US2349548A - Pneumatic timing device - Google Patents

Description

May 23, 1944,

A. H. HABERSTUMP PNEUMATIC TIMING DEVICE Filed April 15, 1942 May 23, 19

PNIUIL'I'IC mo osvroa Alredlllambetraihlichaamlgnerte Ian-aw Corporation of America, Detroit.

sarpesatiaaornelawase am asrll it, me. Serial No. trans Thisinvention relatestopneumatictimingdevices, and particularly to a timing device operatedbytheairdeliveredtoanairoperated mechanism for accurately controlling the time oi its operation in some instances and to permit control by the operator for any desired duration.

'ihetimingdeviceissimilarincomh'uctionto that described and claimed in the copending application oi A. H. Haberstump, et al., Serial No.

137,486, tiled April 3, 1942, and lllllned to the assignee oi the present invention.

Air is metered to the interior of a movable element in the housing oi the device where pressure is built-up to advance the element after a predetermined time for closing the control valve. In the, device 0! the above-mentioned application a trigger is provided for opening the valve to permit .a complete cycle of operation or the timing device out of the control of the operator.

The present invention pertains to a new and novel control for the valve wherein the trig er maybemoved asmalldistancetopermitthe operation oi the mechanism under the control of the operator and to be moved a predetermined greater distance for operating the mechanism underthe time control cycle. This is accomplished bytheuseoiastemonthevalvehaving a collar engaged by a pawl on the trigger which controls the position oi the valve when only partially moved and which releases the collar on the valve stem when moved a predetermined distance to have the valve closed by the timing mechanism of the device. The pawl on the trigger may be manually moved out of engagement with the collar on the valve rod to permit the trigger to be swung about its pivot to p rmit the device to be attached to and removed from the mechanism.

Accordingly, the main obiects oi my invention are: to provide a valve and actuating trigger for a timing control device oi an air operated mechanism which may be actuated to operate the mechanism under complete control of the operator or which may be actuated to have the mechanism operated by the time cycle of the device; to provide a pawl on a trigger of a timing device which engages a collar on the stem oi a control valve for positively controlling the operation 0! the valve when moved a small amount and which releases the collar when moved a further amount to have the valve closed by the timing mechanism of the device; to provide a projection on A the pawl which engages and controls a valve timing device which permits the pawl to be manually released from the valve to permit the trigger to 13 Clalms. (Cl. 131-13.)

be moved away from operating position; to slot the trigger in a manner to have a portion 0! the web thereof engage the pawl to position the pawl relative to the collar of the .valve so as to disengage thereirom when the trigger is moved its full amount: and in general, to Provide an operating trigger for controlling the valve of a timing device which is simple in construction, positive in operation, and economical oi manuiacture.

Other objects and features of novelty of my invention will be either specifically pointed out or will become apparent when referring, for a better understanding of my invention, to the following description taken in conjunction with the accompanying drawing. wherein:

Figure 1 is a view, partly in section and partly in elevation, of a timing device for an air operated mechanism embodying features 01' my invention; 4

Fi 2 is a broken side viewoi the structure illustrated in Fig. 1, as viewed from line 2-4 thereof.

I have illustrated a handle 5 of an air operated device 6 which may be a riveting gun or the like, having on the end thereof an L-shaped conductor 1 on which a timing device I is secured. This portion of the device and mechanism has been more fully illustrated and described in the abovementioned copending application. The timing device 8 embodies a housing I having a chamber ii in which a flexible bellows I2 is disposed. The interior oi the bellows communicates with a passageway I3 which joins with a passageway it through a control valve II and a relief valve it.

An inlet eway I'I communicates with a chamber II which is connected by a passageway II with the passageway l4 and the conductor 1 by which fluid is introduced to the mechanism 6, as described more fully in the above-mentioned copending application. The present invention pertains to the improved control valve and trig er which will now be described in detail.

A valve seat II, of rubber or similar sealing material, is retained against a shoulder in the chamber II by the end oi the threaded plug 22 which retain the seat in position. A valve 23 engages the seat to prevent the passage or air from the intake passageway l'l beyond the seat.

The valve 13 is mounted on or forms a part of a stem '24, one end of which projects within the chamber II, the other end of which extends through the plug 22 and is provided on its outer end with spaced collars II and 2t. Flanged washers 21 and 28 seal both ends of the stem against leakage of air from the chamber II. The

plug 22 has a central recess 29 which communicates through ah annular orifice II with the passageway IS. The gasket 28 is disposed against the bottom wall oi the recess on which a spring 32 rests for retaining the valve in open position when the stem 24 is released by the actuating element.

An operatingtrigger 34 is mounted in a slot 35 in the housing on a pin 28 which extends through the walls thereof. A spring 31 is mounted on the pin and is employed for urging the trigger in a clockwise directiori. The trigger is a stamping of channel section, the flanges of which support a pin 38 on which a pawl "is mounted for pivotal movement. A spring 4| urges the pawl against a tongue 42 in the web of the trigger. The tongue 42 may be deflected out of the plane of the web of the trigger to position a slot 22, of the pawl relative to the collar 26.

The-slot engagement between the pawl and the collar 28 provides a positive control between the trigger and the valve when the trigger is initialiy moved to permit the operation of the mechanism 6 for any length of time under the control of the operator. when the trigger, however, is moved substantially its full amount coun-' terclockwise, as illustrated in dot and dash lines,

the lip 44 of the pawl rides over the collar 26 to free the collar from the pawl and transfer the control of the valve 22 to the timing device which will close the valve at the end of the time cycle.

The advantage of this optional control to the valve resides in the ability of the operator to continue the operation of the mechanism I for a period shorter or longer than the time cycle for which the device was set. If the device 6 is a riveting gun it may be advantageous to employ the timing cycle for swaging a number of like rivets. The riveting gun may be operated. at the will of the operator, by moving the trigger only a portion of the way to swage a rivet which is greater or lesser in diameter than the rivets of the series without changing the adjustment of the timing mechanism of the device.

I have illustrated a thumb screw 44 which pro- J'ects within the passageway I! on the outlet side of the device for cutting down the flow of fluid through the passageway to have the gun strike a lighter blow, which is desirable when rivets are swaged in soft aluminum sheets or like material. By so locating the control element 46 full pressure is applied to the timing device which will operate in a normal manner. It will be noted that the pawl 39 is provided with an end portion 41 which projects through an aperture in. the web of the trigger 84 in position to be manually moved inwardly to separate the pawl from the collar 26. This permits the trigger 34 to be rotated about the pin 36 in a clockwise direction to a position in which it will not interfere with the handle 5 when the device I! is being attached or removed therefrom.

The spring 31 provides sumcient tension to the trigger 34 to move the stem 24 outwardly against the strength of the spring 22 to thereby maintain the valve 22 in closed position whether or not air pressure is supplied to the chamber l8. This prevents the operation of. the device through a time cycle when the pressure is first introduced to the chamber It, as would occur if the valve were urged to open position by the tension of the spring 22.

In operation, when the trigger 34 is moved initially a portion of its degree of travel, the

valve 23 is unseated and manually retained inunseated position under the control of the operator until the operator releases the trigger and permits it to return to its initial position, that shown. Should the operator move the trigger to the position illustrated in dot and dash lines, the pawl 39 will force the stem to the left into .the chamber ll until the collar 25 engages the end of the plug 22. As this occurs the end 44 of the pawl moves out of engagement with the collar 28 and the control of the operation of the mechanism will be eifected by the timing device if the operator retains the trigger in its fully moved position. Pressure will be bled through thevalve l5v into the interior of the flexible beilows l2 where it will build up over a period of time until it becomes great enough to extend the bellows and engage and move the stem 24 to the left to move the valve 23 to closed position. After the valve 23 reaches closed position the drop of pressure in the passageway l4, the handle 5, and the mechanism 6 will permit the pressure within the bellows and passageway If to open'the relief valve l6 and the bellows will return to its original position.

operator has complete control over the operation of the device and "can operate the riveting gun or other mechanism for any length of time or through a predetermined time cycle, which cycle may be interrupted at any time by the operator.

I claim as my invention:

1. An air operated timing device having a control valve, timing mechanism for moving said valve to closed position at the end of a time cycle, a trigger for operating said valve to open position to provide a flow of fluid to operate said timing mechanism, means interconnecting the trigger and valve which when the trigger is moved to fully operated position releases the valve to permit it to operate at the end of the time cycle and which engages and closes the valve independent of the time mechanism when the trigger is moved from fully operated position to its initial position, and a spring for returning the trigger to its initial position which may occur to close the valve before the end of the time cycle.

2. In a timing device, a control valve, an operating trigger, variably movable between two extreme positions, a pawl interconnecting said trigger and valve for positively retaining said valve in open position when the trigger is moved a portion of its extent of travel between said two extreme positions, and a spring eifective to close said valve when said trigger is released after having first been moved less than a sufllcient portion of its extent of travel to disengage the pawl from the valve, said pawl moving out of engagement with said valve when the trigger is moved its full extent of travel in opposition to said spring,

3. A timing device including in combination, a housing, a control valve, amovable element in said housing for moving said valve to closed position, adjustable means for controlling the flow of air to said movable means for regulating the time required to produce its movement, a trigger, means on said trigger for positively engaging said valve for holding said valve in open or closed position to have the device function under the control of the operator, which means moves out of engagement with the valve when the trigger is moved a greater amount to permit the valve to beclosed by the movable element.

4. In an air operated timing device for a mechanism to be operated, a housing having a chamber, a movable element in said chamber, a. control valve mounted in position to be engaged by said movable element, a trigger, a. pawl on said trigger for opening said control valve, a spring on said trigger for urging said pawl to close said valve, said pawl moving out of contact with the control valve when the trigger is moved a predetermined iurther amount to have the valve thereafter closed by said movable element.

5. In an air operated timing device as part of an air actuated mechanism, a control valve, a trigger, a pawl on said trigger releasably connected to said control valve in such manner as to open and close said valve by the action of said trigger, and a time control mechanismfor moving said valve to closed position when the pawl is released from the valve.

6. In an air operated timing device as a part of an air actuated mechanism, a control valve, time control mechanism for moving said valve to closed position, a pivoted trigger, a pawl pivoted to said trigger and releasably connected to said valve in such manner as to open and close said valve by the action of said trigger, and means on said trigger for adjusting the position of said pawl for moving both the trigger and pawl away from valve operating position.

7. In an air operated timing device as a part of an air actuated mechanism, a control valve,

time control mechanism for moving said valve to closed position, a pivoted trigger, a pawl pivoted to said trigger and releasably connected to said valve in such manner as to open and close said valve by the action of said trigger, a spring for urging said valve to open position, and a spring urging said trigger to valve closed position having sufllcient strength to overcome the spring of said valve.

8. In a device having a valve provided with a flange, a trigger for operating said valve, a spring for biasing said trigger to urge said valve to closed position, and a pawl pivoted on said trigger having a slot in which said flange is releasably engaged, said pawl acting to open and close said valve and to disengage said valve from said trigger when said valve is fully open, all through the action of said trigger.

9. In a fluid actuated timing device for a mechanism to be operated, a housing having a chamber as well as an inlet port and an outlet port for the operating fluid, a movable member in said chamber responsive to pressure of fluid flowing from said inlet port, a control valve for said fluid mounted in position to be engaged by said movable member and moved to closed position upon movement of said member, a trigger operably mounted on said housing and having a return spring associated therewith for urging the trigger toward initial idle position, a pawl movably mounted on said trigger, a spring urging said pawl into effective position on the trigger for engaging a portion upon said valve to open the latter when said trigger is 'moved through only a part of its full range of movement so as to allow the operator to control the time of operation of said mechanism, said pawl being removed from efiective contact with said portion upon said valve when the trigger is moved through its full range of movement and causing the valve to open subject to closure by said movable member according to a predetermined time cycle but said pawl being adapted to re-engage said portion upon said valve if the trigger is released to allow the operator to interrupt the operation through said time cycle at will and to resume control of the time of operation of said mechanism by means of said trigger.

10. In an air operated timing device for a mechanism to be operated, a housing having a chamber, a movable element in said chamber for closing a Control valve after a predetermined time, a control valve mounted in position to be engaged by said movable element when said element is actuated by a fluid delivered through said valve after said valve is open, means for operating said valve, said means including a trigger and a pawl normally interconnecting said trigger and valve, said pawl being adapted to release said valve when the valve is moved to full open position, and a spring for urging said trigger to cause the pawl to re-engage and close said valve upon release of the trigger prior to the completion of the time cycle.

11. In an air operated timing device for a mechanism to be operated, a housing having a chamber, a movable element in said chamber actuated by said air, a control valve mounted in position to be engaged by said movable element, a trigger, a pawl on said trigger for moving said control valve for admitting air to said element and for disengaging said valve whenthe trigger is fully operated, said pawl positively retaining said valve in open position when moved by the operator a portion of its degree of travel, and a spring for moving said trigger for closing said valve when the trigger is released prior to the completion of the time cycle.

12. In an air operated timing device for a mechanism to be operated, a housing having a chamber, a movable element in said chamber, a control valve mounted in position to be engaged by said movable element, a trigger, a pawl interconnecting said trigger and valve for opening said control valve when the trigger is moved, a spring on said trigger for urging said pawl to close said valve, said pawl moving out of contact with the control valve when the trigger is moved a predetermined i'urther amount to have the valve thereafter closed by said movable element at the end of a predetermined time. said pawl trigger.

ALFRED H. HABERSTUMP.

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