GB2073827A

GB2073827A - A combined air compressor and vacuum device

Info

Publication number: GB2073827A
Application number: GB8011809A
Authority: GB
Original assignee: Well Men Ind Co Ltd
Current assignee: Well Men Ind Co Ltd
Priority date: 1980-04-10
Filing date: 1980-04-10
Publication date: 1981-10-21
Also published as: GB2073827B

Abstract

A combined compressor and vacuum cleaner device is proved suitable for inflating a motor vehicle tyre in which a high pressure - low volume output is required for inflating an article in which a low pressure - high volume output is required or vacuum cleaning the vehicle interior. The device has an electric motor 1 with an armature shaft 2 carrying a first clutch element 3 at one end and a second clutch element 4 at the other end. A reciprocating type air compressor unit 5 has a clutch element 6 selectively releasably engageable by the first clutch element 3 of the motor 1 for actuation thereby. A vacuum cleaner fan unit 7 has a clutch element 8 selectively releasably engageable by the second clutch element 4 of the motor for rotatable actuation thereby. The motor 1 is mounted for displacement, in response to selectively actuable control means 11, 13 between a first drive position in which the first clutch element 3 and the air compressor unit clutch element 6 are in driven engagement with the second clutch element 4 and fan unit clutch element 8 disengaged and a second drive position in which the second clutch element 4 and fan unit clutch element 8 are in driven engagement with the first clutch element 3 and compressor unit clutch element 6 disengaged. <IMAGE>

Description

SPECIFICATION A combined air compressor and vacuum device This invention relates to a combined air compressor and vacuum cleaner device particularly, but not exclusively, suitable for inflating a motor vehicle tyre or vacuum cleaning the vehicle interior. Such a device preferably is portable.

Individual portable air compressors suitable for use as motor vehicle tyre inflators and individual vacuum cleaners suitable for vacuum cleaning a motor vehicle interior, are known. Thus anyone wishing to have equipment for tyre inflation and vacuum cleaning would need to have both an air compressor and a vacuum cleaner. The need to have two separate pieces of equipment produces the disadvantages of extra cost in purchasing the equipment and the necessity for extra storage space. Additionally known portable air compressors suitable for use as tyre inflators, due to their compact size, light weight and low cost can only use a small D.C. Electric Motor as a source of power. Such a small motor cannot produce both a high pressure and a high volume output at the same time.This means that an air compressor suitable for use as a tyre inflator having an output pressure which can reach 50 Ibs.

per sq. in. at a low output volume is not suitable for use in inflating a large article such as a rubber boat which requires a high volume - low pressure output because of the long time necessary to fill such a rubber boat.

There is thus a need for a combined air compressor and vacuum cleaner device which uses the same electric motor as a power source.

Additionally there is a general requirement for an air compressor which can be used both in a high pressure - low volume output and low pressure - high volume output manner.

According to the present invention there is provided a combined air compressor and vacuum cleaner device suitable for inflating a motor vehicle tyre or vacuum cleaning the vehicle interior, including an electric motor whose armature shaft carries a first clutch element at one end and a second clutch element at the other end, a twin piston and cylinder air compressor unit having a clutch element selectively releasably engageable by the first clutch element of the motor for actuation thereby, and a vacuum cleaner fan unit having a clutch element selectively releasably engageable by the second clutch element of the motor for rotatable actuation thereby, the motor being mounted for displacement, in response to selectively actuable control means, between a first drive position in which the first clutch element and air compressor unit clutch element are in driven engagement, with the second clutch element and fan unit clutch element disengaged, and a second drive position in which the second clutch element and fan unit clutch element are in driven engagement, with the first clutch element and compressor unit clutch element disengaged.

For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example to the accompanying drawings, in which: Figure 1 is a plan view from above of a combined air compressor and vacuum cleaner device according to one embodiment of the present invention, Figure 2 is an end view taken in the direction of the arrow A in Figure 1, Figure 3 is a side view taken in the direction of the arrow B of Figure 1, and Figure 4 is a part sectional view from above of an alternative compressor unit for use with the embodiment of Figures 1 to 3.

Turning now to the accompanying drawings a combined air compressor and vacuum cleaner device according to one embodiment of the invention is shown in Figure 1. This device is suitable for inflating a motor vehicle tyre or vacuum cleaning the vehicle interior. For inflating a motor vehicle tyre the device can be operated to provide a high output pressure - low output volume but it also can be operated to provide a low output pressure - high output volume for use in inflating larger articles such as a rubber boat.

The device according to the invention includes an electric motor 1 which prefereably is a twelve volt D.C. motor suitable for working from a motor vehicle electric battery. This motor 1 has an armature shaft 2 which carries a first clutch element 3 at one end and a second clutch element 4 at the other end. Preferably both these clutch elements and a further two clutch elements to be hereinafter described are in the form of mating dog clutches as shown although they can alternatively be any other form of clutch element such as a disc or cone friction clutch element The device also includes a twin piston and cylinder air compressor unit generally referenced 5 having a clutch element 6 selectively releasably engageable by the first clutch element 3 of the motor 1 for actuation thereby.A vacuum cleaner fan unit generally referenced 7 is provided which has a clutch element 8 selectively releasably engageable by the second clutch element 4 of the motor 1 for rotatable actuation thereby.

The motor 1 is mounted for displacement, in response to a selectively actuable control means, between a first drive position in which the first clutch element 3 and air compressor unit clutch element 6 are in driven engagement with the second clutch element 4 and fan element clutch element 8 disengaged and a second drive position in which the second clutch element 4 and the fan unit clutch element 8 are in driven engagement with the first clutch element 3 and compressor unit clutch element 6 disengaged. To this end the device includes a housing 9 with the motor 1 slidably mounted on two parallel spaced apart rails 10 fixedly attached to the housing 9, for displacement in the direction of the longitudinal axis of the motor shaft 2. The selectively actuable control means includes a lever 11 pivotally mounted at a pivot point 12 intermediate its ends on the housing 9.One end of the lever 11 is pivotally connected to the motor 1 and the other end of the lever is pivotally connected to a control rod 13. Movement of the control rod 13 in the direction of its longitudinal axis pivots the lever 11 and hence displaces the motor 1 one way or the other along the rails 10.

Preferably resilient means, not shown, are provided for biasing the motor 1 towards one of the first and second drive positions. Such a resilient means conveniently is a coil compression spring located to bias the motor 1 into the first drive position.

The compressor unit 5 includes two end to end spaced apart piston and cylinder assemblies 14 and 15 whose piston rods 16 and 17 respectively are reciprocately connected to the compressor unit clutch element 6 via a gear and crank system operative to convert rotary movement of the compressor unit clutch element 6 into reciprocatory movement of the pistons.

The piston and cylinder assembly 14 is a low pressure assembly and the piston and cylinder assembly 15 is a high pressure assembly. The output side of the low pressure assembly 14 is connected via a non return outlet valve 18 to the output side of the high pressure assembly 15 via a length of connecting pipe 19. The non return outlet valve 18 has a one direction gate provided preferably by a simple spring leaf. A further non return output valve conveniently is provided on the output side of the high pressure assembly 15 which in turn communicates with a connector 20 for connection to an article to be supplied with air under pressure. Conveniently the cylinder and piston of the high pressure assembly 15 are smaller than the cylinder and piston of the low pressure assembly 14.

The piston rods 16 and 17 are connected to a crank shaft 21 of-the gear and crank system in a manner such as to be pivotal on the crank shaft when the latter is moved about a pivotal axis other than its longitudinal axis. To this end the crank shaft 21 is eccentrically mounted on a crank disc 22 attached to one end of a shaft 23 rotatably journalled on the housing 9 with a gear 24 being fixedly provided on the other end of the shaft 23.

This gear 24 meshes with a further gear 25 fixedly mounted on the shaft carrying the clutch element 6. In this way rotary movement of the clutch element 6 is converted via the gears 24 and 25 and the crank disc 22 and crank shaft 21 into reciprocating motion of the piston rods 1 6 and 1 7.

The cylinder of the low pressure assembly 14 includes a variable pressure relief valve 26 having a control nut 27 operable to vent the output side of the cylinder of the pressure assembly 14 of atmosphere via a vent 28. The pressure relief valve 26 is in the form of a cylinder containing a piston (not shown) slidingly mounted therein on a pin resiliently urged by a spring located against the control nut 27. By screwing the control nut in or out it is possible to adjust the force supplied by the spring to the piston in the cylinder of the relief valve 26. In this way the relief valve 26 can be set to operate at a pressure in excess of any desired pressure so that at excess pressures the piston in the cylinder of the valve 26 is displaced against the spring to uncover the vent 28 thereby venting the cylinder of the low pressure assembly 14 to atmosphere.In this event the low pressure assembly being connected directly to atmosphere does not take significant power from the motor 1 which mainly drives the high pressure assembly 15 thereby producing high pressure - low output. Due to the small size of the cylinder of the high pressure assembly 15 the power required to drive this assembly to produce the high pressure - low output necessary for inflating a vehicle tyre will not exceed the maximum output of the motor 1.

On the contrary when a low pressure - high output is required to fill, for example, a rubber boat the output of compressed air comes from both the low and high pressure assemblies 14 and 15 via the connector 20. In this way with both assemblies 14 and 15 supplying compressed air it is possible considerably to shorten the period required for filling the article such as a rubber boat.

The vacuum cleaner fan unit 7 includes a fan 29 rotatably mounted on the housing 9 for cooperation with ducting (not shown) to provide a suction effect for the vacuum cleaner fan unit.

In order to operate the fan unit 7 it is merely necessary to depress the control rod 13 against the spring pressure not shown so as to move the motor 1 from the first drive position in which the clutch elements 3 and 6 are engaged into the second drive position in which the clutch elements 4 and 8 are engaged to rotate the fan 29 when the motor 1 is energised. Means are provided for locking the control rod 13 in the position such that the clutch elements 4 and 8 are engaged and the clutch elements 3 and 6 are disengaged.

Releasing the control rod 13 allows the motor 1 to return to the first drive position under the action of the spring (not shown) so that the clutch elements 3 and 6 are engaged and the clutch elements 4 and 8 are disengaged. In this first drive position the compressor unit 5 is operative when the motor t is energised.

Any form and shape of casing may be employed to enclose the device of the invention and provide the desired ducting for the vacuum cleaner fan unit 7. Additionally the units 5 and 7 may be connected in any convenient manner by any convenient means to an article to be inflated or to accessories providing a brush or other heads for the vacuum cleaner fan unit 7.

Alternatively, as shown in Figure 4, the compressor unit of the embodiments of Figures 1 to 3 can be modified by the provision of a different low pressure assembly and a different variable pressure relief valve for the low pressure assembly. In this embodiment, which can be used with the fan unit 7 and motor 1 of the embodiment of Figures 1 to 3, like parts will be given like reference numerals. As shown in Figure 4 this embodiment does not employ a low pressure piston and cylinder assembly 14 as in the previous embodiment but employs a low pressure diaphragm and chamber assembly generally indicated at 30.

This low pressure diaphram and chamber assembly has a connecting rod 31 rotatively mounted at one end on the crankshaft 21 as in the previous embodiment. The other end of the connecting rod 31 is attached in any convenient manner to a resilient diaphragm 32, preferably made from rubber. Preferably the diaphragm is made from sheet rubber and has a circular outline with the connecting rod 31 secured to the central region thereof. The peripheral region of the diaphragm 32 is secured in any convenient manner, such as by clamping, to a low pressure housing part 33 to form therewith a low pressure variable volume chamber 34, one wall of which is formed by the diaphragm 32.The low pressure diaphragm and chamber assembly 5 is arranged end to end with the high pressure piston and cylinder assembly 1 5 and spaced apart therefrom with the piston rod 17 and connecting rod 31 being reciprocably movable by drive applied from the motor 1 to the shaft 23.

Reciprocal movement of the connecting rod 31 in turn causes a pumping movement of the diaphragm 32 to draw inlet air into the chamber 34 through a nonreturn valve on movement of the connecting rod 31 away from the housing 33 and to compress this air in the chamber 34 against the action of the non return valve on return of the connecting rod towards the housing part 33.

An outlet side 35 of the chamber 34 is connected in any convenient manner such as by a flexible tube 36 to a variable pressure relief valve assembly generally indicated at 37. This pressure relief valve 37 has the form of at least two, and preferably three, interfitting open-end axially bored vent cylinders. The flexible tube 36 leading from the chamber 34 is connected to one open end 38 of a first vent cylinder 39. This vent cylinder 39 has at least one lateral vent port 40 therethrough and is slidably fitted at its other open end 41 in a second open-ended axially bored vent cylinder 42. This second vent cylinder thus is slidably mounted on the outer surface of the first vent cylinder 39 and also is provided with at least one lateral vent port 43 therethrough.

The second vent cylinder 42 thus is slidably mounted on the exterior of the first vent cylinder 39 and is resiliently biased by a spring 44 in a direction away from the first vent cylinder 39 to a rest position to the right of Figure 4 in which the two lateral ports 40 and 43 are out of register with one another. To this end the first vent cylinder 39 is provided with a laterally upstanding shoulder 45 towards the open end 38 thereof against which one end of the spring 44, located around the vent cylinder 39, bears. The other end of the spring 44 bears against an end face 46 of the open end of the second vent cylinder 42 slidably fitting over the first vent cylinder 39.At its other open end 47 the second vent cylinder 42 has a reduced internal diameter to provide a shoulder for bearing against the end 41 of the first vent cylinder 39 at the innermost limit of travel of the second vent cylinder 42. The other open end 47 of the second vent cylinder 42 carries the non return output valve 18.

The first and second vent cylinders 39 and 42 are operative to function as the variable pressure relief valve 26 of the first embodiment such that excess pressure at the output side of the non return output valve 18 closes the latter and displaces the second vent cylinder 42, against the resilient bias of the spring 44, towards the open end 38 of the first vent cylinder until the two vent ports 40 and 43 come into registry to vent the output side of the low pressure assembly 5 to atmosphere until removal of the excess pressure on the output side of the non return output valve 18 allows the second cylinder 42 to return, under the resilient bias force of the spring 44, to the rest position.

The first and second vent cylinders 39 and 42 are mounted within a third vent cylinder 48. This third vent cylinder is fixedly mounted and is also axially bored and provided with a vent port 49 opening laterally therethrough this third vent cylinder 48 is fixedly mounted and provides a bearing surface within which the second vent cylinder 42 is slidably mounted over the first vent cylinder 39. The vent ports 40 and 49 are aligned in registry and the vent port 43 in the second vent cylinder 42 when in registry with the vent port 40 is also in registry with the vent port 49 to vent excess pressure from inside the first cylinder 39 to atmosphere. In order to provide for effective sealing between the second and third vent cylinders 42 and 48 a resilient seal such as an O-ring 50 is provided on the outside of the second vent cylinder 42 to bear against a shoulder 51 at the end 47 thereof.This O-ring 50 provides a seal between the second vent cylinder 42 and the third vent cylinder 44 and is arranged to bear against an inner shoulder 52 at the innermost position of the second vent cylinder 42 corresponding to registry of the three vent ports.

Conveniently an end cap 53 is screw threadably engaged on the outermost end of the third vent cylinder 48 to close off the latter. This end cap is removable to afford access to the second and first vent cylinders 42 and 39 for maintenance purposes. Additionally the end cap 53 advantageously is provided with a screw adjustment means 54 bearing against an end closure 55 on the second vent cylinder 42 whereby the variable displacement of the second vent cylinder 42 can be adjusted. The second vent cylinder 42 is provided, adjacent the end closure 55 with an outlet aperture 56 which communicates with the connector 20 downstream of the non return valve 18.

This connector 20 also communicates, via a side stub 57 and a flexible connecting pipe 58 with the output side of the high pressure piston and cylinder assembly 15. Thus the variable pressure relief valve 37 of the embodiment of Figure 4 operates in the same manner as that of the embodiment of Figures 1 to 3 to vent the low pressure assembly 30 to atmosphere in situations where the high pressure assembly 15 dominates in order to reduce the power consumption of the motor 1. In the embodiment shown in Figure 4 the air inlet 58 to the chamber 34 is provided with a filter 59 and a non return valve 60. Similarly the output side of the high pressure piston and cylinder assembly 15 is provided with a non return valve 61.

Claims

1. A combined air compressor and vacuum cleaner device suitable for inflating a motor vehicle tyre or vacuum cleaning the vehicle interior, including an electric motor whose armature shaft carries a first clutch element at one end and a second clutch element at the other end, a twin piston and cylinder air compressor unit having a clutch element selectively releasably engageable by the first clutch element of the motor for actuation thereby, and a vacuum cleaner fan unit having a clutch element selectively releasably engageable by the second clutch element of the motor for rotatable actuation thereby, the motor being mounted for displacement, in response to selectively actuable control means, betweeen a first drive position in which the first clutch element and air compressor unit clutch element are in driven engagement, with the second clutch element and fan unit clutch element disengaged, and a second drive position in which the second clutch element and fan unit clutch element are in driven engagement, with the first clutch element and compressor unit clutch element disengaged.

2. A device according to claim 1, including a housing with the motor slidably mounted on two parallel spaced apart rails, fixedly attached to the housing, for displacement in the direction of the longitudinal axis of the motor shaft.

3. A device according to claim 2, wherein the control means includes a lever pivotally mounted intermediate its ends on the housing, with one end of the lever being pivotally connected to the motor and the other end of the lever being pivotally connected to a control rod, so that movement of the control rod in the direction of its longitudinal axis pivots the lever and hence displaces the motor one way or the other along the rails.

4. A device according to any one of claims 1 to 3, including resilient means for biasing the motor towards one of the first and second drive positions.

5. A device according to claim 4, wherein the resilient means is a coil compression spring located to bias the motor into the first drive position.

6. A device according to any one of claims 1 to 5, wherein the clutch elements are dog clutch elements.

7. A device according to any one of claims 1 to 6, wherein the compressor unit includes two end to end spaced apart piston and cylinder assemblies whose piston rods are reciprocally connected to the compressor unit clutch element via a gear and crank system operative to convert rotary movement of the compressor unit clutch element into reciprocatory movement of the pistons.

8. A device according to claim 7, wherein one piston and cylinder assembly is a low pressure assembly and the other piston and cylinder assembly is a high pressure assembly, with the output side of the low pressure assembly being connected to the output side of the high pressure assembly which in turn communicates with a connector for connection to an article to be supplied with air under pressure.

9. A device according to any one of claims 1 to 6, wherein the compressor unit includes a high pressure piston and cylinder assembly with a piston rod and a low pressure resilient diaphragm and chamber assembly with a connecting rod attached to the diaphragm, the two assemblies being arranged end to end and spaced apart with the piston rod and connecting rod being reciprocally connected to the compressor unit clutch element via a gear and crank system operative to convert rotary movement of the compressor unit clutch element into reciprocatory movement of the piston and diaphragm.

10. A device according to claim 8 or claim 9, including a non return valve in the air connection between the low and high pressure assemblies.

11. A device according to claim 10 in which the non return output valve is on the low pressure assembly and a further non return output valve is provided on the high pressure assembly.

12. A device according to any one of claims 8 to 11, including a variable pressure relief valve operable to vent the output side of the cylinder or chamber of the low pressure assembly to atmosphere.

13. A device according to claim 12 in which the output side of the low pressure assembly chamber is connected to one open end of a first open ended axially bored vent cylinder having at least one lateral vent port therethrough, a second openended axially bored vent cylinder slidably fitting, via one open end thereof, on and over the other open end of the first vent cylinder, which second vent cylinder also has at least one lateral vent port therethrough, is resiliently biased in a direction away from the first vent cylinder to a rest position in which the two lateral ports are out of register with one another, and carries at its other open end the non return output valve, the first and second vent cylinders being operative to function as the variable pressure relief valve such that excess pressure at the output side of the non return output valve closes the latter and displaces the second vent cylinder, against the resilient bias, towards the one open end of the first vent cylinder until the two vent ports come into registry to vent the output side of the low pressure assembly to atmosphere until removal of the excess pressure at the output side of the non return output valve allows the second vent cylinder to return, under the resilient bias force, to the rest position.

14. A device according to any one of claims 3 to 13, when appended to claim 2, wherein the vacuum cleaner fan unit includes a fan rotatably mounted on the housing for co-operation with ducting to provide a suction effect for the vacuum cleaner fan unit.

15. A combined air compressor and vacuum cleaner device substantially as hereinbefore described with reference to the accompanying drawings.