US2604353A - Bomb slip, towing gear, and analogous releasable attachments - Google Patents

Description

July 22, 1952 Filed July 30, 1947 R. K. PIERSON ET AL 2,604,353

BOMB SLIP, TOWING GEAR, AND ANALOGOUS RELEASABLE ATTACHMENTS July 22, 1952 R. K. Pu-:RsoN ETAL 2,604,353

BOMB SLIP, TOWING GEAR, AND ANALOGOUS RELEASABLE ATTCHMENTS Filed July 50, 1947 2 SHEETS--SHEET 2 .rma/en TOR Patented July 22, 1952 "Freni" it FF i-C BOMB SHPITWNG GEAR. ANDANAL GOU's RELEAsABLE ATTACHMENTS- Reginaldirshaw .Pierson land Reginald Arthur Firman,

"Weybdg'e, England, assignors to VickersLArmstrongs Limited, London, England VmmlieatmhjJuly 30, 1947,"Ser`ial No. `*764,798 In 'Great Britain December 22, 1941 `Section 1,- Public Law 696, August v8,1946 Patent expires December 22., 1961 A 1 Claim.

The invention has reference t releas'able attachments for usefin conjunction with objects such as bombs, `mail Abags, .supply containers or -li-ke articles to .be dropped ffrom aircraft, or for use in towing operations, and in other analogous circumstances, such attachments being of the type comprising apair of load-engagin'gpvoted jaws which are held engaged by the presence of a .movable stop between opposed bearing faces on cooperating .parts of saidjaws, 'and in whichth'e arrangement is suchthat the load vitself vreacts to impose forces tending todisengage Ythe jaws and to eject said stop, locking mechanism Aimposing a restraining force on said stopin a direction opposed to said ejective force, and't'rp- .mechanism for releasing the `stop to permit disengagement Aof therload. In some known forms of attach-ment for these purposes the mechanism Ihas vbeenarranged in such manner that .the force necessary to be applied to release the load, as when dropping va bomb or disengaging'a towed object -or craft, is a function of the load to be .released, this eiTect being attained by arranging -for the load to exert such a force upon thelook- .ing mechanism that the latteris either` heldin .a neutral position or `subjected. to a slight .restraining action, thus preventing the .inadvertent v.release ofthe loadfe. g. through vibration. Where toggle mechanismshave been employed to ,transinit the unlocking lforce they 'are usually .arranged to work over a dead centre .between .the locked and unlocked positions, -so that 4it -is .neces- -sary to apply lsuiiicient power to operate them lthrough the dead centre position to unlock the attachment. Theres-istance to the unlocking operation due y.to friction alone is very considerable 'land where it is necessary Vto raise or wind in the :load 'slightly to permit the attachment to be 'released the 'operation can only .be .performed Vxtl'ith-tfh-e assistance offa certain degree of power.

object 'of the present inventionis the provision Pof an improved -form of Yreleasable -atmehment of the said type for use in the circum- 'st'ances referred fto, wherein the power requisite 'to '.'Iretain thefattachment in-engaged condition and'to factuate the mechanism for releasing the attachment willbe substantially less than that required in known forms of attachment, and which will possess .certain additional advantages which are apparent from the following ldescription.

lfin a releasa'ble'attachment of this type accordance with the present invention, thefjaws -arezs'o narranged that the .forces due tothe load acting thereonare for the greater part .balanced '2 by opposed reactions in the vjaws through the stop, "but fthe bearing faces o'f the 'jaw-parts'between which the 'stop is held are inclined 'to each other at anang'l'e Suchjas will, in'norm'al working cmditions, Vir'np'osfea slight 4ejectve force ohsaid s op.

Thema-nner 'which the invention is carried `int'o effect is hereinafter described withreference to the accompanying-drawings, which illustrate by -wayofexamme 'e re1eassb1e attachment een-- "structed `in 'accorda-nce with the invention, and which is suitable for'fus with bombs and'ot'her :articles to 'be dropped 'frein 'aircraft `in night. In 'the drawings, Fig. 1 'is' a general elevation of the attachment, Figs. 2 'and `3 are longitudinal sec- 'tions thereof .showing the V'respecting positions of the component 'parts (a) lwhen supporting a leed and (b) when'the load has been dropped. Fig. 4 *"a fragmentary detail view in section, 'showing the manner in 'which the attachment is locked 'in A'the vload-supporti'ng position when it 'is re*- ei'red ite Vprevent the attachment 'from being "released, ahdFig. '5 Vi's an end view 'of the sepaiable portion of the attachment, showing the electrica conte-ets thereon. A

"Referring to Figs. 1 to 5, it will b'e seen that 'the device there iuustreted comprises a housing lwhich capable of being xed tothe aircraft and .a slip I 6"'whi'c'h 'is shaped so as to be received ilto a Cavity `5I in the hO'l'lSig `5 Whenhoisted into piace by means :e: 'e cable 'Il 'passing under .a Vpulley I8'. When 'the "slip reaches the position shown in Fig. '2, 't't'ing closely within the housing,it is conveniently engaged byspring-actuated .retaining .jaws of which one is indicated in Fig. 1.at I 9, in Ythe manner described in Briti'sh Patent il'aecifieationNo. 497,009.. AThe means by which the slip can `bereleas'ed vfrom 'thehou'sng vare pref.- erably similar to `those vdescribed 'in said British A'Specification No. 497,009, consisting of a sliding wedge20 capable ofbeing moved by 'operation'of a cable 2| between Athe jaws'lLso as to disengage them from the vjaw-receiving slo'ts '22 of the slip, against the v.pressureo'f a spring `2`3.

The attachment Vfor .the bomb or other load comprises .two pincerlikejaw members 24, 2*'5, pvoted upon .a common .axis 26 and cooperating whenapproached `together solas to Ybe capable of eng-agingabomb .shackle ortho like, .the loop 21 of such shackle 'being sustained upon the tips .of;the.fiaws24, 25, which lare so spaced Iapart as to set uncertain forces tending to -separate them `when funderload. v'Ihe jaws 24, 25fare respectively provided with'pinoerglike extensions .having .co-

operating .plane .bearingvvfaces 24|, 25| (Figs. 2

and 3) arranged so that the insertion of a stop of roller form between such faces retains the jaws 24, 25 in the closed position; said faces 24|, 25|

are inclined to each other and the angle included between them so adjusted in accordance with surfaces. advantage of the frictional forces set up- (a) It will be understood that by taking between the bomb shackle 21 and the surfaces of the tips of the jaws 24, 25,'andl (b) between the jaws 24, 25 and their pivot Pin 2B, the ultimate ejective force imposed upon the stop can be ref stricted to a degree such that only a comparatively light contrary force need be exerted to retain the stop in the locked position, and vthat such retaining force may be still further geared down by the use of simple lever linkages in the locking mechanism. y

In the arrangement which characteris'es the present invention, therefore, the majority o' the disengaging forces imposedby the load are balanced by opposed reactions in the jaws 24, 25 through the roller-like stop 30, and only a suicient component of such disengaging forces is utilised for the provision of the stopejective force as will overcome the friction between the stop and the jaw-faces. component Vis determined by the inclination of vthe jaw-faces'to each other. Y,

The locking mechanism conveniently comprises a primary toggle linkage 28, 290i which the end laterally about the pivot connecting it to the toggle members 29, 3 I, the roller 30 being capable of sliding sufficiently between the surfaces 24|,

, 25| of the jaws 24, 25." Thus, any tendencies of Vthe load to movein a plane at right angles to the axis of the pivot pin 26 of the jaws are not resisted by thek stop 30, and no force other than the light ejective force acting upon therstop itself is'imposed upon the locking mechanism.

The attachmentmay be released mechanically by the impingement of a spring-pressed member 40 against, the'nger-piece 31.v Said member 40 is attached to the wedge-slide 20 so thatra movement of this member to the left (as viewed in Figs. 2 and 3) under the pressure of the spring 23 against the abutment shoulder 4|. would actuate the finger-piece 31 and release the toggles. To permit this action the stop 42 against which the slide 20 ordinarily abuts is made retractable, a cable 43 attached to said stop being operable so that by retractingsaid stop'42 ther pressure of the spring 23 causes the slide 20 to move as afore- The magnitudevof this adjacent the jaw- members 24, 25 carries the aforesaid movable stop (which here consists ofa roller 30) engaged between the inclined faces 24|, 25| of the jaw- members 24, 25,V the otherend of thev primary toggle being anchored to a fixed pivot'. Linked to the central pivot of said primary toggle 28, 29 is one end of a secondary toggle 3|, 32 of which the other end isanchoredto a fixed pivot 33 whilst the link 3| is extended to form a catch 34 which is normally retained byV a trigger 35 the resistance of which to the movement of the catch 34 is suilicient to withstand the ejective force imposed upon the movable stop 30 acting through the said toggle linkages 28, 29 and 3|, 32. The said trigger may be released ,as desired by either mechanical or electro-magnetic means; appropriate forms of both mechanical and electro-magnetic release means are hereinafter described. Both toggles are arranged to work only on the runway side of their dead centres, so that when'the trigger 35 is released the linkages are already free toA move towards their collapsed positions illustrated by Fig. 3 un- Y der the ejective thrust imposedthrough the jaws 24, 25 upon the roller 3i); YA'suitable tension spring 3S may be connected with the catch 34V in such manner as to counteract Vits inertia and to assist in the actuation of the toggleswhen the trigger 35 is released.

A nger-piece 31 may be connected to the catch 34 for the purpose of re-cocking and releasing the toggle mechanism by hand.y If desired, theattachment may also include sel-cocki'ngmechanism arranged to come into operation automatically when the jaws are engaged with a load.

Fixed abutments 38, 39 are preferably provided in conjunction with the jaws 24, 25'for the purpose of absorbing Vfore-and-aft reactions imposed upon the attachment by possible swinging movements of the load. It' willV be Y'understood that the double-toggle mounting `ofthe movable stop 30 is such as to permit saidstop to move said, resulting in the shackle 21 of the bomb or :the like suspended from the jaws, 24, 25,'being released. j Y

'A suitable form of electro-magnetic' release mechanism for the attachment, shown in Figs. 2 and 3, comprises a housing v44 enclosing an electromagnet 45 capable of being energised as desiredjthrough a circuit which includes leads 46 'and `41 connected to two spring contacts (of which one is shown at 48) fixed contacts 49 on the end-face of the slip (Fig. 5) and connections from said contacts to the magnet terminals at 50. Associated with the magnet are two pivoted armatures 5|, 52 normally held in the open positionl by a common compression spring 53 which passes through the hollow centre ofthe magnet. The armature 5I has a lever SII which, when the magnet isnotfenergised serves as an abutment holding the armature 52 in theopen position. The armature 52 is operatively connected with, or formed integrally with the trigger 35, and it will be seen that to permit the release of the trigger 35 it is necessary when the magnet 45 is energised, for the armature 5| first to be attracted towards it; this step removes the lever 5|| from its position holding the armature 52 which thereupon itself moves to the closed position, as shown in Fig. 3.V Thus the trigger 35 is raised from-engagement'with the catch'34 and the tog- `gle mech-anism is operated to releaserthe jaws 2,4, 25. The double-check lever arrangement here described for controlling the magnet armatures 5 I, 52 effectively serves to prevent the inadvertent release oi the trigger 35 by the movement of said vto closev the armature 52 and thus release., the

trigger 35,'such movement of the armature 52-is prevented by the presence of the lever5H; a Vsimilar but oppositely directedV force which-might tendtoY close the armature'5l is preventedlby the pressure of the springj53` for whichthe armaturev ,Y V52 and'trigger 35 then serve asan abutment;

In case it is desired'for any? reason to prevent the inadvertent release of a load, the mechanism YcanV be locked'by `insertingra shapedstop 31| between the finger-piece 31 and a fixed part of the housing I6, as shown in Fig. 4; such stop-31| may veasily be withdrawn as soon asV it is required to release Athe load.

jBy reason of the arrangement whereby the reactive force exerted bythe load upon the attachment is utilised to release the jaws 24, 25 and also to operate the toggle mechanisms which lock said jaws in engagement, it will be seen that the forces tending to release the jaws increase in proportion to the load. It is also an important feature of our improved attachment that the frictional forces due to the load act to relieve the release mechanism and not in opposition thereto as in certain known forms of attachment; for this reason it is found unnecessary to pay serious attention to the reduction of such friction between the working parts of the attachment.

What we claim as our invention and desire to secure by Letters Patent is:

A releasable load-attaching device for aircraft and the like, comprising a pair of load-gripping jaws pivoted on a common axis, opposed surfaces on said jaws adapted to receive therebetween a sto-p member, a movable stop member adapted to be engaged between said surfaces, means for locking said stop member in engagement between said surfaces, said stop member being movable with said surfaces upon common movement of said jaws about said axis, and means for releasing said locking means, the angle between said surfaces when the jaws are in load-engaging relation being such as to impose a slight ejective force REGINALD KIRSHAW PIERSON. REGINALD ARTHUR FIRMAN.

REFERENCES CITED The following references are oi record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,346,022 Hassel July 6, 1920 1,481,259 Harrison Jan. 22, 1924 2,061,083 Niemi Nov. 17. 1936 2,064,547 Laermann Dec. 15, 1936 2,416,028 Sloan Feb. 18, 1947

Images