US2159920A

US2159920A - Timing mechanism

Info

Publication number: US2159920A
Application number: US111749A
Authority: US
Inventors: Foster E Weld
Original assignee: Gamewell Corp
Current assignee: Gamewell Corp
Priority date: 1936-11-19
Filing date: 1936-11-19
Publication date: 1939-05-23
Anticipated expiration: 1956-05-23

Description

May 23,1939. l RE. wELD 2,159,920

TIMING MECHANISM Filed Nov. 19, 1936 Patented May 23, 1939 UNITED STATES TIMING MECHANISM Foster E. Weld, Newton, Mass., assignor to The Gamewell Company, Newton Upper Falls, Mass., ar corporation of Massachusetts Application November 19, 1936, Serial No. 111,749

The present invention relates to timing mechanisms and more particularly to apparatus of the general type disclosed in the patent to Smith No. 1,538,010 dated May 19, 1925. The apparatus therein described is a device for timing the operation of a valve and is especially useful as whistle-blowing device for re alarm systems.

The object of the present invention is to improve the apparatus described in the Smith patent with .a particular view towards simplifying the construction, insuring. greater reliability and providing for greater precision and flexibility of `the timing control. To this end the invention comprises the apparatus hereinafter described and particularly defined in the claims.

In the accompanying drawing, illustrating what is now considered the preferred form of the invention, Fig. 1 is a side elevation of the valve; Fig. 2 is a section on line 2-2 of Fig. 1; Fig. 3 is a horizontal sectional view on an enlarged scale; Fig. 4 is a sectional elevation; Fig. 5 is a detail sectional view as seen from the opposite direction of Fig. 4 and showing certain of the parts in operating position; and Fig. 6 is a detail to be referred to.

The illustrated embodiment of the invention comprises a Whistle valve having a main Casing 6 with an inlet chamber 8 connected to a source of pressure such as compressed air, and an outlet chamber Il! adapted to be connected to a whis- Betvveen the chambers 8 and I0 the casing is formed with an `internal web I2 serving as a valve seat for thenormally closed main valve I4. The main valve i4 is formed on the end of a sleeve I6 which is adapted to slide in the casing and which is connected at its outer end With a piston I8 in a cylinder 26. The cylinder 26 is closed by a plug 22. The arrangement is such that upon the application of pressure to the rear, that is, the right hand side of the piston I6 as viewed in Figs. 3 and 4, the main valve I4 is opened to connect the source of pressure with the Whistle. small exhaust port 24 at the rear of the piston so that atmospheric pressure is normally maintained thereon and is also provided with small vents 26 in front of the pistonto prevent building up of pressure against movement thereof. The main valve is normally maintained closed,

not only by the air pressure on its face, but also` by a compression spring 28 which bears between the valve and a collar or bushing 30.

The operation of the main valve I4 is controlled by an intermediate valve which comprises a member Y32 having a cone-shaped surface normally The cylinder 26 is provided with a' seated in the opening at the center of the main valve. The valve member 32 is provided with a stem 34 received Within the sleeve I6 and of somewhat smaller diameter to aiord a passage for compressed air to the rear of the piston I8. Near the left-hand end, as viewed in Figs. 3 and 4, the stem is provided with an enlarged portion 36 to engage the Walls of the sleeve and serve as a guide for the intermediate valve. The portion 36 is provided with flattened surfaces to aiord passages for the air when the valve 32 is open. The stem 34 extends outwardly through an opening 3l in the closure plug 22 and near its end it has a portion 38 of reduced diameter. It Will be seen in Figs. 3 and 4 that the space around the relieved portion 38 of the stem normally communicates with the atmosphere. Upon a movement of the intermediate valve 32 to the left, as shown in Fig. 6, the outer end ofthe opening 3l is closed by the end of the stem 34 and the relieved portion of the stem then communicates at its inner end with the interior of the cylinder 26.

To effect an opening movement of the intermediate valve 32 the valve is provided with another stem 46 extending to the left and carrying at its outer end a piston 42. The piston 42 slides in a cylinder 44 Which is formed in a casting 46 bolted to the main casing 6. The movement of the valve is limited by the collar 30 which acts as a stop to be engaged by the valve member 32. The collar is held against a suitably formed face of the casting 46. The casing 6 and the casting 46 are sealed by a lead'gasket 48.

The cylinder 44 is normally supplied with the same pressure as the inlet chamber 8 by a port 56 which, as shown in Fig. 3 extends from the chamber 8 through the casing 6, the gasket 48 and the casting 46. The port 56 communicates with a port 52 and a port 54 which lead into the chamber 44 in back of the piston 42. The port 52 is in such position as to be covered by the piston 42 when the latter is moved` to the left. The port 54 is adjustable by means of a needle valve 56 threaded into the casting and adapted to be maintained in adjusted position by a suitable check nut. The port 52 is permanently closed by a taper plug 58. The chamber 44 communicates with a clean out passage 60 which is closed by a plug 62.

The parts as thus far described are maintained in the normal or inactive `positions as shown in Figs. 3 and 4 by virtue of the air pressure in back of the piston 42 Which maintains the intermediate valve 32 closed on its seat and thereby prevents passage of compressed air into the cylinder 28 at the rear of the main valve control piston i8. To operate the main valve, it is necessary rst to move the intermediate valve 32 to the left and this is accomplished by relieving the pressure in back of the piston 42.

The means for relieving the pressure in the rear of the piston l2 comprises a pilot valve in the form of a poppet yalve 68 which is normally seated at the end of a passage 66 leading into the rear of the chamber ll. The poppet valve has a stem 68 on which is mounted a piston or sleeve valve i8, the front porton of which is received in a chamber 'H of slightly larger diameter than the chamber 66. The rear portion of the valve is of enlarged diameter, as shown at l2, to slide in a cylinder l. An exhaust port 'i6 leads from both the front of the cylinder 'M and the chamber li; the port is always in communication with the cylinder l, but during certain phasesof the operation of the apparatus its connection with the chamber 'li is cutoff by the front end of the sleeve valve lil. A small ventI 78A connects the rear of cylinder '8 to atmosphere. Y

Itwillbe understood that the term front, as applied to any elementrherein, means that portion thereof which is nearest to the inlet and outlet chambers of the main casing 6, and that the term rear `means that portion farther removed; thus, the front end of the cylinder 'Mais the right end as viewed in Figs. 3 and 4.

AThe valve stem 68 is provided with a shoulder 80in back` of the poppet valve head 645i. This shoulder is adapted-to be engaged by the sleeve valve I0-to hold the poppet Valve open when the sleevevalve is in its forward position.

The cylinder 'lli is closed at the rear by arplug or cap S32-Which is bolted to the casting 46. A plunger 83 engaging the end of the Valve stem 68 protrudes through the plug 82.

The poppet valve 68 -is adapted to be opened by pressure applied to the protruding-end of the plungerY 83. This is preferably accomplished-by means similar to that fully described in the Smith patent above referred to, comprising an oscillating hammer 88 operated by toggle members 86 and .88, the latterof which is controlled by the armature 98 lof an electromagnet. This entire assembly is enclosed in a casing 82attached to the casting 46. When the armr86 is released the hammer llis rotated counter-clockwise to engage the end of the stem 68 and open the poppet valve 64.- 'I'he lever 88 is thereafter returned to its original position by a resetting or restoring rod 94 Vattached to a piston S6 which slides in a cylinder 98. formed in the casting 46. The cylinder is adapted to be connected under certain conditions to the air pressure supply, as Will be hereinafter described. The piston 96 is maintained in its normal position as shown in Fig. Llby a spring H00.

The sleeve. Vvalve 18 andthe restoring piston 96.are. operated from the compressed air supply when the intermediate valve 32 is opened. This is. accomplished by a port |82 which is formed in the closure plug 22 .and which communicates with the opening 3l vin the plug. The port E82 connects with a port E04 formed in the main casing 6 and the latter communicates in turn with a port V"36in the casting 86, leading into the sleeve valve cylinder l@ in the rear of the enlarged.portion..2 of the .sleevevalve- Normally the .ports 182,: |88. and A166 .are inactive to transmit.. .pressure to .therear of the va1ve.12, first Vclosed tube mounted on the casting 46.

because the intermediate valve 32 is closed, and second because the valve stem 3ft closes the inner end of the opening in the closure plug 22. Upon opening of the intermediate valve 32, however, the pressure is communicated from the chamber 8 to the rear of the sleeve valve 12.

A port |88 leads from the sleeve Valve cylinder M into` a port H0 which communicates with the restoring piston cylinder 9S. This communication is established through a suitable opening in the gasket d8. The port 488 communicates With either the front or rear of the cylinder 14, depending on the position of the sleeve valve member l2. When the Valve is in its normal or rear position as shown in Figs. 3 and 4, the port I88'connectswith the front of the cylinder and communication with the atmosphere is therefore established through the exhaust port i6. When the Valve is in its front position, as shown in Fig. 5, the port 108 communicates With the rear ofcylinder T8.

The .apparatus is provided with a timing chamber lf2-which, as shown in Fig. 2, comprises a A port l l8- leads fromthe poppet valve chamber 66 to the timing. chamberV I l2 The operation of the Valve is described as follows: Normally the parts are as shown in Figs. 3 and 4, the sleeve `valve 'i8 being in its rearward or left-hand position, and the intermediate valve 324 being maintained closed by the application of fullpressure in the cylinder Alli at the rear of the piston 82. When the operating lever 88 is releasedthe hammer 88 strikes the plunger 83 and opens the pilot valve 64. A relief'passage for the cylinderllll is thus establishedthrough the chamber 66 and the port 76. The pressure on the back of the piston l2 being relieved, the supply pressure on Ythe front of the rpiston moves the entire intermediate valve assembly tothe left untilthe valve member fengages the collar 38, the intermediate valve. is opened yand pressure is communicated to the rear of the main valve piston I8. The main .valve is vthen opened to blow the Whistle.

Thev length of time the main valve remains open is vdetermined by the time necessary for the restoration of balanced pressure on the intermediate valve piston 42. Thistiming action is effected in the followingV manner: When the intermediate valve opens, its stem 34 assumes the position of Fig. 6 to close the outer end of opening 31 in the closure plug and to permit communicationV between the cylinder 26 and the opening 31. Thus pressure is applied through the ports H32, |68 and ito the cylinder 74 in back of the enlarged portion `'l2 of the -sleeve Valve l0. The sleeyevalve moves forwardly, so that it enters the chamber 'll as shown in Fig. 5, thereby closing off communication of that chamber with the exhaust port 76.' The engagement of the end of Vthesleeve valvewith the shoulder 80 holds the poppet Valve open. Compressed air flows through the ports. 58 and 54 into the cylinder M and thence throughthe chamber 66 and the port H4 into the timing Ychamber l l2. The port 52 is now covered by the piston 82, and the rate of flow is therefore. governed by the adjustment of the needlevvalve 56.` Ultimately, after Va time determined by the rate of `flow andalsofby the size of theV timing chamber,.the pressure in the cylinder 44 rises to substantially the. same value as `that in the inletchamber Biand the piston '42 is moved forwardly to close the :intermediate valve. The diiferentialpressure .necessary for closing the intermediate valve arises from the fact that full supply pressure is now applied to the whole rear surface of the piston 42, but to less than the whole front surface thereof, atmospheric pressure only being applied to the outer end of the stem 34. After closure of the intermediate valve in this manner, the supply pressure is cut off from the cylinder 20, which then exhausts through the vent 24, permitting the main valve to close. It will be understood that the vent 24 is only large enough to insure proper venting after the pressure is cut off through closure of the intermediate valve, and does not prevent the building up of pressure in the cylinder 2|) during the time in which the main valve is to be held open. A feature of importance is the auxiliary port 52 which is uncovered by the piston 42 during the final portion of the movement of the intermediate and main valves, thus providing a rapid pressure equalization which reduces the tendency of the valves to chatter.

Concurrently with the building up of pressure in the timing chamber, as above described, pressure is also applied to the resetting cylinder Q8. This follows the forward movement of the sleeve valve, the port |08 being then in communication with the cylinder 14 in back of the portion '|2 of the valve. Since the cylinder in back of the valve is under pressure from the port l 06, this pressure is communicated through the ports |66 and llt, to act on the resetting piston 96. The arm 83 is thus returned to its original position to be latched by the armature.

When the intermediate valve and the main valve close, the stem 34 is returned toits original position-as shown in Figs. 3 and 4. The pressure is then cut off from the opening 3l of the closure plug 22, and the opening communicates with the atmosphere. The sleeve valve cylinder 'lll then exhausts through ports lil, |613 and |02, as well as the vent 18. The relief of pressure from the back of the valve causes the valve to be moved rearwardly under the influence of the pressure in the timing chamber, and the poppet valve which is no longer held open by the shoulder 3!! is closed by the pressure in cylinder 44. The vent 'i8 permits a quick return of the sleeve valve, but as explained in conjunction with the vent 24, it is sufficiently small so that the pressure can be properly maintained in the cylinder 14 when necessary. At the end of the rearward movement of the sleeve valve, the port |08 opens into the cylinder 14 in front of the valve portion l2. The restoring cylinder 98 and also the timing chamber H2 then exhaust to atmosphere through the cylinder 14 and the exhaust port l5, All of the parts are then resto-red to the normal positions of Figs. 3 and 4.

The duration of the blast may be varied either by changing the timing chamber to one of different size or by adjusting the needle valve 55. The needle valve adjustment alone affords a suitable range for most purposes. For example, in re alarm systems the blast is usually of a duration of one-half to one and one-half seconds. With a timing chamber of suitable size this range may be readily accommodated-by adjustment of the needle valve only. If a signal blast of longer duration is desired a timing chamber of larger volume may be substituted. Y

The whistle may be operated under manual control by means of a handle H6 pivoted on a bracket I8 which is mounted on the closure plug 22, The handle is provided with a foot |20 which is adapted to strike the end of the intermediate valve stem 34. Upon depressing the handle the intermediate valve opens, followed by opening of the main valve in the manner above described. 'Ihe timing control operates in a manner similar to that described for the automatic operation, except that the poppet valve is opened by the action of the sliding valve lll and therefore the cylinder 44 is not relieved to atmosphere. The cylinderl is, however, pla-ced in communication with the timing chamber as before, and a timing cycle is established in accordance with the time necessary to building up the pressure in the timing chamber, but this pressure is thereafter ineffective to permit restoration of the intermediate valve until the handle is released. Thus the whistle may be operated manually for a blast of any length. y

It will be seen that the mechanism in its general form and in the results attained is similar to that described in the Smith patent above referred to. There are, however, a number of important differences. In the rst place, the sleeve valve 'lil of the present invention is operated in both directions by air pressure as distinguished from the mechanical movement of the corresponding part of the Smith device in one direction. This makes for a simpler construction and more positive operation. Furthermore, the restoringA piston 96 and the timing chamber H2 are connected at the proper times with the supply pressure as distinguished from the Smith construction in which both of these parts are supplied by leakage around the piston of the intermediate valve. These improvements permit greater precision of timing and less elfe-ct from the presence of moisture, frost or oil in the space between the intermediate valve piston and its cylinder. Furthermore, any leaks around the restoring piston 96 do not affect the timing and accordingly more clearance between the piston 96 and its cylinder may be provided to avoid trouble from sticking.

Although the apparatus has been described as used for blo-wing a whistle of predetermined length of blast, the invention may be equally well applied to a time-controlled valve for any purpose. In other respects also the invention is not to be considered as limited to the particular embodiment shown and described, but may be modied within the scope of the appended claims.

The invention having been thus described, what is claimed is:

1. A timing device comprising an inlet chamber, a piston, a cylinder in which the piston reciprocates, means for normally maintaining substantially balanced pressure on the piston, means for initially establishing a'relief passage from the cylinder at one side of the piston, a second piston operable by pressure from said chamber for thereafter closing the relief passage, means for restoring the balanced pressure on the piston at a governable rate, said restoring means including a timing chamber in communication with the cylinder, and means operated by restoration of balanced pressure on the piston for cutting off pressure from said second piston to thereby cut off communication between the cylinder and timing chamber.

2. A timing device comprising a. casing having an inlet chamber, a cylinder, a piston in the cylinder having a face acted upon by the pressure in the inlet chamber, the casing having a port Vleading to the cylinder at the opposite face of the piston, initiating means for establishing a relief passage from the cylinder, means for thereafter closing the relief passage, means for restoring pressure in the cylinder through the port at a governed rate, a pressure actuated resetting device for the initiating means, and means forming a passage separate from said port for applying pressure to the resetting device.

3. A timing device comprising a casing having an inlet chamber, a cylinder, a piston in the cylinder having a face acted upon by the pressure in the inlet chamber, the casing having a port leading to the cylinder at the opposite face of the piston, initiating means for establishing a relief passage from the cylinder, means for thereafter closing the relief passage, means for restoring pressure in the cylinder through the port at a governed rate, a resetting piston for the initiating means, and a passage separate from said port for establishing communication between the inlet chamber and the resetting piston.

4. A timing device comprising a casing having an inlet chamber, a cylinder, a normally balanced valve operating piston, initiating means to establish a relief passage from one side of the valve operating piston, a resetting piston for the initiating means, the casing having a port between the inlet chamber and said one side of the valve operating piston and a port to establish communication between the inlet chamber and the resetting piston, means for closing said relief passage, and means for establishing pressure on the resetting piston through said second-named port.

5. A timing device comprising a casing having an inlet chamber, a normally balanced valve operating piston, means for initially establishing a passage for relief of pressure on one side ol' the piston, a sliding valve for controlling the relief passage, and means operated by movement of the piston to control communication between the inlet chamber and the sliding valve.

6. A timing device comprising a casing having an inlet chamber, a normally balanced valve operating piston, means for initially establishing a passage for relief of pressure on one side of the piston, a sliding valve for controlling the relief passage, and means operated by movement of the piston for applying pressure from the inlet chamber to the sliding valve to close the relief passage.

7. A timing device comprising a casing having an inlet chamber, a normally balanced valve operating piston, means for initially establishing a passage for relief ofY pressure on one side of the piston, a sliding valve for controlling the relief passage, means operated by the piston for controlling the application of pressure to the sliding valve whereby the relief passage is closed by the sliding valve after initial' movement of the piston, and means for restoring pressure on the piston at a governable rate.

8`. A timing device comprising a casing having an inlet chamber, a normally balanced Valve operating piston, means for initially establishing a passage forrelief of pressure on one side of the piston, a sliding valve for controlling the relief passage, means operated by the piston for controlling the application of pressure to the` sliding valve whereby the relief passage is closed by the sliding valve after initial movement of the piston, and a timing chamber to govern the time of restoration of pressure on the piston.

9. A timing device comprising an inlet chamber, a normally balanced piston, means for initially establishing a relief passage on one side of the piston, a timing chamber, a pressure operated sliding valve to control the relief passage,

and means operated by the piston for controlling th-e application of pressure from the inlet chamber on the sliding valve.

l0. A timing device comprising an inlet chamber, a normally k balanced piston, means Afor initially establishing a relief passage on one side of the piston, a timing chamber, a pressure operated sliding valve to control the relief passage, means forming a passage leading fromthe inlet chamber to the sliding valve, and a valve operated by the piston and controlling said passage. 11. A timingdevice comprising an inlet chamber, a normally balanced piston, a valve at one side of the piston to beinitially opened to establish a relie'.F passage, a sliding member to control the relief passage, means forming a passage connecting the inlet chamber with the sliding member, a valve operated by the piston to control said passage, and means for reestablishing pressure on the piston at a governable rate.

l2. A timing device comprising an inlet chamber, a normallybalanced piston, a poppet Valve to establish a relief passage from one side of the piston, a sliding valve to control the relief passage and having means to hold the poppet Valve open, means forming a passage to apply pressure to the sliding valve from the inlet chamber, a valve operated by the piston to control said passage, and means for re-establishing pressure on the piston at a' governable rate.

13. A timing device comprising an inlet chamber, a normally balanced piston, a puppet valve to establish a relief passage from. one side of the piston, a sliding valve to control the relief passage and having means to hold the poppet Valve open, means forming a passage to apply pressure to the sliding valve from the inlet chamber, a valve operated by the piston to control' said passage, means forming a pressure restoring passage for the piston, and a timing chamber communieating with the pressure restoring passage.

14. A timing device comprising an inlet chamber, a normally balanced piston, means for initially establishing a relief passage at one side of the piston to unbalance the piston, means for restoring balanced pressure on the piston including a sliding valve, means forming a passage from the inlet chamber to the' sliding valve, and valve means connected to' the piston normally ,closing the passage rand arranged to open' the passage when the piston is unbalanced.

15. A timing device comprising an inlet chamber, a normally balanced piston, means for initially establishing a relief passage at one side of the piston to unbalance the piston, means for restoring balanced pressure on the piston including a sliding valve, means forming a passage from the inlet chamber to the sliding valve, and Valve means connected to the piston normally closing the passage and arranged to open the passage I when the piston is unbalanced, saidvalve means being arrangedto relieve the passage to atmosphere upon re-establishment of balanced pressure on the piston. 16. A timing device comprising an inlet chamber, a normally balanced piston, means for vviriitially establishing a relief passage at one side of the piston to unbalance the piston, means for. restoring balanced pressure on the piston including a sliding valve, means forminga passage from the inlet chamber to the sliding valve, and a stem on therpiston normally closing said passage and having a portion of reduced Ydiameter to permit communication of tliepassagewith the inlet chamber upon imbalance of the pistornthe reduced portion normally communicating with the atmosphere to relieve the pressure on the sliding valve when balanced pressure is rer-established on the piston.

17. Valve mechanism comprising an inlet chamber, a main valve, a sleeve on which the main valve is mounted, an intermediate valve normally closing the sleeve, a main valve operating piston on the sleeve, a cylinder in which said piston reciprocates, a closure for the cylinder, a normally balanced piston for the intermediate Valve, a stem connecting the normally balanced piston with the intermediate valve and extending through the sleeve and closure, the stem having a portion of reduced diameter normally communicating with the atmosphere but adapted to communicate Withrthe cylinder when the intermediate valve is opened, and timing means controlled by the operation of said stem.

V18. Valve mechanism comprising an inlet chamber, a main valve, a sleeve on which the main valve is mounted, an intermediate valve normally closing the sleeve, a main valve operating piston on the sleeve, a cylinder in which said piston reciprocates, a closure for the cylinder, a

normally balanced piston for the intermediate valve, a stem connecting the normally balanced piston with the intermediate valve and extending through the sleeve and closure, the stem having a portion of reduced diameter normally communicating with the atmosphere but adapted to communicate with the cylinder When the intermediate valveis opened, and timing means controlled by the operation of said stem, the timing means including a valve member to control the establishment of pressure on the intermediate valve piston and a passage leading from the closure to said valve member.

FOSTER E. WELD.