US3638767A

US3638767A - Mechanical delay device

Info

Publication number: US3638767A
Application number: US11936A
Authority: US
Inventors: Fritz Elsner; Franz Becker; Heinreich Kolf
Original assignee: Dynamit Nobel AG
Current assignee: Dynamit Nobel AG
Priority date: 1970-02-19
Filing date: 1970-02-19
Publication date: 1972-02-01
Anticipated expiration: 1989-02-01

Abstract

A mechanical delay device provided with a throttle passage between two sealed chambers, with a piston in one chamber to displace a plastically deformable flowable mass from the one chamber to the second chamber. A pin extends through the second chamber to adjust the throttle passage and to surround it with a reset piston movable in the second annular chamber by relative rotation of two housing parts to move the flowable mass back into the first chamber.

Description

finite totes tnt Eisner et a1. Feb. 1, 1972 1541 MECHANECAL DELAY DEVHCE 15 1 References Cit d [72] Inventors: Fritz Eisner, Sieglar; Franz er, Bonn; UNITED STATES PATENTS Gama 1,379,086 5/1921 Davis et al. 185/37 [73] Assignee: Dynamit Nobel Ak I. .1; Min, 1,692,227 1 H1928 Segeler "1267/64 Troisdorf, Germany 2,460,l l6 H1949 Bazley .....267/137 2,991,992 7/1961 E1sner.... 1188/98 X [22} 1970 2,997,325 8/1961 Peterson .293/1 [21] Appl. No.: 11,936 3,254,741 6/1966 Greene, Jr. ..188/100 F X Related Application Dam Primary ExaminerGeorge E. A. Halvosa [63] Continuation of Ser. No. 744,095, July 11, 1968, Att0rneyCraig, Antonelli and Hill abandoned.

- {57] ABSTRACT [30] Foreign Application Priority Data A mechanical delay device provided with a throttle passage Aug. 2, 1967 Germany ..D53739 b t two l d hamber with a piston in one chamber to displace a plastically deformable flowable mass from the one ijfikgl "188/268, l88/297i1 iggl9igg chamber to the Second Chamber A pin extends through the n Field of Search lllllllllllll "188/268, 100 second chamber to ad ust the throttle passage and to surround it with a reset piston movable in the second annular chamber by relative rotation of two housing parts to move the flowable mass back into the first chamber 8 Claims, 1 Drawing Figure PATENTEU FEB 1m 3,838,767

INVENTORS FRITZ ELSNER FRANZ BECKER BY HEINRICH KOLF ATTORNEYS MECHANICAL DELAY DEVICE This application is a continuation of application Ser. No. 744,095, filed July 11, 1968, now abandoned.

BACKGROUND OF THE INVENTION There are many instances where it is desirable to provide a delay in a particular process, for example to automatically release a lock for an explosive initiating device after a predetermined period of time, but not to trigger the device prior to the instant of release. Likewise, it is often desirable or necessary to trigger a process automatically after an adjusta ble preset period of time.

For the above purposes, it is known to provide different devices, which may be mechanical, chemical, etc., that are dependent upon a great number of functions or influences. For example, it is known to provide a clock-type triggering device that will provide a switching or other procedure after a predetermined set period of time has passed. Also, a device is known wherein a lead lamina or platelet that is set on edge is gradually severed by a cylinder or a chisellike element under a biasing force so that the desired time length or the desired delay is accomplished thereby.

The known devices are disadvantageous in that their construction is relatively complicated and therefore very expensive. Also, many of these devices have the further disadvantage that they can be used only once, that is that they are destroyed with usage.

Some of the known devices that produce a time lag or delay are deficient in that they are temperature sensitive and/or that they do not have any provision for setting or altering the duration of the time delay, whereby their usefulness is substantially restricted.

SUMMARY OF THE INVENTION It is an object of the present invention to avoid the abovementioned disadvantages and provide a time delay device provided with a housing, a piston arranged in a bore of the housing and axially displacable therein to displace a plastically flowable, kneadable, puttylike mass, preferably of a silicone rubber base, into an auxiliary chamber.

Preferably, the auxiliary chamber is formed by conically flaring the housing away from the bore, which is of the same diameter as the piston, into an annular chamber; the flaring being an appropriate throttle point to set or change the duration of the time delay. With a fixed throttle cross section, the duration of the delay may be set or changed by varying the force acting upon the piston. Variation of the throttle may be in the alternative or in addition to varying the force on the piston, and is preferably accomplished by a movable member, preferably a pin forming the inside wall of the annular chamber, that moves toward and away from the housing flaring to vary the effective through flow cross section of the throttle passage formed therebetween. Preferably, the pin is axially displaceable by means of a threaded connection at the end of the housing facing away from the piston.

In order to provide for reuse of the device, the present invention provides for variation of the volume of the auxiliary chamber. According to the present invention, the volume is changed by means of an adjusting ring piston disposed between the pin and the adjacent housing wall forming the annular chamber, which ring piston is axially displaceable and forms one end of the annular chamber. Preferably, the ting piston is adjustably mounted in the wall of the housing by means of a threaded flange connection.

The adjustment of the ring piston may be accomplished in a particularly effective and simple manner by transversely dividing the housing into two sections. in the zone facing away from the main piston, which sections are rotatably mounted with respect to each other and axially fixed. One of the sections receives therein the main piston and the other section receives the adjusting pin, with the annular piston being threadably received in the one section and mounted for rotation with and axially displaceable with respect to the other section. With such a construction, the mere relative rotation of the two housing sections will move the annular piston in the annular chamber to reset the time delay device.

Advantageously, a pring is disposed between a housing cover and a flange formed on the main piston biasing the piston toward the flowable mass; with the force of this spring, the piston will be axially shifted and simultaneously displace the flowable mass into the annular chamber; the time period for this displacement is determined by the predetermined setting of the throttle passage, and the device to be ultimately actuated is operatively connected with the piston for actuation thereby after the displacement.

Also, a lock may be provided to secure the main piston in a predetermined position, particularly with the spring tensioned, so that the time delay device may be stored for a relatively long period of time in the ready to use condition, that is with the spring tensioned.

All of the components of the delay device of the present invention may be manufactured of metallic and/or nonmetallic materials. It is particularly desirable to employ only synthetic materials so that the delay device may not be detected by magnetic means, which is particularly advantageous with respect to mines.

BRIEF DESCRIPTION OF THE DRAWING Further objects, features and advantages of the present invention will become more clear from the following detailed description of the drawing, wherein the single FIGURE is an axial cross-sectional view of a preferred embodiment of the time delay device according to the present invention.

DETAILED DESCRIPTION OF THE DRAWING As shown in the FIGURE, the housing is divided into two sections 1 and 2, which are connected with each other for relative rotation and are axially nondisplaceable with respect to each other. This connection is accomplished by means of the pins 6 threaded into the tubular extension 3 of the housing section 2 to engage into an annular groove 5 of the tubular extension 4 of the housing section 1. The housing section B is provided with a central bore 7 receiving therein the axially displaceable main or actuator piston 8, which has its actuator member 9 extending outwardly from the housing. The piston 8 is provided with an annular flange 10 that cooperates with the housing cover 11 to receive therebetween the coil spring 12 that biases the piston 8 downwardly, as seen in the drawing.

An adjusting pin 14 is threadedly received within a corresponding threaded bore of the housing section 2 for axial adjustment. The top or forward end of the pin 14 cooperates with the flaring housing portion 15 to constitute a throttle passage 16. The adjusting pin 14 and the housing section 1 form an annular chamber 17 therebetween. An adjusting ring piston 18 telescopically engages the pin 14 and the housing section 1 to be axially displaceable for adjusting the volume of the annular chamber 17 by means of a threaded connection between the ring piston collar flange 19 and a suitably threaded portion of the housing section 1. The housing section 2 and the ring piston 18 are drivingly connected with each other for rotation and freely connected with each other for relative axial displacement by means of axially extending coupling pins 23 circumferentially spaced with respect to each other and received in corresponding axial bores in the ring piston 18 and the housing section 2.

A displacement puttylike or plastically deformable readily flowable mass 20 is provided in the bore 7 between the piston 8 and the throttle passage 16 to extend to the annular chamber 17. The piston rod or extension 9 is provided with two axially spaced annular grooves 21, which cooperate with a pawl or the like 22 that is suitably mounted on the cover 11 to engage in a respective one of the grooves 21 and prevent axial movement of the rod 9, particularly under the influence of the coil spring 12.

As soon as the blockage of the piston 8 is released, that is when the pawl 22 is retracted from the respective groove 21, the piston 8 will be axially displaced in the direction of the puttylike displacement mass 20. Blocking of the rod 9 and piston 8 may be accomplished by other types of devices than the pawl 22, and the displacement of the lock may be accomplished either manually or by means of nonillustrated automatic means. With axial displacement of the piston 8 under the influence of the spring 12, the displacement mass will be moved through the throttle passage 16 into the annular chamber 17 over a period of time determined by the setting of the effective through flow cross section area of the throttle passage 16 and/or the force of the spring 12. A control element or the like connected with the rod end 9 of the piston 8, which element is not shown and pertains to an apparatus likewise not shown, can effect the desired switching or triggering process. Suitably, actuation of the control element may be accomplished only after the piston 8 has moved a predetermined distance, corresponding to a predetermined or desired period of time, with the piston in a predetermined position, preferably its terminal position. For example, when the piston has moved the desired distance under the influence of the spring 12 toward the adjusting pin 14, the upper or outer one of the two grooves 21 will assume a position immediately adjacent to the pawl 22, which pawl 22 will engage in the adjacent groove 21, for example under the influence of a spring (not shown), to block further movement of the piston in its terminal position. In this connection, the triggering or switching process could be effected in a simple manner by means of the resulting movement of the pawl 22 into the on termost one of the grooves 21.

in order to reset the time delay device into its initial operative position, the housing section 2 is twisted or rotated with respect to the housing section 1, with the piston 8 being released by retraction of the pawl 22, until the ring piston 18 moves into the annular chamber 17 under the influence of the threaded connection at the flange 19 to press the previously displaced mass 20 out of the annular chamber 17, through the throttle passage 16 and back into the illustrated position within the bore 7. The piston 8 would be simultaneously displaced against the correspondingly increasing tension of the spring 12 by the resetting displacement of the mass 20 until the piston reaches its illustrated position wherein it is again locked or blocked by means of the spring urged pawl 22 automatically engaging into the innermost one of the grooves 21.

The time delay period, that is the time within which the mass 20 is displaced, or the velocity of the piston movement, may be varied by correspondingly varying the cross section of the throttle passage 16 by means of axially shifting the adjusting pin 14 by rotating it with respect to its threadingly engaged housing section 2, as may be seen from the drawing. In the alternative or in addition, the period of mass displacement or the piston speed may be varied by rotating the cover 11 to screw it into or out of the housing section 1, with which it has a threaded connection; thus, the precompression of the spring 12 is adjusted thereby.

it is particularly desirable to limit the adhesion of the puttylike silicone rubber mass 20 with the parts it contacts, so that it will flow through the throttle passage as satisfactorily as possible. This advantage is obtained according to the present invention by constructing the components that contact the mass 20 of a material that is particularly repellent with respect to the mass, that is a nonstick material, particularly a fluorinated polymer such as Hostaflon (polytrifluorochloroethylene) or Teflon. The materials for the remaining components are preferably synthetic so that they may be constructed by means of injection molding. The helical spring may be constructed of a glass-fiber-reinforced polycarbonate or polyester resin. lf there are no requirements with respect to constructing the delay device so that it may not be detected by magnetic means, conventional metallic materials may be employed for all of the components or some of the components.

While a preferred embodiment of the present invention has been specifically illustrated, and described along with variations, further modifications, embodiments and variations are contemplated within the spirit and scope of the present invention.

We claim:

1. A delay device with a predetermined time delay, comprising a housing having a bore therein at one end; a piston axially mounted in said bore, said piston being biased for axial displacement from an initial position to a terminal position, the time for said displacement determining the time delay of said device; means operatively associated with said piston for forming an enclosed expansible chamber having a throttle passage portion adjacent to said bore and an annular chamber portion within said housing; a plastically deformable puttylike mass located within the bore and partially within the expansible chamber to form a free space within said expansible chamber whereby biasing of said piston from the initial position to the terminal position effects displacement of said mass through said throttle passage and into said free space; a displaceable annular piston within said annular chamber; and rotatable means at the other end of said housing operatively associated with said annular piston for effecting displacement of said annular piston from an initial position against said mass whereby said mass is forced back through said throttle passage and the biased piston is returned to its initial position, said free space again being formed when the annular piston is withdrawn to its initial position.

2. The device of claim 1 wherein said piston is provided with an actuator member and means normally locking said actuator member against said biasing movement.

3. A delay device with an adjustable time delay, comprising a housing having a bore therein, a displaceable actuator piston mounted in said bore for movement from an initial position to a terminal position, the time for displacement of said piston determining the time delay of said device; means operatively associated with the actuator piston for forming an expansible chamber having a throttle passage portion adjacent to said bore and an annular chamber portion within said housing, said annular chamber having a larger outer diameter than the diameter of said bore; a plastically deformable puttylike mass within said bore and partially within said expansible chamber to form a free space therein; means biasing said actuator piston toward said throttle passage whereby said mass is displaced through said throttle passage and into said free space upon actuation of said piston; an annular piston axially displaceable within said annular chamber to occupy seiectively the annular chamber and to force the deformable mass through said throttle passage into the bore against the bias of said actuator piston, said annular piston having a flange threadably engaging said housing; and means for adjusting the effective through flow cross-sectional area of said throttle passage, said adjusting means including a pin forming the inside wall of said annular chamber, said pin being adjustably threaded for axial movement within said housing in opposition to said actuator piston.

4. The device of claim 3 wherein said deformable mass includes silicone rubber.

5. The device of claim 3 including means for axially locking said actuator piston.

6. The device of claim 3 wherein said housing is provided with at least two separate sections rotatably mounted with respect to each other; one of said sections threadingly receiving said annular pistonand the other of said sections receiving said pin; said other housing section and said ring piston being rotationally drivingly connected with each other and mounted for relative axial movement with respect to each other.

7. The device of claim 6 including a cover member at the outside end of said bore and a spring mounted between said cover member and said actuator piston.

8. The device of claim '7 including means for axially locking said actuator piston.

Claims

3. A delay device with an adjustable time delay, comprising a housing having a bore therein, a displaceable actuator piston mounted in said bore for movement from an initial position to a terminal position, the time for displacement of said piston determining the time delay of said device; means operatively associated with the actuator piston for forming an expansible chamber having a throttle passage portion adjacent to said bore and an annular chamber portion within said housing, said annular chamber having a larger outer diameter than the diameter of said bore; a plastically deformable puttylike mass within said bore and partially within said expansible chamber to form a free space therein; means biasing said actuator piston toward said throttle passage whereby said mass is displaced through said throttle passage and into said free space upon actuaTion of said piston; an annular piston axially displaceable within said annular chamber to occupy selectively the annular chamber and to force the deformable mass through said throttle passage into the bore against the bias of said actuator piston, said annular piston having a flange threadably engaging said housing; and means for adjusting the effective through flow cross-sectional area of said throttle passage, said adjusting means including a pin forming the inside wall of said annular chamber, said pin being adjustably threaded for axial movement within said housing in opposition to said actuator piston.

4. The device of claim 3 wherein said deformable mass includes silicone rubber.

6. The device of claim 3 wherein said housing is provided with at least two separate sections rotatably mounted with respect to each other; one of said sections threadingly receiving said annular piston and the other of said sections receiving said pin; said other housing section and said ring piston being rotationally drivingly connected with each other and mounted for relative axial movement with respect to each other.

8. The device of claim 7 including means for axially locking said actuator piston.