US3078722A

US3078722A - Mercury actuated g-triggered time delay

Info

Publication number: US3078722A
Application number: US102076A
Authority: US
Inventors: Kongelbeck Sverre
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-04-10
Filing date: 1961-04-10
Publication date: 1963-02-26
Anticipated expiration: 1980-02-26

Description

Feb. 26, 1963 s. KONGELBECK 3,078,722

MERCURY ACTUATED G-TRIGGERED TIME DELAY ATTORNEYS 2 Sheets-Sheet 2 S. KONGELBECK MERCURY ACTUATED G-TRIGGERED TIME DELAY VIE Feb. 26, 1963 Filed April 1o, 1961 ATTORNEYS KONGELBECK United States Patent 3,078,722 MERCURY ACTUATED G-TRIGGERED TIME DELAY Sverre Kongelbeck, Silver Spring, Md., assigner to the United States of America as represented by the Secretary of the Navy Filed Apr. 10, 1961, Ser. No. 102,076 11 Claims. (Cl. 7353) This invention relates generally to a time delay mechanism; more particularly it relates to a mercury actuated acceleration responsive mechanism for use in actuating a desired element at a specified instant in time following the occurrence of an initial event.

lt is the object of the present invention to provide a time delay mechanism so constructed as to be operable in response to acceleration, whereby to actuate a desired element at a specified instant in time following the termination of said acceleration,

A further object of this invention is to provide a timing unit for a time delay mechanism, said unit being so constructed as to integrate the product of acceleration and time to determine at what point after the initiation or" said acceleration a specied vclocityis attained, and to subsequently measure the passage of a specified time interval.

Another object of the present invention is to provide k a timing unit for a time delay mechanism, said unit being so constructed as to permit a variety of periods of time delay.

lt is also an object of the present invention to provide a time delay mechanism having means to actuate a source of stored energy.

A still further object of this invention is to provide an acceleration responsive time delay mechanism having means to prevent accidental operation thereof.

Another object of this invention is to provide a time delay mechanism so constructed that its operation will be entirely independent of ambient air conditions.

Gther objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reetrence to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. l is a perspectiveview of the time delay mech anism of the invention;l

FiG. 2 is an enlarged longitudinal section of the mechanism, showing the construction thereof;

FIG. 3 is an axial section, on the line 3-3 of FIG. 2, the mechanism being shown in full lines at an intermediate position during the first, or acceleration integrating, half of the operating cycle, the initial position of the cam and link being indicated in broken lines;

FIG. 4 is a detail side elevation further showing the movement of elements of the mechanism during the operating cycle, the positions of the cam, the link and the plunger, after completion of the first, or acceleration integrating, half ot' the cycle being indicated in full lines, and the nal positions of said three elements after completion of the second, or time delay, half of the cycle, being shown in broken lines;

FlG. 5 is a detail sectional view showing the actuating unit portion of the mechanism after the plungers have been released from their cocked positions; and

FG. 6 is a detail section of a modified form of the cylindrical core of the mechanism.

The present invention relates to a mercury actuated acceleration responsive time delay mechanism. Time delay mechanisms are employed in applications where one element must be actuated at a predetermined instant in time following the occurrence of some initial event.

"ICC

For example,` they may be employed to actuate the ejection mechanism of an aerial missile nose cone at a predetermined instant in time following the termination of thrust generated by the missiles engine. The time delay mechanism which is the subject of the instant invention is operated by acceleration-created G-forces and is therefore capable of use in any application where accelerations of a sutlicient magnitude are present, such as in rocket propelled missiles. Moreover, since the time delay mechanism of the instant invention employs a self-contained actuating fluid it is completely independent of ambient air pressure.

Asis shown in FIGS. 2 and 3, the device consists of three principal components, a mercury actuated timing unit A, and actuating B, and a linkage system C operably connecting the timing unit A with the actuating unit B.

The mercury actuated timing unit A includes a cylindrical housing 2 having screw threads 4 and 6 on its inner surface at the upper and lower ends thereof, respectively. An integral, inwardly directed annular projection 8 is positioned centrally within said housing 2, the upper end face of said projection forming an abutment Wall 1t?. Disposed within the housing 2 is a core assembly 12.

The core assembly 12 includes a central core 14 having an integral annular flange 16 positioned medially thereof, said ange having upper 'and lower radial end faces i8 and 2t), each of which has an annular groove 22 and 24,' respectively, therein. The ilange 16 also has a plurality of circumferentially-spaced bores 26 therethrough, Said bores being positioned radially outwardly of the annular grooves 22 and 24.

Secured to they upper and lower end faces 18 and 20 of ange 16 by a pair of

retainer rings

28 and 30 and a plurality of screws 32 are an upper bellows 34 and a lower bellows 36, the bellows each being constructed of a flexible, resilient, chemically-inert material such as polyethelene. The bellows are closed at their outer ends and have radially-projecting rims at their inner ends, which rims are clamped to the end faces 18 and 2G of annular flange 16 by the

retainer rings

28 and 30, said retainer rings having rounded annular projections 3S and 4t), respectively, thereon which cooperate with annular grooves 22 and 24 to secure the bellows to the end faces 18 and 2t! in sealed relationship therewith. Each

retainer ring

28 and 30 has a plurality of circumferentially-spaced bores 42 and 44, respectively, therein, one such bore being in alignment with each of the bores 26. The bores 44 are threaded, and the screws 32 are passed through the

bores

42 and 26 and are threaded into the bores 44 to thereby secure the retainer rings and the bellows in position.

The core assembly 12 is disposed within housing 2 with the lower face of retainer ring 30 in engagement with abutment wall lll. A cylindrical cap Vmember 46 having threads on the external lower end vthereof is threaded into the upper end 4 of the housing 2, thelower end face i8 of ysaid cap member being brought into abutment'withy the upper face of retainer ring 2S whereby the assembly 12 is clamped in position between said lower end face 4S and wall 10. The upper end face of the cap 46 has an annular socket 5t) therewithin, there being a peripheral groove 52 in the axially-directed wall of said socket medially thereof. A cap plate 54 having a plurality of perforations 56 therein is disposed within the socket S0 and is secured in position by a snap ring 5S, which ring is received within the groove 52.

The core 14 has a passageway extending longitudinally therethrough, Asaid passageway being composed of an upper bore 60 of reduced diameter, a lower bore 62 of enlarged diameter, and a frustoconical seat portion 64 extending between said upper and lower bores 66 and 62, the upper end of the upper bore and the lower end of the lower bore having threads for securing therein a metering plug 66 and a retainer plate 68, respectively. The metering plug 66 has a bore 70 extending therethrough, and the retainer plate 68 has an orifice 72 disposed centrally thereof.

Disposed within the lower bore 62 is a piston 74 having a threaded bore 76 extending therethrough, the piston being substantially smaller in diameter than said bore 62. 'Ille external upper end portion of the piston is reduced in diameter, and has a peripheral groove 78 extending therearound for reception of an inturned radial flange portion 80 of a bushing 82. The bushing 82 is of a chemically inert resilient material such as Teon, and serves to insure that a sealed relationship exists between the upper end of the piston 74 and the frusto-conical seat 64 when the former is in contact with the latter. The bushing 82 has a central opening therein of a diameter substantially the same as that of bore 76, and an orifice screw 84 extends through said opening and is threaded into said bore '76, the oriiice screw having a central bore 86 extending therethrough. The upper end of the screw 84 is circumferentially enlarged, the enlarged portion serving to clamp the bushing in position. The bottom face of piston 74 and the top face of plate 68 have recesses 88 and 90 therein, respectively, and a coil spring 92 is positioned to extend between the bottom radial walls of said recesses, said spring 92 serving to urge the piston upwardly to cause the bushing-bearing upper end thereof to engage seat 64.

The core 14 has a pair of generally radially directed bores 94 and 96 therein, which bores place the bore 62 in communication with the space between lower bellows 36 and the exterior cylindrical surface of said core. The annular flange 16 has an elbow-shaped bore 98 therein, the radially-outward end of said bore being threaded for reception of a screw plug 100. The screw plug 100 carries an O-ring 102 thereon, which is received within an annular socket portion 104 of the bore 98 to thereby seal the plug relative to the annular ange. The axiallydirected portion of bore 98 confronts the space between the lower bellows 36 and the cylindrical exterior of the core 14.

Disposed within the housing 2 below the lower bellows 36 is a bearing plate 166 having a diameter smaller than the diameter of said housing. The top face of the bearing plate has a recess 168 therein of a size to easily receive the closed outer end of the lower bellows. An end closure plate 116 is screwed into the threaded lower end 6 of the housing 2, said plate having a deep recess 112 in the top face thereof and a large central opening 114. A coil spring 116 extends between the lower face of the bearing plate 106 and the bottom wall of the 4recess 112 in plate 1.10, said lower face and said bottom wall having therein

annular grooves

118 and 120, respectively, for receiving the opposite ends of the spring 116. The spring 116 functions to normally urge the bearing plate 106 upwardly, whereby to compress the lower bellows 36.

The initial position for the core assembly 12 is that shown in FIG. 2, with the lower bellows 36 being held in a compressed position by the coil spring 116. While the assembly is in said initial position the interior thereof is filled with mercury 122, the mercury occupying the volume defined by the expanded upper bellows, the compressed lower bellows, core 14, piston 74, retainer plate 68, spring 92, plug 66 and screw 84. The mercury is admitted to the interior of the assembly 12 through elbow-shaped bore 98, and thence ilows through bores 92, 94, 96, 70, and 86 and orilice 72 until the interior of said assembly is fully occupied thereby. Screw plug 160 is then inserted, thus sealing the mercury within the core assembly.

The timing unit A is constructed so as to function as an acceleration integrator during the first half of its operating cycle and as a timer during the last half of said cycle. With the mercury 122 contained within' the upper bellows the timing unit is accelerated in an upward direction. Such acceleration creates G-forces which cause the mercury -to depress bearing plate 186 against the force of spring 116, whereupon the mercury flows into the lower' bellows, the precise course followed thereby being more fully described hereinafter. The amount of mercury transferred from the upper bellows to the lower bellows is proportional to the degree of acceleration and the time over which it is exerted; hence the timing unit actually integrates the product of acceleration and time over the period during which acceleration is occurring. The spring 116 acts as a bias on the integrating action, since the force exerted thereby must first be overcome before the lower bellows can expand to permit commencement of the flow of mercury thereinto. Thus, if the bias is substantially greater than one G small accelera-tions exerted over short periods of time may not be sufficient to overcome the force of spring 116, and uo flow of mercury will occur.

When acceleration-created forces decline and the How of mercury into the lower bello-ws ceases the piston 74 is urged into contact with seat 64. r1`he second, or time delay, half of the timing devices operating cycle then commences. The spring 116 urges the lower bellows upward, -thus causing the mercury to liow through bores 86 and 70 back into the upper bellows at a rate determined primarily by the force exerted by said spring 116 and by the size of said bores. In the mechanism of the invention the expanding and collapsing movements of the lower bellows during the acceleration integrating and timing halves, respectively, of the timing devices operating cycle are utilized to operate a mechanical linkage system, which system in turn actuates a source of stored energy.

The actuating unit B includes an elongated, generally rectangular housing 124 having therein a centrally positioned bore 126 and firs-t and second

elongated chambers

128 and 130, the bore 126 and the

chambers

128 and 130 lying in a common plane and being parallel to one another and to the longitudinal axis of said housing. Four integral, spaced posts 132 of equal length extend upwardly from the housing 124 into abutment with closure plate 110, said posts each being connected -to said closure plate by a screw 134 which passes through said closure plate and into a threaded bore in the upper end face of the post.

An annular lip 136 is formed about the upper end of the bore 126, and the shank portion 138 of a plunger 140 extends through the opening defined by said lip and into the bore 126. The plunger 146 has an integral annular collar 142 positioned near the lower end thereof, and a spring 144 is disposed about the shank 138 and extends between the lip 136 and the upper face of said collar 142 for urging the plunger into the bore 126. The lower end of the plunger is enlarged to form a cylindrical head portion 146, there being a circumferential groove 148 defined between the head 146 and the collar 142, the lower side wall 150 of said groove being tapered.

Positioned within each of the

chambers

128 and 130 is an impact piston 152. Each of the pistons 152 includes an enlarged head portion 154 and a reduced in diameter shank portion 156, a radial shoulder 158 extending between the outer cylindrical surface of the head por tion and the shank. The lower ends of the head portions 154 are reduced in diameter to form rounded annular shoulders 166. A coil spring 162 is disposed about each shank 156 and extends between shoulder 158 and the bottom wall of the chamber within which the piston is disposed, said spring serving to urge the piston downwardly within said chamber.

Openings

164 and 166 are provided in the adjoining walls between central bore 126 and the rst and

second chambers

128 and 130, said openings being positioned to confront the shoulders 168 when the pistons 152 are in their cocked positions as shown in FlG. 2, the springs 162 being compressed and the upper end faces of the Shanks 156 being in engagement with the bottom walls of their respective chambers. Retaining balls 16d are disposed within the openings 16d and 166 and cooperate with the shoulders 1nd and the cylindrical outer surface of the head portion lilo of plunger ldd to maintain the pistons 152 in said cocked positions. Upon downward movement of the plunger 1d@ within its bore 126 the groove 148 will be brought into alignment with the balls 16S, said balls lthereupon being urged into said groove by the combined action of the springs 162 and rounded shoulder 169. When the balls have moved a sufficient distance into the groove ldd the impact pistons 152 are free to move. The impact pistons each strike one of a pair of firing pins 170, said firing pins in turn actuating the desired device. The time delay unit of the instant invention can be employed to actuate any of a number of desired devices. ln the embodiment shown in the drawings the tiring pins 17d are utilized to puncture bottles 172 containing a compressed gas.

Referring 4to FIG. 2, a manifold 174 is attached to housing 124 by screws 176, a gasket 17S of suitable material being interposed therebetween. The manifold has a pair of reduced diameter bores 120 positioned to confront the first and second chambers 12S and 13d in housing 121i, the firing pins 170 being slidably received within said bores. An O-ring 182 is positioned in an annular socket ld at the upper end of each bore 1S@ and serves to maintain the tiring pins in sealed relationship with the manifold. An enlarged bore 1&6 extends from each bore 18). and terminates in a flared outer end 138. A shoulder 19t! is formed where the bores 1S@ and 186 meet, against which shoulder a collar N2 on the firing pin 170 abuts to thereby prevent the pin from extending too far into its chamber 128 or 13d.

The bores 156 are placed in communication by a bore 194. Referring to FIG. 3, a transverse bore 1% intersects said bore 194 and contains an exhaust plug 198. T he plug 1% has a collar Zitti near one end thereof which cooperates with a nut 2il2 at its opposite end to secure the plug within said transverse bore 19d, G-ring seals 2%@ and 2%, positioned in annular recesses in the manifold 174i and the plug 19S, respectively, being utilized to maintain the plug in sealed relationship. An annular recess 2% is positioned midway of the plug 19S, and is in communication with bore 194. The plug contains an elbow-shaped outlet bore 210 which communicates with annular recess 2&8, bore 194, and the bores ld, whereby gas released from the bottles 172 may flow to the atmosphere.

The bottles 172 are each secured to confront one of the ared outer ends 138 by a

bolt

2,12, a plate 21d and a nut 216 (FlG. l), O-ring seals 21S being positioned in circumferential grooves in the bores 136 to place the outer ends of the bottles in sealed relationship with said bores.

T he linkage system C, which is best seen in FIGS. 2 and 3, is contained partly within housing 2 and partly within housing 124, and includes a cam 22d pivotally connected by a shaft 222 to a pair of opstanding integral projections 224 and 226 on the housing 12d. The projections 22d and 226 have aligned openings 228 and 23h, respectively, therein, within which are disposed suitable flanged bushings 232 and 23d. The shaft 222 passes through the

bushings

232 and 234, and is secured in position by a pair of snap rings 23d positioned in peripheral grooves near the opposite ends thereof.

The cam 220 has an inner 23S and an outer 2d@ cam track therein, said cam tracks being in the shape of an arc and being drawn on radii emanating from a common point positioned at the center of the shaft 222. The inner and outer cam tracks are of a width to easily receive a cross-pin 242 carried by the plunger Mtl, and are connected at one end by a slot 24d which lies along a radius emanating from the center of shaft 222. The end of the outer cam track 240 opposite the radial slot 244 is open, whereby to permit the cross-pin 242 to be inserted into said track. The upper end of the plunger 140 has a slot 246 therein, the cross-pin 242 being connected to the plunger near the upper end thereof and being adapted to extend across said slot.

The lower, forked end of a connecting link 248 is conn ected to a point 25d on the cam 220 by a pin 252,

suitable bushings

254 and 256 being disposed between the forked legs ofthe link and the opposite sides of the cam. rthe point 25h is positioned on a line which is substantially degrees removed from a line emanating from the shaft 222 and bisecting the cam tracks 238 and 240, said point 25d being spaced from the shaft 222 a substantial distance whereby to define a lever arm. The upper end of the link 24S is connected to a yoke 258 by a pin 26d, suitable bushings 262 and 264 being provided between the opposite sides of said link and the legs of said yoke. The yoke 253 has a shank 266 thereon which passes through the central bores of roller bearing units 268 and 27@ mounted in a hub portion 272 of bearing plate 106, a snap ring 274 disposed in a peripheral groove near the upper end of the shank 266 holding the same in position. The bearing units 268 and 270 are secured tov the plate MP6 by retainer plates 276 and 273 and screws 280 and 2&2, respectively. i

The operation of the mechanism is as follows. The device as shown in FIG. 2 is in an unarmed position, the mercury'l22 being contained within the upper bellows 34, the impact pistons 152 being secured in their cocked positions, and the cross-pin 242 being disposed in the inner cam track 238. (The initial, unarmed positions of the cam 220 and link '24S are indicated by phantom lines in FIG. 3.) Upon rapid acceleration of the device in an upward direction the acceleration integrating half of the operating cycle commences, and the following occurs. The acceleration, if great enough and if of a sucicnt duration, creates G-forces which act on the mercury 122, pressing it downwardly. This in turn depresses piston 7d, thus opening a passage therearound through which the mercury may llow at a rapid rate, such mercury passing through the opening 72 in the plate 68 and thence into the lower bellows 36, such flow, together with the G-forces, acting to force the bearing plate 1% downwardly. Bores 94 and 95 in the core and bore 86 in screw 84 faciiltate the ow of mercury into the lower bellows. Downward movement of the bearing plate, because of the design of the cam 226 and the link 248, will cause the cam to swing in a clock-wise direction, the amount of such swinging movement obviously being determined by the amount of mercury transferred into the lower bellows. FIG. 3 depicts the action of the device as G-forces are applied, the piston 74 being shown in its depressed, open position and the cam 22d being shown by solid lines in a partially shifted positionf If the acceleration created forces are great enough and are of sufficiently long duration swinging of cam 220 will continue until the cross-pin 242 reaches the end of the inner cam track 23S, this position corresponding to a minimum Velocity attained by the mechanism; At this point the spring 144 will cause the plunger 14)v with its attached cross-pin 242 to move downwardly a small amount whereby the cross-pin will enter the outer cam track 24d via radial slot 244, this position being shown by solid lines in FIG. 4, The device is then armed. lf acceleration forces are insuicient or are too short in duration (which is equivalent to saying that if a specified minimum velocity is not attained), the cross-pin 242l will remain in the inner track 238, the device will not become armed, and the mercury will be caused to flow back into the upper bellows by the action of spring 116. i

Once the device is armed, and as long as it is being accelerated at such a rate that the magnitude of the G-forces does not decrease, no further action will occur. As soon as the G-forces begin to drop in magnitude the second, or

acreage' time delay and firing half of the operating cycle commences.

Upon a sufficient lowering of G-forces the spring 92 will urge the piston 74 into sealing engagement with the conical seat 64, the upper and lower bellows now being in communication only through the bore 86 within the screw 84. The spring 116 now exerts a force on the lower bellows 36 though the bearing plate 106, such force urging the mercury to ow from the lower bellows through the opening 72 and bores 86, 60 and 70 back into the upper bellows, the rate of such iiow being regulated primarily by the size of the bore 86 within the screw 8d. As liow of the mercury progresses the bearing plate 106 is caused to move upwardly, such action, because of the design of the linkage system, causing swinging of the cam 220 in a counter-clockwise direction. When the cam has shifted to the point where the cross-pin 242 is freed from the outer cam track 24) (this position being indicated by phantom lines in FIG. 4) the plunger 140 is caused to move into the central bore 126, thus freeing the impact pistons 152 in the manner explained hereinabove. This position is shown in FIG. 5. The tiring cycle of the device is now complete.

As is evident from the above description, the length of the time delay from the beginning to the end of the firing half of the operating cycle is determined primarily by the rate of ow of mercury between the lower and upper bellows. Therefore, the length of the time delay may be preset to any one of an innumerable amount of periods by varying the size of the opening around the piston 74 when it is in its retracted position, the sizes of the bores 94 and 96, the size of the bore 86 inthe screw 34, the size of the opening 72 in the plate 68, the size of the opening 70 in the plug 66, the size of the bellows, the amount of mercury utilized, or any combination of the above stated variables.

The time delay mechanism of the invention is especially suitable for use in the rocket propelled aerial missiles where an element must be actuated at a specified time after the rocket engine ceases operation. In such an application the timing device first operates to integrate the product of acceleration and time during the period up to a specified minimum velocity. If the rocket engine should fail before this minimum velocity is attained the amount of mercury transferred to the lower bellows will be insufficient to cause the cross-pin 242 to enter the outer cam track 240, and hence the mechanism will not be armed and the firing half of the operating cycle will not commence. If the amount and duration of thrust is sufficient to arm the mechanism, the time delay and firing half of said operating cycle will begin at thrust termination, and after passage of the preset period of time delay the desired device will be actuated.

It should also be realized that the timing unit A can function as a velocity indicator, although such a use is not shown in the drawings. During the first half of its operating cycle the timing device integrates the product of acceleration and time, the resultant of which integration is in reality velocity. Thus, the amount of mercury moved into the lower bellows (and hence the degree of enlargement of said bellows and the amount of rotational shifting movement of cam 220) is directly proportional to the velocity of the mechanism. Therefore, by measuring the displacement of cam 220 velocity can easily be determined. 'Ihe maximum velocity than can be measured is of course determined primarily by the size of the bellows, the amount of mercury employed, and the rate of flow of the mercury between the bellows.

The cylindrical head 146 of the plunger 140 is provided with an opening 284, and the housing 124 is provided with a pair of opposed elongated slots 236, whereby Va suitable tool may be inserted into the opening 284 to retract the plunger in order to prepare the device for operation.

In order to prevent an undesirable buildup of air prest3 sure within the chambers 12S and 130 upon release of the pistons 152, vent openings 287 are provided' in the housing 124 near the lower end of each said chamber.

It has been found that a rapidly repeating, or vibrating,

' impact action of large magnitude may cause mercury to flow in small increments from the upper bellows into the lower bellows, thus operating the device in a ratchet-like manner. Since such a ratchet-ty e action could conceivabiy cause arming of the device before such is desired, an anti-ratchet modification of the device has been devised, such being shown in FIG. 6.

As shown in FIG. 6, a modified cylindrical core 288 is provided with a transverse bore 296 which is in communication with a longitudinal bore 292. The longitudinal bore 292 has therein a frusto-conical seat 294, a iirst portion 296, and a second, reduced portion 298. Disposed within the longitudinal bore 292 is a valve assembly comprising a spring 39), a ball 302 of a size to seat in sealed relationship on the conical seat 294, and an operating stem 364, the stem 394 having an enlarged portion 306 disposed within the first portion 296 of the longitudinal bore 292. The outer end of bore 290 is sealed by a plug 3%, and a screw plug 31@ is threaded into bore 292 to secure spring 300 in position. The remainder of the core 233 is identical in construction and operation to the core 14, and includes a central bore 6b', a piston 74', a spring 92', a retainer plate 68 and a metering screw 66.

In operation, the core 233 is mounted in the device of FIG. 2 in the same manner as core 14, with the lower end of stern 334 in contact with the end wall of lower bellows 36. The operating stem 394 is initially urged inwardly against the force of the spring 360 by the outer end of the lower bellows and the bearing plate 106, such action holding the ball 302 out of contact with the frustoconical seat 294. Thus, a passageway between the first and second bellows is established through bore 60', the transverse bore 290, and the first portion 296 and the second portion 298 of bore 202, said portions 296 and 29S being substantially larger in diameter than the portions of the operating stem 304 contained therein. Therefore, any incremental amount of mercury that is moved from the upper bellows to the lower bellows by ratchet action is free to flow back into the upper bellows not only through the regular flow path defined by the elements of the core, but also through the passageway of the anti-ratchet mechanism. If the passageway of the anti-ratchet mechanism is of suflicient size the ratchet effect of the device may be overcome, thus preventing accidental arming thereof.

When a large, sustained acceleration acts upon the device the mercury will iiow into the lower bellows in a rapid, continuous manner, thus enlarging said lower bellows at a rapid rate. As the lower bellows enlarges, the stem 304 is free to move and the spring 3th) urges the ball 302 into sealing engagement with the frusto-conical seat 29d, thus closing the passageway through the antiratchet mechanism. The timing device thereafter operates in the same manner as previously explained.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A time delay mechanism including a housing means, a G-force operated timing device mounted within said housing means, said device including a central core having passageway means extending therethrough, an upper bellows, a lower bellows, each of said bellows being closed at its outer end and being attached at its inner end to said core, the interiors of said upper and lower bellows being placed in communication by said passageway means, a uid within and substantially filling one of said bellows when it is in an expanded position, movable fiow restrictmg means within said passageway for allowing saidfluid to flow from one of said bellows to the other thereof more easily in one direction than in the other, and resilient means within said housing for urging said lower bellows toward a collapsed position, actuating apparatus also mounted within said housing means, and means within said housing means for operably connecting said timing unit with said actuating apparatus, said last-mentioned means being adapted to release said apparatus from a cocked posi-tion after passage of a predetermined period of time, as measured by the ow ot iiuid between the bellows within said timing device.

2. A time delay mechanism as recited in claim 1, wherein said actuating apparatus includes at least one piston, resilient means for bias.ng said piston toward a released position, and means for restraining said piston in a cocked position against the biasing force of said resilient means.

3. A time delay mechanism including a first housing, a G-force operated mercury controlled timing device mounted within said first housing, a second housing, said second housing being connectedr to said first housing and including a central bore at least one elongated chamber disposed parallel to said bore and a transverse opening extending between said central bore and said chamber, actuating apparatus contained within said second housing, said apparatus including a spring biased actuating piston disposed within said chamber, a spring biased plunged disposed within said central bore, a ball detent disposed within said opening and cooperable with portions of said plunger and said actuating p.ston to retain said actuating piston in a cocked position against the force of its biasing means, and connecting means disposed within said first and said second housings for operably connecting said timing device with said plunger, whereby said actuating piston will be released for movement after the passage of a predetermined period of time, as measured by said timing device.

4. A time delay mechanism including a first housing, a G-force operated timing device mounted within said first housing, said device including a central core having passageway means extending therethrough, an upper bellows, a lower bellows, each of said bellows being closed at its outer end and being attached in sealed relationship at its inner end to said core, the interiors of said upper and lower bellows being placed in communication by said passageway means, liquid mercury within and substantially filling one of said bellows when the bellows is in an expanded position, movable flow restricting means within said passageway for allowing said mercury to flow from one of said bellows to the other thereof more easily in one direction than in the other, and resilient means within said first housing for urging said lower bellows toward a collapsed position, a second housing, said second housing being connected to said first housing, actuating apparatus mounted within said second housing, said apparatus including at least one actuating piston, a resilient means for biasing said piston toward a released position, and means for restraining said actuating piston in a cocked position against the biasing force of said resilient means, and connecting means disposed within said first and second housings for operably connecting said timing unit with said restraining means, said connecting means being adapted to release said actuating piston from said cocked position after passage of a predetermined period of time', as measured by the iiow of mercury between the bellows within the timing device.

5. A time delay mechanism as recited in claim 4, wherein said passageway means includes an upper bore portion, a lower bore portion of greater diameter than said upper bore portion, and an intermediate bore portion extending between said upper and said lower bore portions, the wall defining said intermediate bore portion forming an abutment surface, and wherein said flow restraining means includes a hollow piston, said piston being disposed within and being substantially smaller in diameter than said lower bore portion, and resilient means for secutive enlargementand collapsing movements of said lower bellows will cause said cam element to pivot sufficiently to release said last-mentioned connecting means.

7. A time delay mechanism as recited in claim 4, wherein said core contains a second passageway means, said second passageway means placing the first-mentioned passageway means in communication with the lower bellows, and including means within said second passageway for closing the same when said lower bellows is in an enlarged condition.

8. A time delay mechanism including a first housing, a G-force operated timing device mounted within said first housing, said device including a central c-ore having passageway means extending therethrough, an upper bellows, a lower bellows, each of said bellows being closed at its outer end and being attached in sealed relationship at its inner end to said core, the interiors of said upper and lower bellows being placed in communication by said passageway means, liquid mercury within and substantially filling one of said bellows when it is in an expanded position, ow restricting means including a spring biased hollow piston disposed within said passageway for allowing said mercury to flow from the upper bellows to the lower bellows more easily than in the reverse direction, and resilient means within said first housing for urging said lower bellows toward a collapsed position, a second housing, said second housing being connected to said first housing and including a central bore, at least one elongated chamber and an opening extending between said central bore and said chamber, actuating apparatus contained within said second housing, said apparatus including an actuating piston disposed within said chamber, resilient means also disposed within said chamber for biasing said actuating piston toward a released position, a plunger disposed within said central bore, resilient means for urging said plunger into said central bore, a ball detent disposed within said opening and cooperable with portions of said plunger and said actuating piston to retain said actuating piston in position when it and said plunger are both restrained against the force of their respective resilient means, said plunger having a reduced diameter portion thereon into which said ball detent enters when said plunger is released and moves into said central bore, such movement of said ball detent releasing said actuating piston for movement, and connecting means disposed within said first and said second housings for operably connecting said timing unit with said plunger, said connecting means being adapted to restrain said plunger against the force of its associated resilient means and to release it for movement into said central bore after pasf sage of a predetermined period of time, as measured by the fiow of mercury between the bellows within the timing device. Y

9. A time delay mechanism as recited in claim 8 wherein said connecting means includes a cam element pivotally connected to said second housing, said element having an inner and an outer cam track in communication with each other, said outer cam track being open at one end, means extending between and cooperable with said cam element and said lower bellows for causing said cam element to pivot in response to enlarging and collapsing movements of said lower bellows, and pin means carried by said plunger and initially receivable within said inner cam track, whereby enlargement of said lower bellows resulting from the ow of mercury thereinto will cause said 11 cam element to pivot', causing said pin means to enter said outer cam track, and whereby subsequent collapsing movement of said lower bellows will cause said cam element to pivot in the opposite direction, thereby disen` gaging said pin means fromsaid outer cam track and releasing said plunger.

10. An acceleration responsive timing device, said device including a housing, a central core mounted within said housing and having passageway means extending therethrough, an upper bellows, a lower bellows, each of said bellows being closed at its outer end and being attached in sealed relationship at its inner end to said core, the interiors of said upper and lower bellows being placed in-communication by said passageway means, liquid mercury within and substantially iilling said upper bellows when that bellows is in an expanded position, means within said passageway for controlling the flow of said mercury from one bellows to the other, and resilient means within said housing for urging said lower bellows into a collapsed position, whereby when said device is accelerated in an upward direction mercury will be transferred from the upper bellows to the lower bellows, the amount transferred and the consequent expanding movement of the lower bellows being proportional to the product of acceleration and time integrated over at least a portion vof the time duration of the acceleration, and whereby after said acceleration ceases said resilient means will act to collapse the lower bellows and to thereby cause mercury contained therewithin to flow therefrom back into the upper bellows, the rate of such return ow being controlled by said ow controlling means in said passageway.

1l. An acceleration responsive timing device as recited in claim l0, wherein said passageway means includes an upper bore portion, a lower bore portion of greater diameter than said upper bore portion, and an intermediate bore portion extending between said upper and said lower bore portion, the wall delining said intermediate bore portion forming an abutment surface, and wherein said means for controlling flow includes a piston having a bore therethrough, said piston being disposed within and being substantially smaller in diameter than said lower bore portion, and resilient means for urging said piston into sealing contact with said abutment surface, said bore within said pist-on serving to meter the ow of mercury from -the lower bellows into the upper bellows.

References Cited in the file of this patent UNITED STATES PATENTS 2,698,657 Blomgren Jan. 4, 1955 2,872,538 McLean Feb. 3, 1959 2,926,609 Goey et al Mar. l, 196()

Claims

1. A TIME DELAY MECHANISM INCLUDING A HOUSING MEANS, A G-FORCE OPERATED TIMING DEVICE MOUNTED WITHIN SAID HOUSING MEANS, SAID DEVICE INCLUDING A CENTRAL CORE HAVING PASSAGEWAY MEANS EXTENDING THERETHROUGH, AN UPPER BELLOWS, A LOWER BELLOWS, EACH OF SAID BELLOWS BEING CLOSED AT ITS OUTER END AND BEING ATTACHED AT ITS INNER END TO SAID CORE, THE INTERIORS OF SAID UPPER AND LOWER BELLOWS BEING PLACED IN COMMUNICATION BY SAID PASSAGEWAY MEANS, A FLUID WITHIN AND SUBSTANTIALLY FILLING ONE OF SAID BELLOWS WHEN IT IS IN AN EXPANDED POSITION, MOVABLE FLOW RESTRICTING MEANS WITHIN SAID PASSAGEWAY FOR ALLOWING SAID FLUID TO FLOW FROM ONE OF SAID BELLOWS TO THE OTHER THEREOF MORE EASILY IN ONE DIRECTION THAN IN THE OTHER, AND RESILIENT MEANS WITHIN SAID HOUSING FOR URGING SAID LOWER BELLOWS TOWARD A COLLAPSED POSITION, ACTUATING APPARATUS ALSO MOUNTED WITHIN SAID HOUSING MEANS, AND MEANS WITHIN SAID HOUSING MEANS FOR OPERABLY CONNECTING SAID TIMING UNIT WITH SAID ACTUATING APPARATUS, SAID LAST-MENTIONED MEANS BEING ADAPTED TO RELEASE SAID APPARATUS FROM A COCKED POSITION AFTER PASSAGE OF A PREDETERMINED PERIOD OF TIME, AS MEASURED BY THE FLOW OF FLUID BETWEEN THE BELLOWS WITHIN SAID TIMING DEVICE.