GB2091850A

GB2091850A - Foot operated air supply valve assembly

Info

Publication number: GB2091850A
Application number: GB8137231A
Authority: GB
Original assignee: USHIO AIR TOOL; USHIO AIR TOOL CO Ltd
Current assignee: USHIO AIR TOOL; USHIO AIR TOOL CO Ltd
Priority date: 1981-01-23
Filing date: 1981-12-10
Publication date: 1982-08-04
Also published as: GB2091850B; JPS6021270B2; KR890000431B1; KR830008088A; JPS57124182A

Abstract

An improved air supply valve assembly is provided, which is located in an air supply system passage connecting a compressed air supply source such as a compressor or the like to a pneumatic motor, air cylinder or the like and adapted to supply compressed air to the pneumatic apparatus through an air supply port of a valve mechanism provided on a base plate, which is caused to open the air supply port by tilting from any angular portion a foot plate by the foot of an operator. <IMAGE>

Description

SPECIFICATION Foot operated air supply valve assembly This invention relates to a foot-operated air supply valve assembly.

In a prior art foot-operated valve assembly, a foot plate which is substantially rectangular as viewed in a plan view is used, whose one end is pivotally mounted in the form of a cantilever on a base plate so as to be vertically rockable through elastic means such as a spring or the like. A valve mechanism arranged under the foot plate is caused to open the valve assembly by depressing the foot plate by a foot.

With such a prior art construction, however, a position where the foot plate is depressed is limited in one direction on the free end side of the foot plate, so that when the foot plate is pressed at its pivotal end, valve opening operation cannot be achieved. As a result, the position of an operator holding a pneumatic apparatus as a pneumatic motor, air cylinder or the like for its operation is limited so as to restrain the operator in a particular position, whereby the operation is made different.

This invention relates to a foot-operated air supply valve assembly and in more detail to an improved air supply for location in an air supply system passage connecting a compressed air supply source such as a compressor or the like to a pneumatic apparatus such as a pneumatic motor, air cylinder or the like, and adapted to supply compressed air to the pneumatic apparatus through an air supply port of a valve mechanism, which is caused to open the air supply port by depressing a foot plate by a foot of an operator.

It is an object of at least the preferred embodiment of the invention to provide a valve assembly which eliminates the disadvantage of the prior art, and which enables an operator to perform the valve opening operation in any direction without limiting the direction of the depressing position of a foot plate, thereby making easy an operation using a pneumatic apparatus.

It is another object of the preferred embodiment of the invention to provide an air supply valve assembly which is functional and small in construction and which effectively utilize a space between a foot plate and a base plate to form a silencer chamber into which exhaust air from a pneumatic apparatus is introduced and caused to flow out of the silencer chamber after being silenced.

According to the invention there is provided, in a first aspect a foot operated air supply valve assembly including a valve mechanism mounted on a base and including afoot engaging member tilting of which by the foot causes opening of the valve, said member being arranged so that it can be tilted by the foot from any of a plurality of angularly spaced positions.

The invention also provides a foot-operated air supply valve assembly including a valve mechanism on a base plate, which performs valve opening operation by depressing a foot plate by a foot of an operator, wherein said foot plate is formed disklike and its inner surface at a center is arranged on and connected to said valve mechanism.

The invention further provides an air supply valve assembly including a valve mechanism on a base plate, which performs valve opening operation by depressing a foot plate by a foot of an operator, wherein said foot plate is formed disklike whose inner surface at a center is arranged on said valve mechanism, and a silencing material having an elasticity is interposed between said foot plate and said base plate to form around said valve mechanism a silencer chamber, into which exhaust air flowing out of a pneumatic apparatus connected through an air hose to an air supply port of said valve mechanism is caused to flow.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a plan view, partially cut away, of a valve assembly, according to an embodiment of the invention; Figure2 is a sectional view taken along lines ll-ll in Figure 1; and Figures 3 and 4 are sectional views taken along positions of an inlet pipe and an air supply pipe of the valve assembly, respectively, of which Figure 3 illustrates an open position of the valve assembly caused by depressing the foot plate at its center portion, and of which Figure 4 shows an open position of the assembly caused by depressing the plate at the peripheral point.

One embodiment of the present invention will be explained with reference to the attached drawings.

In Figures 1 and 2, reference numerals (1), (10) and (30) illustrate a base plate, a valve mechanism and a foot plate, respectively.

The base plate (1) has a center portion which is cut and raised by pressing into an annular and angleshaped cross-sectional form (r). A bottom plate (2) is attached and fixed to a bottom of the annular angle-shaped cross-sectional center portion to form a support portion (3) for the valve mechanism (10), within which a coil spring (4) and a support plate (5) are mounted.

The bottom plate (2) is formed at its center with a concaved shaft end support (6) and in its circumference with an annular groove (7) within which the bottom end of the spring (4) is seated.

The support plate (5) is formed substantially of omega cross-section having at its outer periphery a flange (5') and is fitted with the support portion (3) such that the flange (5') is located under an engaging edge (3') formed on an upper surface of the support portion (3). The spring (4) is arranged under the support plate (5).

The spring (4) normally urges the support plate (5) upwardly to cause the flange (5') to abut against the engaging edge (3') of the support portion (3).

Accordingly, the support plate (5) is upwardly and downwardly resiliently movably supported by the spring (4).

The support (5) is formed at its center with a support opening (8) within which is fitted and supported a cylinder (11) of the valve mechanism (10).

The bottom plate (2) is formed with a leak aperture (9) in the shaft end support (6).

The valve mechanism (10) comprises the cylinder (11), a plunger (12) and a valve body (13). The cylinder (11) has therein a bore formed at its upper portion with a valve seat (14) on which is arranged the valve body (13) upwardly and downwardly movable in the bore to close and a spring (15) is arranged on and abuts against the valve body (13) to normally urge it resiliently downwardly against the valve seat (14) so as to close the valve opening (14').

The plunger (12) is closely slidably inserted in the bore of the cylinder (11) below the valve seat (14). A spring (16) is interposed between the plunger (12) and the valve seat (14) to urge the plunger (12) downwardly.

The plunger (12) has a lower end substantially in the form of a hemisphere which extends somewhat beyond the lower end of the cylinder (11) and has a reduced-diameter upper end which is less in diameterthan the valve opening (14') so as to extend therethrough in its one operative position and is in opposition to the underside of the valve body (13) with a slight clearance in the normal position.

The plunger (12) is formed with a vertical throughhole (17) adapted to communicate with the leak aperture (9) of the bottom plate (2).

The cylinder (11) is provided on its outer circum ferencewith an inlet pipe (18) forming a fluid entrance and an air supply pipe (19) forming an air supply port, both pipes extending from the cylinder (11). The inlet pipe (18) communicates with the inside of the cylinder (11) at the location above the valve seat (14), while the air supply pipe (19) communicates with the inside of the cylinder (11) below the valve seat (14), (Figure 3).

Moreover, the cylinder (11) is formed in its lower circumferential portion with a shoulder (20) by reducing the diameter thereat and on the upper outer periphery with a lug (21) extending outwardly to which the foot plate (30) is secured by means of set screws (22).

The lower end of the cylinder (11) of the valve mechanism (10) is inserted into the support opening (8) of the support plate (5) supported in the support portion (3) to seat the shoulder on the support plate (5) so as to uprightly stand the cylinder (11) on the support plate (5). The lower end of the plunger (12) is pivotally supported by the shaft end support (6) of the bottom plate (2) to hold the plunger (12) on the base plate (1).

To the inlet pipe (18) of the valve mechanism is connected an air hose (23) connected to a compressed air supply source (not shown) such as a compressor. To the air supply pipe (19) is connected a hose (25) to be jointed to a pneumatic apparatus (24) such as a grinder with a pneumatic motor.

The foot plate (3) is of inverted disc shape, and in the embodiment shown in the drawings has a cross-section comprising a flat surface (31) at the center, an inclined surface (32) about its outer periphery and a peripheral wall (33) vertically depending from the outer edge of the inclined surface (32).

The peripheral wall (33) is formed with apertures (34) and (35) for passing therethrough the hoses (23) and (25) for the inlet and air supply pipes.

The foot plate (30) is arranged with the inner surface of the flat surface (31) on the upper end surface of the cylinder (11) of the valve mechanism (10) and fixed to the lug (21) of the cylinder (11) by means of the set screws (22) to cover the valve mechanism (10).

In this case, the foot plate (30) is so located relative to the base plate as to provide a clearance (a) between the baseplate and the lower end of the peripheral wall (33) of the foot plate (30), which enables the foot plate to be vertically moved and rocked by depressing it by a foot of an operator. A silencing material (36) having an elasticity such as sponge is annularly interposed between the base plate (1) and the lower inner surface of the inclined surface of the foot plate to form a silencer chamber (37) surrounded by the silencing material (36) under the foot plate (30).

The hose (25) for air supply is of a double tube construction whose inner passage (38) is connected to the air supply pipe (19) to supply compressed air through the inner passage to the pneumatic apparatus (24) and whose outer passage (39) has one end communicating with the silencer chamber (37) to introduce the exhaust air from the pneumatic apparatus (24) through the outer passage (39) into the silencer chamber (37).

With the valve assembly constructed as above described, when the foot plate (30) is depressed with its flat surface (31) at the center, the cylinder (11) of the valve mechanism (10) is lowered downwardly along the plunger (12), so that the valve body (13) abuts against the upper end of the plunger (12) which is stationary and is then pushed upwardly away from the valve seat (14) to open the valve opening (14') (Figure 3).

Therefore, the compressed air flowing through the inlet pipe (18) into the cylinder (11) passes through the valve opening (14') into the air supply pipe (19) and through the inner passage (38) of the hose (25) into the pneumatic apparatus (24) to actuate it.

When the foot plate is released, the cylinder (11) is returned upwardly by the support plate (5) with the aid of the spring forces of the springs (4) and (16), and the valve body (13) is restored into its closed position by the spring force of the spring (15) to close the valve opening (14') automatically.

Even if the foot plate (3) is depressed at any point of the periphery of the inclined surface (32), the cylinder (11) is moved downwardly along the plunger (12) although they are inclined, so that the opening operation of the valve assembly is achieved to supply the air to the pneumatic apparatus (24) in the same manner as above described (Figure 4). The opening of the valve opening (14') depends upon the depressed distance of the foot plate (30), so that the amount of air supply can be finely adjusted.

The compressed air used to operate the pneumatic apparatus (24) is introduced through the outer passage (39) of the hose (25) into the silencer chamber (37) from which the air flows through the silencing material (36) and the clearance (a) during which the air is silenced.

In the closed position of the valve assembly shown in Figure 1, if the close contact between the valve body (13) and the valve seat (14) fails for some reasons and thus the compressed air flows through the valve opening (14') into the cylinder (11), the air is exhausted through the through-hole (17) of the plunger (12) and the leak aperture (9), so that an extraodinary pressure rise in the cylinder (11) can be prevented effectively for safety.

In the open positions of the valve assembly shown in Figures 3 and 4, the upper end surface of the plunger (12) is kept to abut against the underside of the valve body so as to close the through-hole )17) thereby preventing the compressed air from leaking through the hole (17).

Although the foot-plate (30) in the above embodiment is disklike, it is not limited thereto but may be modified at will.

According to the embodiment of the invention, a the foot according to the embodiment of the invention, a the foot plate is formed disklike and its inner surface at the center is arranged on and connected to the valve mechanism as above described, even if the foot plate is depressed at its any point, a positive valve opening operation can be effected and therefore the direction of foot depressing operation is not critical, which is different from the pror art, so that the valve assembly according to the embodiment of the invention enables an operator to actuate a pneumatic apparatus in any position and posture which improves ease in operation.

According to another aspect of the embodiment of the invention, the silencing material having an elasticity is interposed between the foot plate and the base plate to form a silencer chamber into which exhaust air flowing from a pneumatic apparatus is introduced and then exhausted through the silencing material, so that the valve assembly can silence the exhaust air from the pneumatic apparatus near the valve assembly which is, therefore, superior in environmental sanitation, and is functional and small in construction.

Accordingly, the valve assembly according to the embodiment of the invention can achieve the objects of the invention.

Claims

1. A foot operated air supply valve assembly including a valve mechanism mounted on a base and including a foot engaging member tilting of which by the foot causes opening of the valve, said member being arranged so that it can be tilted by the foot from any of a plurality of angularly spaced positions.

2. An assembly according to claim 1, wherein the foot engaging member is a disc having its centre operatively connected to said valve, the disc being tiltable from any angular position relative to the disc centre.

3. An assembly according to Claim 1 or 2, wherein there is an elastic silencing material between the base and foot engaging member to form a silencing chamber around the valve, and there is an inlet for air exhausted from a pneumatically operated apparatus to enable such air to be charged into the silencing chamber and dissipated to atmosphere through said silencing chamber.

4. An assembly according to Claim 3, wherein said inlet is the outer passage of a double tube of which the inner passage forms an outlet from the valve assembly.

5. An assembly according to any preceding claim, wherein the valve assembly comprises a plunger and a cylinder in which the plunger slides, the plunger and cylinder being arranged to extend upright when the assembly is in use.

6. An assembly according to claim 5, wherein the plunger has a rounded lower end which engages a recess in the base to enable the plunger and cylinder to slide relatively to open the valve even if the plunger and cylinder are tilted as occurs when the foot engaging member is tilted.

7. An assembly according to any preceding claim, wherein spring means urges the foot engaging member to a quiescent position in which the valve is closed when foot pressure is removed.

8. Afoot-operated air supply valve assembly including a valve mechanism on a base plate, which performs valve opening operation by depressing a foot plate by a foot of an operator, wherein said foot plate is formed disklike and its inner surface at a center is arranged on and connected to said valve mechanism.

9. An air supply valve assembly including a valve mechanism on a base plate, which performs valve opening operation by depressing a foot plate by a foot of an operator, wherein said foot plate is formed disklike whose inner surface at a center is arranged on said valve mechanism, and a silencing material having an elasticity is interposed between said foot plate and said base plate to form around said valve mechanism a silencer chamber, into which exhaust air flowing out of a pneumatic apparatus connected through an air hose to an air supply port of said valve mechanism is caused to flow.

10. An air supply valve assembly as set forth in claim 2, wherein said air hose is of a double tube construction having an outer passage through which said exhuast air from said pneumatic apparatus flows into said silencer chamber.

11. A foot-operated air supply valve assembly substantially as hereinbefore described with reference to the accompanying drawings.