GB2313173A

GB2313173A - Pneumatic control valve

Info

Publication number: GB2313173A
Application number: GB9610254A
Authority: GB
Inventors: Ove Per Pilskar
Original assignee: Emhart Glass Machinery Investments Inc
Current assignee: Emhart Glass Machinery Investments Inc
Priority date: 1996-05-16
Filing date: 1996-05-16
Publication date: 1997-11-19
Also published as: GB9610254D0

Abstract

A valve which can be used to control the rate of flow of operating air into a supply passage and of exhaust air out of the supply passage and to exhaust from a pneumatically operated mechanism, comprises a plunger 50 which is adjustable to determine the restriction on the flow of air into the supply passage 10, and is movable against spring pressure so as not to restrict the flow of air from the supply passage to exhaust 12, and an adjustable sleeve 28 which determines the restriction on the flow of air to exhaust. Sleeve 28 is mounted for axial adjustment in supporting housing 16. A supply control sleeve 38 is mounted for axial adjustment in sleeve 28. Adjustment of plunger 50 is by means of screw 64 acting on helical spring 66 within sleeve 38.

Description

PNHUXATIC CONTROL VALVE This invention is concerned with pneumatic control valves.

In glass machines, particularly the well known I.S.

machine, there are a number of individually operated pneumatic mechanisms, and to operate such mechanisms firstly at an appropriate time a supply of compressed air, at a controlled pressure, must be provided and secondly, again at the appropriate time, air must be exhausted, under controlled conditions, from the mechanism.

The control of such supply and exhaust to the various mechanisms is usually provided by use of a valve block which comprises a number of valves for controlling the supply of air to the mechanism, conventionally an on/off valve for controlling the supply of operating air to the mechanism and for connecting such air to exhaust, and separate restrictor valves to control the rate of supply of operating air to the mechanism and the rate at which air can exhaust. The number of valves leads to both complexity and expense of the valve block.

It is one of the objects of the present invention to provide a single valve adapted independently to control the rate of flow of operating air into a supply passage and of exhaust air out of the supply passage to exhaust from a pneumatically operated mechanism.

The present invention provides a valve adapted independently to control the rate of flow of operating air into a supply passage and of exhaust air out of the supply passage and to exhaust from a pneumatically operated mechanism, comprising a supporting housing adapted to position the valve in a valve block and comprising a tubular portion having an axial bore with transverse apertures, an exhaust sleeve mounted for axial adjustment in the supporting housing, and having an end portion which projects into the bore of the supporting housing, a supply control sleeve mounted for axial adjustment in the exhaust sleeve, a valve plunger mounted for axial movement in the control sleeve against adjustable spring pressure and projecting through the end portion of the exhaust sleeve, a head on the valve plunger an extension member connected to the supporting housing comprising an axial bore in which the head is slidably mounted and a transverse opening leading to the bore wherein in use of the valve the supporting housing extends across the exhaust passage in a valve block and the extension member extends across the supply passage, and adjustment of the position of the supply control sleeve adjusts the position of the head of the plunger thus to control the rate of flow of air into the supply passage, the head can move against spring pressure so that it does not restrict the flow of air from the supply passage to exhaust, and adjustment of the exhaust sleeve adjusts the positioning of the exhaust sleeve in the bore of the supporting housing thus to control the rate of flow of air to exhaust.

There now follows a description, to be read with reference to the accompanying drawings, of a valve embodying the invention.

In the drawings: Figure 1 shows, generally in section, a valve embodying the invention installed in a valve block of a glass container manufacturing machine.

Figure 2 shows, in perspective, a supporting housing and a forward extension of the valve.

A valve block 2 (shown diagrammatically in section) comprises an inlet passage 4 connected to a supply of compressed air and which leads through a manifold 6 into a chamber 8 and thence to a supply passage 10, and an exhaust passage 12 which is connected via the chamber 8 to the supply passage 10. The supply passage 10 is connected to a pneumatically operated mechanism.

A valve 14 is positioned in the valve block 2 and serves to control the rate of flow of air from the inlet passage 4 into the supply passage 10, and independently the rate of flow of air from the supply passage 10 out through the exhaust passage 12.

The valve 14 comprises a supporting housing 16 (see Figure 2) adapted to position the valve 14 in the valve block 2. The housing 16 comprises a body 15 which is generally cylindrical with flattened sides and comprises an axial threaded bore 26, and a tubular portion 18 having an axial bore 17 of somewhat smaller diameter than the bore 26.

Diametrically opposed apertures 19 are provided in the tubular portion 18, which also comprises an end ring portion 20 having a bore of somewhat less diameter than the bore 17.

The housing 16 comprises two opposed outwardly extending flanges 21 provided with bores 23 by which the housing 16 may be secured to a wall 22 of the valve block 2. Threaded into the bore 26 for axial adjustment relative to the housing 16 is an exhaust sleeve 28 which comprises towards one end a smooth bore 30, which terminates in an end portion 32 having a central hole 34 provided in it, and towards the other end a threaded bore 36 of slightly greater diameter than the bore 30. The end portion 32 projects forwardly from the outer housing 16 into the bore 17 of the housing 16, and lies between the apertures 19, closing them off to some extent.

Threaded into the bore 36 for axial adjustment relative to the exhaust sleeve 28 is a supply control sleeve 38 which comprises an axial bore 40 having a threaded end portion 42 adjacent a head 44. Remote from the head 44 is an end portion 46 provided with a narrow central bore 48.

A forward extension member 68 of the valve 14 (see Figure 2) comprises a tubular rod portion 70 and a cylindrical portion 72 which meet a circular seating wall 74. The rod portion 70 has an axial bore 76 which leads through the wall 74 to a larger bore 78 of the portion 72.

The cylindrical portion 72 is open ended, and the end portion of the portion 72 comprises a seating ring 80. A transverse opening 82 in the portion 72 leads transversely into the bore 78.

The extension member 68 is assembled with the supporting housing 16, with the wall 74 abutting against an end face of the ring portion 20, and a pin 84 in said end face locating in a hole 86 in the wall 74 and preventing rotation of the extension member 68 with respect to the housing 16. The rod portion 70 extends through the hole 34 in the end portion 32 and into the bore 48 in the end portion 46.

A valve plunger 50 is mounted for axial movement in the supply control sleeve 38 and comprises a cylindrical stem 52 which at one end has secured to it by a nut 60 a head 58, and at the other end is provided with a stop head 62. The head 62 is a sliding fit in the bore 40, and the stem 52 is a sliding fit in bore 76 of the rod portion 72.

A stop screw 64 is threaded into the threaded end portion 42 of the bore 40 of the supply control sleeve 38 and bears on a helical spring 66 which acts between the screw 64 and the stop head 62 of the plunger 50. The pressure exerted by the spring 66 is adjustable by adjustment of the screw 64.

The head 58 is a sliding fit in the bore 78 and is adapted to seat seating against the seating ring 80.

In a rest position of the valve 14 the spring 66 brings the head 58 into contact with the ring 80.

In the use of the valve 14 it is positioned in the valve block 2 which is so dimensioned that the supply passage 10 leads to the seating ring 80, and thence through the bore 78 and the opening 82 to a portion of the supply passage which leads to the chamber 8. Similarly, the supporting housing 16 is so positioned that the apertures 19,19 are aligned with the exhaust passage 12.

At an appropriate stage in the operation of the machine in which the valve block 2 is used, air is required to pass in through the inlet passage 4 and out through the supply passage 10 to a pneumatically operated mechanism, and it is necessary to be able to restrict the flow of such air to a desired level. Viewing the figure, the supply control sleeve 38 can be rotated so that it moves outwardly from the housing 20 and, because of the engagement of the stop head 62 of the valve plunger 50 with the end portion 46, the head 58 is moved away from the seating ring 80 to provide a gap providing the desired restriction of the air flow. When at a later stage in the operation of the machine the supply of air through the inlet passage 4 ceases and it is required to exhaust air from the mechanism, the air to be exhausted passes in through the supply passage 10 and exerts pressure on the head 58, pushing the valve plunger back against the force of the spring 66 and thus ensuring that the head 58 provides no effective restriction to the exhaustion of the air. Any restriction of the exhaustion of the air may be provided by the end portion of the exhaust sleeve 28 which extends into the exhaust passage 12 and may be screwed in and out to provide the desired degree of restriction of the exhaustion of the air.

Claims

1 A valve adapted independently to control the rate of flow of operating air into a supply passage and of exhaust air out of the supply passage and to exhaust from a pneumatically operated mechanism, comprising a supporting housing (11) adapted to position the valve in a valve block and comprising a tubular portion (18) having an axial bore (17) with transverse apertures, an exhaust sleeve (28) mounted for axial adjustment in the supporting housing (16), and having an end portion (32) which projects into the bore (17) of the supporting housing (16), a supply control sleeve (38) mounted for axial adjustment in the exhaust sleeve (28), a valve plunger (50) mounted for axial movement in the control sleeve (38) against adjustable spring pressure and projecting through the end portion (32) of the exhaust sleeve (28), a head (58) on the valve plunger an extension member (68) connected to the supporting housing (16) comprising an axial bore (78) in which the head (58) is slidably mounted and a transverse opening leading to the bore (78) wherein in use of the valve the supporting housing (16) extends across the exhaust passage in a valve block and the extension member (68) extends across the supply passage, and adjustment of the position of the supply control sleeve adjusts the position of the head (58) of the plunger thus to control the rate of flow of air into the supply passage, the head (58) can move against spring pressure so that it does not restrict the flow of air from the supply passage to exhaust, and adjustment of the exhaust sleeve (28) adjusts the position of the exhaust sleeve (28) in the bore (17) thus to control the rate of flow of air to exhaust.

2 A valve according to claim 1 wherein the exhaust sleeve (28) is screw threaded into the supporting housing (16) and the supply control sleeve (38) is screw threaded into the exhaust sleeve (28).

3 A valve according to claim 1 wherein the adjustable spring pressure is provided by a helical spring (66) in a bore (49) of the supply control sleeve (38) acting between the valve plunger (50) and a stop screw threaded into the bore (40).