US 3813066 A
A mechanism for releasing another device or activating the same including a pivoted sear arm holding a spring loaded plunger in cocked position until the sear arm releases the same. The sear arm cannot move until both a timing means and an altitude sensing means release the sear arm. The sear arm, sear surface and its pivot are arranged relative to the plunger so that a moment of force exists to assist in rotation of the sear upon release thereof.
Description (OCR text may contain errors)
Unite States Eaterst 1191 Raznov 1 1 May 28, 1974 1 1 TIME AND ALTITUDE SENSING RELEASE MECHANISM  Inventor: Jerry L. Raznov, Philadelphia, Pa.  Assignee: Ametek, Inc., New York, N.Y.
 Filed: Sept. 14, 1972 211 App]. No.: 289,109
 US. Cl 244/150, 74/2, 244/149  Int. Cl B64d 17/56, 364d 17/58  Field of Search 244/149, 150; 294/83 A,
 References Cited UNITED STATES PATENTS 2,584,164 2/1952 Stallan 244/150 3,690,605 9/1972 Jones 244/149 Primary Examiner-Trygve Blix Assistant Examiner-Randolph A. Reese Attorney, Agent, or Firm-Smythe & Moore  ABSTRACT A mechanism for releasing another device or activating the same including a pivoted sear arm holding a spring loaded plunger in cocked position until the sear arm releases the same. The scar arm cannot move until both a timing means and an altitude sensing means release the sear arm. The sear arm, sear surface and its pivot are arranged relative to the plunger so that a moment of force exists to assist in rotation of the sear upon release thereof.
5 Claims, 11 Drawing Figures PATENTEUMAYB m4 MEF10F3 PATENTEUW P W 333111066 TIME AND ALTITUDE SENSING RELEASE MECHANISM This invention relates to a mechanism for releasing or activating a device or devices, such as parachutes, after predetermined altitude and time conditions have been met. The invention herein described was made in the course of or under a contract or subcontract thereunder with the .Iohnsville Naval Air Development Center.
In the dropping of loads or in activation of parachutes in stages, a simple, economical time-delay and altitude responsive apparatus is needed. Examples of various types of time-delay or altitude responsive devices are seen in the U. S. Pat. Nos. to Badowski 2,365,445, Yost 2,924,408, Minicucci 3,013,834 and Kinney 3,468,502. All of these devices are complicated. complex in structure and are difficult to manufacture.
One of the objects of the invention is to provide a reliable, simple and economical to manufacture device for releasing or staging devices such as a plurality of parachutes.
Another of the objects of the invention is to provide a simple altitude and time responsive releasing apparatus or mechanism of small size.
Merely by way of example, the invention can be employed in conjunction with the staged release of para chutes to control the delivery 'of a device carried thereby into the sea or water.
In such an instance. a line or restraining means can be attached to the device being dropped so as to hold a deployed parachute in relation thereto and so as to keep a second packed parachute on the device. Upon release of the line by the release mechanism of the present invention, the deployed parachute is set free and the packed parachute. such as one of different size, is permitted to become activated and take over control of the descent of the device being dropped.
In one aspect. the release mechanism has a reciprocable plunger in a housing, the plunger being spring urged, when cocked, to a releasing condition but being prevented from such movement by a pivoted or equivalent sear arm means. The sear arm means is prevented from releasing the plunger means by a timing or timedelay means and an altitude sensing means, both of which must move to sear releasing condition before the sear arm can rotate to release the plunger. In one form, the plunger has a pin engageable by a sear surface in such a manner that there is a small moment of force exerted by the cocked plunger which assists in rotation of the sear upon release thereof by both the timing means and the altitude sensing means.
If the mechanism is below the preset altitude of the altitude sensing means, it will release after the predetermined time of the time-delay means.
Other objects. advantages and features of the present invention will become apparent from the accompanying description and drawings, which are merely exemplary.
In the drawings:
FIG. I is a top view of one form of the invention;
FIG. 2 is a side view partially in section of FIG. 1;
FIG. 3 shows the sear arm of FIGS. I and 2 in a cocked position. the view being taken from the top thereof;
FIG. 4 shows the sear arm of FIG. 3 in released position;
FIG. 5 is a top view of another form of the invention;
FIG. 6 is a side view of FIG. 5; FIG. 7 is a view taken along the line 77 of FIG. 6;
FIGS. 8 and 9 are similar to FIGS. 3 and 4 except that they show the sear arm of FIGS, 5, 6 and 7;
FIG. 10 is a fragmentary view of an adjustable altitude sensing means that can be used; and
FIG. 11 is an illustration of one manner in which the invention can be used.
Proceeding next to the drawings wherein like reference symbols indicate the same parts throughout the various views, a specific embodiment of the present invention will be described in detail.
Referring now to FIG. I, mechanism can have a housing 21 carrying a plunger 22 which is reciprocable therein and is guided in apertures 23 and 24 thereof. Slot 25 is provided so that the loop of a line or other device 73 (FIG. II) can be placed on plunger 22 and held thereby when the plunger is released to its retracted dotted line position 26 (FIG. 2). Spring 27 is located inside of plunger 22 and is fastened at one end 28 to pin 29, pin 29 extending upwardly to 29A. The other end of the spring is held by pin 30. Slots 31, 31 in plunger 22 permit reciprocation of the plunger relative to fixed pin 30. Pin is fixed in any suitable manner at 32 to the frame. A cover plate 33 is suitably mounted on housing 21 at 33"34. Subframe 33 may have a lower plate 35 spaced therefrom by posts 36, 36 to subframe plate 33".
Altitude sensing assembly 37 is mounted on plate 33" and comprises a suitable diaphragm 38 having a reciprocable pin 39 mounted thereon. Pin 39 is reciprocable in aperture 40 subframe plate 35 so that when the diaphragm 38 is expanded, the pin will project below the plate 35 for a purpose to be described hereafter.
Timing mechanism assembly 41, which can be of any suitable conventional type. has a plunger 42 which is reciprocably movable upwardly (FIG. 2) by the timedelay means 41, after the timer is activated by removal of an arming pin 43. Timing blocking pin 44 is urged upwardly by spring 45 so that as it is released by actuation of timer 4I, pin 44 will move upwardly (FIG. 2) relative to the lower face of plate 35.
Sear arm 46 is pivotally mounted by pivot means 47 to plate 35 and is held in an inactivated position by pins 39 and 44 before firing or the release operation of the mechanism. Sear surface 48 is in contact with the upper end 29A of pin 29 when the plunger is cocked, by virtue of spring 27 exerting a force against sear surface 48. The sear surface 48 is angularly displaced relative to pivot 47 so that there is a moment arm relative thereto applying a force to the sear arm tending to r0- tate it in a counterclockwise direction (FIG. 1) or to a releasing position. Slot 49 is located in the sear arm and receives therein rotation limiting bolt or pin 50.
Pins 39 and 44, in the form shown in FIGS. 1 and 2, are received in slots 51, 52 in the ends of the sear arm 46 (FIGS. 3, 4) and when so positioned therein retain the sear arm in its FIG. 3 position.
Upon arming of the release mechanism by removal of arming pin 43, pin 44 will be withdrawn after a predetermined time lapse, such as two seconds, and will be withdrawn from a blocking position relative to sear arm 46. If the altitude is such at this time that pin 39 also is withdrawn from slot 51, the sear arm will then rotate to the position shown in FIG. 4.
Another form of the invention is illustrated in FIG. 5 wherein two springs instead of one are used. In this form, housing 53 carries reciprocable plunger 54 having a pin 55 projecting therethrough. Springs 56, 57 (FIG. 7) are attached at their opposing ends to the projected ends of pin 55 and to frame 53.
The altitude sensing assembly 58 can comprise one or more diaphragms, two being shown in FIG. 6 The timer mechanism assembly 59 has an arming means 60 similar to the prior described arrangement.
Sear arm 61 is pivotally mounted to plate 62 (FIG. 6) at 63. Pin 64 is carried by plunger 54 and, in cocked position, is held by sear surface 65 of the sear arm 61. The center of the pivot pin 63 preferably is located slightly to one side of the axial center line 66 of the plunger. For example, it may be offset 0.015 inches to 0.020 inches relative to the center line, as best seen in (FIG. 5). Preferably, the sear surface 65 may have a portion 67 which is approximately 12 relative to a transverse axial line of the housing and a portion 68 which is about 18 relative to a transverse axial line of the sear arm. Pin 64 can be located approximately at the intersection of the center line and the aforesaid change in curvature. Thus, when the sear arm is released by both the altitude sensing pin and the timedelay means, the sear arm will be rapidly released because of the force exerted thereon by the cocked springs.
The sear arm, shown in FIGS. 5, 6 and 7 and as illustrated in FIGS..8 and 9, may be provided with steps 69 and 70 instead of slots as in the form shown in FIGS. 1 to 4, inclusive.
An alternate form of the altitude sensing means is shown in FIG. wherein the diaphragms 76 are held between plates 77, 78 having spring means 79 for retarding diaphragm motion. Sear arm blocking pin 80 functions in a manner similar to that described for the prior forms. The diaphragm assembly is adjustably carried by post 81 which is adjustably carried in the assembly and can be turned relative thereto, pointer 82 being provided to indicate the altitude of operation. Spring means 79 can be fastened to adjusting screws 83. Plate 77 may be threadedly mounted on post 81 and lower plate 78 is fastened to the lowermost diaphragm and is movable therewith.
Merely by way of example, FIG. 11 shows one manner of use in which a device 71 to be dropped has the release mechanism 72 of the invention attached thereto with a line 73 having a looped end thereof carried on the cocked plunger. Parachute 74 has a loop 75 at the lower end through which line 73 passes. Packed or inactivated parachute 75A is also held inactivated by line 73. Upon actuation of the release mechanism 72 to release line 73, when both altitude and time conditions have been met, the inactivated parachute 75A will be permitted to open and the activated parachute 74 will be freed from the device being dropped.
It should be apparent that various changes may be made in the present release device without departing from the scope and spirit of the appended claims.
What is claimed is:
1. In a parachute release mechanism for controlling the descent of a device to be dropped, including housing means attached by line means to said device, reciprocable plunger means mounted in said housing means, for restraining device means to be released, a pin projecting vertically from said plunger means, spring means associated with said plunger means and connected to said pin thereof for urging said plunger means to a device releasing position, subframe means in said housing, sear arm means mounted in said housing and pivoted to said subframe means, said sear arm means having sear surface means intermediate its ends and slots in the ends thereof, said plunger pin extending into and engaging said sear surface means and holding said plunger means when said plunger means is in a cocked position, said spring means causing a force to be exerted on said sear arm means, an altitude sensing means in said housing having a pin projecting there from and releasably engageable with one of said sear arm end slots, timer means in said housing and having a pin projecting therefrom and releasably engageable with the other of said sear arm end slots, said sear arm means being restrained from moving by one or both of the pins of said altitude sensing means and said timer means but being movable after both said sensing means and said timer means are released therefrom.
2. In a release apparatus as claimed in claim I wherein the sear means is a single element mounted in line with said plunger means.
3. In a release apparatus as claimed in claim 1 wherein the altitude sensing means is adjustable.
4. In a release apparatus as claimed in claim I wherein said altitude sensing means includes diaphragm means carrying the pin thereof, and wherein the pivot of the sear means is offset from said line so as to assist in reducing the load on said altitude sensing diaphragm means.
5. In a release mechanism, the combination including housing means, reciprocable plunger means carried on said housing means for restraining device means to be released, spring means connected to said plunger means for urging said plunger means to a device releasing condition, a single movable sear means having slots in the ends thereof and mounted on said housing means, said sear means engaging a pin on said plunger means and holding the plunger when the plunger means is in a cocked condition, said spring means causing a force to be exerted on said sear means tending to move it from a plunger holding position, an altitude sensing means releasably engageable with said sear means and having a sear restraining pin engageable with one of said sear means slots, timer means on said housing means and having a sear restraining pin also releasably engageable with the other of said sear meansslots, said sear means being restrained from moving by one or both of said altitude sensing means pin and said timer means pin but being movable after both said sensing means and said timer means pins are released there-