receiving chamber may be combined to produce a single disposable "throw-away" unit, thus reducing the overall length of the device when not in use.

The receiving chamber may be telescopically contractable when not in use, to reduce the overall length of the device when the receiving chamber is empty.

It will, of course, be appreciated that the pump part of the device may be modified by the use of any number of cylinder spaces, and they may be of cross sections other than circular.

Referring now to Figures 9 and 10 of the drawings, this shows a further embodiment wherein the pump part of the device is made double acting, utilising six cylinder spaces. The same reference numerals are used as are used hereinbefore, for parts of corresponding design and function, and the above description applies with the following differences.

In this embodiment, instead of vents 6, 7 and 8, one-way valves 31, 32 are provided. Additional one-way valves 33, 34 are also provided, providing communication between the cylinder spaces 16 and the interior of the hollow piston rod 2, and between the cylinder spaces 15 and the external atmosphere, respectively. The end of the hollow piston rod is closed at 35. The operation of this embodiment is substantially as above described, but since the pump is double acting air is drawn through the receiving chamber 1 on both the expansion and contraction strokes of the pump.

Figure 10 shows an example of how one-way valves 32 may be arranged. An annular expandible seal 36 of flexible material is disposed around the cylinder element 4, covering vent apertures. When the pressure inside the cylinder element 4 exceeds that of the external atmosphere, the flexible material 36 lifts away from the surface of the cylinder element permitting flow of air as indicated by the arrows. Analogous arrangements may be used for the one-way valves 31, 33 and 34.

Referring finally now to Figures 11 to 14 of the drawings, this shows a further modified embodiment of the invention. Again the same reference numerals are used for parts corresponding to those above described. The device comprises an elongate body which is formed at one end with a receiving chamber 1, nozzle 13 with collecting end 17, and baffle or filter element 12. The majority of the body of the device is of the cross sectional shape shown in Figure 14, comprising a cylinder element 4, and, alongside the cylinder element, a part defining a passage 52. The cylinder element is divided by radially inwardly extending elements 5 into individual cylinder spaces, within which piston elements 3 on a piston rod 37 are reciprocable. Non-return valves 38, 39 provide for communication between the passage 52 and the cylinder spaces 15, 16 defined on opposite sides of the piston elements 3, while non-return valves 40, 41 provide for communication between the cylinder spaces and the external atmosphere. A compression spring 11 within the cylinder space 16 immediately adjacent the receiving chamber 1 biases the assembly of piston rod 37 and piston elements 3 outwardly, and the piston rod terminates in a grip 53 by which it can be pressed in the direction of arrow 18 against the spring 11. A non-return valve 9 is provided in the passage 52 adjacent the receiving chamber 1.

The non-return valves 38, 39, 40, 41 may be as generally described above in relation to Figure 8 of the drawings.

Figure 12 shows how each of the elements 5 may be secured within the cylinder element 4. A annular groove 42 is formed in the cylinder element, and circlips 43 engaging in such groove retain the element 5.

Figure 3 shows how piston elements 3 may be secured to the piston rod 37. The piston elements 3 are mounted on sleeves 44, which are retained on the piston rod by a spring clip 45 engaging in a groove 46 in the rod.

Operation of this embodiment of the device is similar to that described above with reference to Figures 9 and 10 of the drawings. The pump is double acting, so that air is drawn through the receiving chamber 1 both as the piston rod is pressed in the direction of arrow 18 and returned in the opposite direction on the action of spring 11. During the former, contraction, stroke air within the cylinder spaces 16 vents to atmosphere by way of the non-return valves 40. Air is drawn into the cylinder spaces 15 through non-return valves 39, from the passage 52. On the expansion stroke under the action of spring 11, air within the cylinder spaces 15 vents to atmosphere via non-return valves 41, while air is drawn from the passage 52 into the cylinder spaces 16 by way of non-return valves 38.

This embodiment of the device may incorporate any of the above described features for retention and disposable of collected material, and for the sealing of the inlet nozzle.

In this embodiment, the part of the passage 52 as indicated at 47 forms a carrying handle. The space 48 adjacent the handle may be used to house, for example, a reservoir for disinfectant, which may be dispensed by, for example, a trigger operated pump, to issue adjacent the end 17 of the nozzle to clean it and its surrounding area.

It will be appreciated that other variations and modifications in the device may be made.

It will further be appreciated that the principle of the pump used in the suction device may be applicable for other purposes, in situations where a relatively great flow of fluid can be induced by an elongate cylinder without requiring a correspondingly long stroke of a piston element, which long stroke would be inconvenient. By way of example, the pump may have application in domestic and/or gardening situations, e.g. for collection of liquid or for spraying.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A pump comprising an elongate cylinder element, means dividing the cylinder element into a number of cylinder spaces, a number of piston elements supported at spaced positions on a piston rod element so as to be disposed in respective ones of said cylinder spaces, said cylinder element and piston rod element being reciprocable relative to one another and a passage connected to each of said cylinder spaces for flow of fluid displaced thereby.

2. A pump according to Claim 1 wherein said piston rod element is hollow to define said passage.

3. A pump according to Claim 1 or Claim 2 comprising respective nonreturn valve elements connecting said passage to said cylinder spaces.

4. A pump according to any one of Claims 1 to 3 comprising respective non-return valve elements connecting said cylinder spaces to external atmosphere.

5. A pump according to Claim 4 comprising respective non-return valve elements connecting the cylinder spaces on opposite sides of each of said piston elements to said passage and to external atmosphere, whereby flow of fluid in said passage is caused in both directions of relative movement of the cylinder element and piston elements.

6. A suction device for collection of material, comprising a chamber for receiving the material, a collecting nozzle for application to the material to be collected, and leading into the receiving chamber, and a pump according to any one of the preceding claims and having its passage for displaced fluid communicating with the receiving chamber for exhaustion of air therefrom.

7. A device according to Claim 6 wherein said cylinder element of the pump constitutes a handle for the device.

8. A device according Claim 7, as appendant to Claim 2, wherein said piston rod is fixed to said receiving chamber and said cylinder element is reciprocable thereon, and further comprising spring means biasing said cylinder element away from said receiving chamber.

9. A device according to Claim 6 wherein said passage constitutes a handle for the device.

10. A device according to any one of Claims 6 to 9 comprising a nonreturn valve element in said passage, adjacent said receiving chamber.

11. A device according to any one of Claims 6 to 10 comprising a removable cover and closure member for said nozzle.

12. A device according to any one of Claims 6 to 11 comprising filter means for preventing collected material from entering said passage.

13. A device according to any one of Claims 6 to 12 comprising a disposable bag for collected material in said receiving chamber.

14. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.

14. A pump, or a suction device incorporating a pump, substantially as hereinbefore described with reference to Figures 1 to 8, Figures 9 and 10, or Figures 11 to 14 of the accompanying drawings.

15. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.

Amendments to the claims have been flied as follows

1. A pump comprising an elongate cylinder element, means diyiding the cylinder element into a number of cylinder staves, each space tro- vided with connection to external atmosphere, a number of piston elements supported at spaced positions on a piston rod element so as to be disposed in respective ones of said cylinder spaces, said cylinder element and piston rod element being reciprocable relative to one another and a passage connected to each of said cylinder spaces for flow of fluid displaced thereby.

3. A pump according to Claim 1 or Claim 2 comprising non-return valve elements in said passage to control the direction of floiiP therein.

4. A pump according to Claims 1 or Claim 2 therein 3aiE passage ic closed at one evtremity anci whereeby a non-return valve in said passage controls the direction of flow therein.

5. A pump according to Claim 4 comprising on opposite sides of each of said piston elements respective non-return valve elements connecting the cylinder spaces to said oassasg,e and to external atmosphere, hereby floa of fluid in said massage is caused in both directions of relative movement of the cylinder element and piston elements.

6 suction device for collection of material. comprising a chamber for receiving the material, a collecting nozzle for application to the material to be collected. and leading into the receiving chamber and a pump according to any one of the preceding claims and having its passage for displaced fluid communicating with the receiving chamber for exhaustion of air therefrom.

10. A device according to any one of Claims 6 to 9 comprising a removable cover and closure member for said nozzle.

11. A device according to any one of Claims 6 to 10 comprising filter means for preventing collected material from entering said passage.

12. A device according to any one of Claims 6 to ii comprising a disposable bag for collected material in said receiving chamber.

13. A pump, or a suction device incorporating a pump, substantially as hereinbefore described with reference to Figures 1 to 8, Figures 9 and 10, or Figures 11 to 14 of the accompanying drawings.