US2494498A - Safety device - Google Patents

Description

2 Sheets-Sheet l ENTOR Jan. 10, 1950 1 WILLIAMS ETAL SAFETY DEVICE Filed July 30, 1945 Jan. 10, 1950 L. WILLIAMS ET AL SAFETY DEVICE 2 Sheets-Sheet 2 Filed July 50, 1945 THF/l Patented Jan. 10, 1950 UNI TED f vICE 2.494.438 "SAFETY DEVICE Lmvrenmeg` Williams fand Edward J. VVusler, Daye- .-ton,hio, assignorsztp .('icmn'alMotorsCorpora.,4 tion, Detroit,Mich-., a. corporationeofrDelaware.

Applicationzlyf, 1945; SerialiNog 6075720 4:01am. (CLM-55) 'Ihiszinyentionxrelatesito ing machine;v

It is among thenobjects ofthe present invention to provide la. processing machinewifth'asaety an improved processdevice "which prevents .Y .certainportions4 thereof.;

:supported by -a powerfdevice:idurlngs'operation of the machine, .from droppingvdu'eto grav-ity. when said power device is renderedV ineffective vWhile thema-chine is notaitilized.

Further objects-and advantages offfthe present a invention will be apparent vfromthe following-de- `fscription, reference 'fbeing hadto-fthe accompanying dra-Wings .Whereina preferred embodimentfof the present .invention is @clearly Vshown;A

The .Inacliinal asi shown .in the present ydraw;-l

ings comprises a frame having-a vcanrier --slidabli7 .attached theret'saidcarrier supporting z.tlfxe 'processing tool and itsoperator. .A prime mover,-.in the form ofan electric incitarn is ycarried by `-the frame and; drivesa -cam.-,. .A lil-uid powenactuated .revolution of the cam out ofits frestpositiomthe:

carrier will be moved bythe cam in `one direction against the counteractingforce of the fluid power actuated .dev-ice and during-another'portion .sa-id carrier .iwi-ll` be moved in ..the-opposite direction by the'fluid power actuated-device.' -un- 1 der. the con-trol of the cam. f rvIll'xe.safetydevice, which prevents the :carrier-y irom lfaillingdue:to gravity and particularly When-the uid poweractuated device .is deenergized,A provided by a block or .lug onthe cam, which is vinthe path `of r.

movement of the carrier cam `follower. when .the cam :is .in .its-restpostion and which is-moved .out vof this path uponfrotationof k'the cam.

In the drawings:

Fig. V1 showstheprocessingmachine in side :i

elevation.

Fig. .2 is a lplan view ci the machine. Fig. 3 is a. fragmentary sectionalfvie'wpartly in; section, showing certain" ofthe operating de# "tails' of "the" machine: t

Fig. 4 is a detail View of thelcontrolrswitchfac' tuator. l

Fig. I5 is al diagrammaticview'showingfthe'contour ofthe working surfaces'of 'thezcami Referring to the drawings thea-machine sis;

shownl comprising :a iframe .2 f+ :having t vertical slide-ways or gibs 2| to which the carrier..2z-fis .su-dany; attached.- .rrmsfcamersghasf @Hangul ar platform.' '.2 upon .which thezrzel'ectric .motorini-:isa

bythe: motor 241; 4drivesav shaft which in iturn operates'the processing. tool, a drill or the like, not shown in-fthe:drawings:A When a cutter, broach orzaiiyrtype Vof :reciprocating .tool is'tobe yused :withth-e machine, then the motor 2d lis, eliminated andsanyrsuitable.toolholderf is attached to the platform 23.

Carrier 22 has an opening 26a in which a block Z55-maybe secured :in `vertically adjustable Aposintionsmntthe .carrierfby .thepnch'plate 271.v An

abutment .28 is. provided :on :block A2li, said .v abutment `vl.lying fsubstantiallyssin thezplanezof the gibs `or:slide-Way 2l l A- camffollower stud i29 is .journailed.intbearings;provided in block 25 one .end

noia -the'cam'follower extending. from :said block.

Whenfthe" block-261is .in lits normal rest position and.likewisexthemarrier 22.,y Afor one is secured to themtherxfso thatnboth move together, said block engages the one. endl vofna .rod 3l, slidably sup- ;fportediinthe .frame 20, the 4other end of ksaid ,rod

engaging .a resilient bumperyelernent 32 .supported inwthesrecess of the. housing.A

.Aqprimefmover or. electric motor t is carried .by v.fra-Ine Mean-dnas a :shaft 4 l extending into a A:compartment .formed by two 'reinforcing Walls 42 andy I3-inthe trarne. This shaft .has a Worm ,pin-

ion 4t2-securedu thereto :which .meshes with and drives the worm whee145. A shaft 4@ journalled .inbearingslf and 48-carried byvwalls l2and 43 Irespectively...has the `worm wheel y secured .thereto and also ya :pinion 49.

This pinion 49 meshes'with .andndrives-.gear 50 splined to shaft ilfwhich is jour- nalledfin twobearings 52 and 53 carried respectivelyby the `vvalls 42 .and 43. The

fgendxofshaft 5l'feXtendir1g beyond bearing 53 has anfanchor plate-'or disci-54 .secured thereto, tov

-whichfthezcam .55is bolted. .The working, .pe- .ripheral surface -56 ofthe. cam is 'engaged by the .camffollotver ZiQtandzthe carrier. The contourof .the workingsurfa'ceof cam `55 .is shown by Fig. 5.

The-.means :For urging'zthe'carrier ,so that `the cam follower-Sthereon is-.maintai-nedin con- '.'stant-.engagement with-.the working `surface 56 `of tl'zcam..55comprises fa -uid pressure device-5) l .andrai lei/'enti :actuated thereby. To compensate .fof .varyng' weight .of the :carrier and. its ,equipvrment.it,sometimesgis.necessary 4to change the one ofQthese/holes maybe inserted/a bolt Whichis I threadedlyreceited byaanyfone. .ofthe threeholes tween the radial lines c and ydfis a gentle rise pushing the cam follower against the countervacting force of described.

3 shown in Fig. 1, the pivotal bolt which attaches the lever to the frame extends through the hole 63 in the lever and is threaded into the hole 66 of the frame. This makes the oppositely disposed portions of the lever substantially equal.

The fluid pressure device 60 comprises a cylinder l removably attached to the cover ll of the frame, in which cylinder there is provided a piston having a rod l2 which extends outside the cylinder 'IU and swivelly engages a recessed end of lever 5l. the abutment 28 of block 2B, substantially in the plane of the gibs or slideway upon which the carrier 22 attached to block 2B, maybe reciprocated. When the device 69 is energized, that is, when fluid under pressure is introduced into the The other end of said lever engages cylinder l0, the piston and its rod 'l2are urgedy ,supported thereby. Thus the cam follower 29 on the carrier is constantly urged into contact with the working surface of the cam 55 by the lever 6l. l

The Fig. 5 shows the contour of the cam in its normal rest position in which the fcam follower v29 assumes the positions H. ,In this position the lug 80, formed integral with or secured to the cam, lies directly in the path of movement of 'the cam follower 29 and thus, if the fluid pressure device 69 is deenergized at this time and: therefore eliminates the supporting function of the lever 6 l, the carrier and its attached elements will be prevented from dropping inasmuch as the cam follower 29 on the carrier will engage with and be supported by this lug. As the cam' n55 is rotated clockwise (Fig. 5) the cam follower 29 rides over the cam surface 56a to the point where the radial line a intersects the cam surface 5f during which time and in response to such movement of the cam follower, carrieris quickly moved downwardly a predetermined distance away from its normal rest position and toward the workpiece to be processed, The cam surface 56h, extending from the radial line a to the radial line b progressively moves away from the center of the cam so that, as the cam follower traverses this portion of the cam surface the carrier is moved gradually toward the workpiece to .be processed, at a definite rate and for a predetermined distance. As soon as the cam. follower passes the plane of the radial line b, it will roll along the cam surface 56e which is an abrupt step-olf toward the center of the cam. Now the fluid pressure device acting through the lever Sl, moves the carrier and its accoutrements upwardly toward its normal rest position, this quick return of the carrier terminating when the cam follower reaches 4the cam surface 56d at the radial line c. The cam surface IElid bethe lever 6| for purposes to be The end of shaft 5l extending beyondthe gear r5G is splined to receive the lever 85 lwhich may be placed upon the shaft in one of several positions rotatably, to vary its angular relation relalever 8B and concentric with shaft 5| receives a clamping bolt 88 the headed end of which extends through an opening in lever 85. Thus lever 86 is rotatably adjustable relatively to shaft 5| and may be secured in such adjusted position by clamping it to lever which is splined to shaft 5l. Lever 8B, when rotating ',with shaftl engages the rod 89 to open the limit switch 90 and thus break the lcircuit through the holding coil (not shown) of the circuit controller 94 thereby causing said controller to break Athe .circuit to the prime mover or electric motor 40 and stop its operation. A button 95 on the 'controller 94, when pressed closes the circuit vswitch Si] is secured to the frame cover 'Il in any V'suitable mannersothat'its actuator rod or member 89 may be engaged bythe lever 86 and moved thereby. The limit switch is opened to stop the operation of the motor 40 when the cam follower 129 substantially reaches the position on the cam in the plane of the radial line b so that as the motor coasts to a full stop after being deenergized by the breaking of its circuit, said cam follower 29 willvride down the cam surface 55C `underthe effect of the fluid pressure device and its lever 5l. When reaching the position in the plane of radial line c (Fig. 5) the cam follower rides on the cam surface 56d which, as has been lmentioned-is of gentle rise, thus the cam follower 29, in moving to the position H, is moved Aoutwardly against the force of the lever 6l. This cam follower movement occurs while the deenergize'd motor 40 is coasting to a stop, the counteracting forces all effecting a braking effort upon the motor which assures a' full stop thereof sometime while the cam follower is riding the cam surface 56d. Now, as has been described. the lug 88 isdirectly in the path of movement of the cam follower 29 thereby providing a support which is engaged by and which prevents dropping of the heavy carrier and its accoutrements in the event the fluid pressure de- 'vice is deenergized and does no longer provide the supporting force exerted upon the carrier 22 through the lever 6 l.

The type of cam used in the present invention that is, a cam whose outer peripheral surface is the working surface, offers the minimum of resistance and friction and thereby permits the use to easy sliding and eliminates tilting which would increase friction. .This also contributes to the use of a comparatively smaller motor for actuating the carrier.

By adjusting the pivotal connectionvof lever 6l to frame 20 a variable leverage may be obtained substantially to maintain the preferred ratio between theforce exerted by the fluid pressure 'device and the weight of the carrier and its equipment. L

In order to obtain different speeds of the proc- 'fessing tool, especially a' vdrill'or similar device H rotated bytheshaft 26, the ,operator may replace one train of speed reducing gearing '25 with another suitable for the requirements. To change the feed speed, the gearing between the motor 40 and the cam driving shaft 5I may be altered. Various types of cams 55 may be secured to the shaft 5| to suit ang7 condition. The machine is designed to make the said gearing easily accessible and changeable.

The interior of the frame 20 is suitably reinforced with ribs to withstand stresses and eliminate fractures when the machine is used for heavy duty work. The frame has a base portion |00 which is adapted to be secured to any desired foundation and especially to the well known rotatable indexing table upon which a plurality of these machines may be mounted each to do a speoic processing job at a particular station in the rotating path of the table.

While the embodiments of the present invention as herein disclosed, constitute a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A safety device for apparatus consisting of a reciprocative carrier held in operative engagement with the outer contour of a rotating cam by a power actuated lever whereby said carrier is moved in one direction by said lever, under the control of the rotating cam and moved in the opposite direction by the cam itself against the effect of said power actuated lever; and a detent operatively connected to the cam and held thereby in the path of carrier movement while said cam is in normal rest position, whereby automatic movement of said carrier is prevented when said lever is rendered inoperative while the cam is in normal rest position.

2. A safety device for a vertically reciprocative carrier comprising in combination, a rotatable cam; a pivoted lever; power means operative to move the lever into engagement with the carrier and urge said carrier into operative engagement with the cam whereby movement of the cam permits movement of the carrier by said lever in one direction and movement of the carrier by the cam in the other direction; and a supporting block on the cam and maintained in the path of carrier movement when said cam is in normal rest position, said block preventing dropping of the carrier when the power means is rendered inoperative while the cam is at rest.

3. A safety device for a vertically reciprocative carrier comprising in combination, means operative positively to actuate said carrier in both directions said means consisting of a rotatable cam and a power actuated lever urged into constant engagement with the lower side of the carrier, the cam actuating the carrier downwardly against the effect of said power energized lever and the lever actuating said carrier` upwardly against the cam; and a detent movable by said cam into the path of carrier movement and maintained in said position while said cam is in normal rest position, whereby dropping of the carrier due to deenergization of the lever while the cam is in the rest position is prevented.

4. A safety device for a vertically reciprocative carrier comprising in combination, means operative positively to actuate the carrier in both directions said means comprising a rotatable cam and. a lever yieldably urged to engage the carrier and lift it into operative engagement with the cam; means operative, when energized, for urging the lever to lift the carrier; and a detent integral with the cam and moved into the path of carrier movement during a portion of a revolution of said cam, said detent preventing automatic downward movement of the carrier while the cam is in this position and the lifting effect of the lever is discontinued by rendering its energizing means ineffective.

LAWRENCE WILLIAMS. EDWARD J. VOSLER..

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

UNITED STATES PATENTS Number Name Date '128,226 Hargroves May 19, 1903 1,850,299 Watson Mar. 22, 1932 1,950,597 Corwin Mar. 13, 1934 1,951,093 Johnston Mar. 13, 1934 2,054,018 Gilchrist Sept. 8, 1936 2,114,013 Ball Apr. 12, 1938 2,391,702 Hill Dec. 25, 1945

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