US1877314A - Cyclic limit mechanism - Google Patents

Description

Sept. 13, 1932.

. F. A, HERBERT 1,877,314

QYCLIG LIMIT MECHANISII Filed, May 2a. 1930 s Sheets-Sheet 1 gimme F; A. HERBERT 1,877,314

CYCLIC LIIIT IBCHANISI Filed lay 28 1950 5 Sheets-Sheet 2 Sgpt. 13 1932.

P 1 1932- F. A. HERBERT 1,877,314

CYCLIC LIMIT MECHANI SH Filed May 28, 1930 3 Sheets-Sheet 5 gvvuwntoc Patented Sept. 13, 1932 .FRANK A. HERBERT, on CINCINNATI, orrio cYcLIo LIMIT MECHANISM Application filed May as, 1930. s rial Noi-456,4611

The present invention relates to a cyclic multiple limit mechanismandisespecially adapted to use with an extension-table of the automatic leaf shifting type.

- An object of the invention is to provide control means for a pair ofoppositely reciprocating members whereby such members may first be pulled apart and halted at a primary limit, then retracted partially and then pulled apart to a second limit and then retracted to the initial position for repetition of the same cycle of operations.

The device of' the'invention. accomplishes these and other objects by the means described herein and disclosed in the accompanying drawings, in which:

Fig. 1 is a bottom planview of an extension table embodying a device-of'the invention, part being broken away;

Fig. 2 is a view taken online 22 of Fig. 1'.

Fig. 3 is a view similar to Fig. 2"but showing the table i'n its first opening position with-the device of the invention limitingsaid opening-movement.

Fig. 4 is an enlarged-fragmental view taken on line 44: of Fig. 3. A

Fig. 5 is an enlarged perspective view of the device, of the invention mount'ed'upona fragment ofthe table shown in Fig. 1'. i

In describingthe usefulapplication of the device of the present invention an automatic leaf. shifting extension table-i s'usedas an example, the invention being however not liinitedto this specific use as Will'be readily appreciated.

The'automatic leaf shiftin'gtable'will be briefly, described' so that a-clear idea of a typical cycle of'operations of the limit stop will be. had. The table structure comprises generally a frame structure which carries a pair of'shiftable table'sections and an extension leaf allhaving certain predetermined relative movements, which when precisely earriedout, separate the table sections, raise the normally submergedleaf to the plane of the table sections and'then join the leaf and sections; and bya subsequentse-ries of" operationsseparate the table section from-the leaf, submerge the leaf and *therr-j'oin the sections over thesubmerged' leaf: With u a UNITED STATES PArEurfopmcs Y means such as is provided by the present'invention these operations require care and skill; and failure to properly execute any of thenecessary movements requires the opera-' tor to begin all over again. i 5

Referring to the drawings the table "con- 4' sists' of a frame comprising'spaced bars-1O which carry the legs 1-1 and which are con nected together by a cross. board-12 There are two identical structures associated withthe'members lO so that a description of'one will serve for both. The frame and legs support the table structure and they do not move in spreading, the table to enlarged position.

Each member carries a freely rotatable gear 13 and has slide grooves 14 and 15 in its opposite sides. A splined or'reciprocat ing. slidable connection to the two table top sections 16and'17 is-had by the slides '18 and i 19 respectively, which carry keys 20 disposed 37 in thegrooves li'and 15. ,Slide18'is secured to top section 16-a'nd slide19'is secured to top section 17, by any means such as screws 21' being used to mount the slidesand spacers 22'to the underside of the top sections. Each I ofthe slides 18 and 19 have racks 23 secured f totheir bottoms for engagement with gears 18. Thetop sections thusmove uniformly in opposite directions relative to the frame structure and are guidedin the grooves by the slides, I

An extension leaf 24' normally rests be neath the overhanging and'meeting portions of'the topsections and is'so mountedand arranged that when the topsections 16 and 17 are pulled aparta given distance, the exten+ sion leaf 24. is raised bodily to the plane of the top sections'whichmay then be pushed together to forman enlarged table top with the leaf 24 between them. The means where by this is accomplished comprise bars 25 and 26'disposed close to the ends of the leaf: 24 and is secured thereto .by screws 27. An 0E- set roller 28'projects outwardly adj acent each endof bars 25 and 26 and cooperates with a raising and'loweringcam 29 mounted onthe flanges 30 of the top sections. springv urged hingedly mounted lifting. member 31 is secured by spring hingest32. and normally urges the extension leaf 24Eupwardly and astions are separated at predetermined distance and the edge 36 ofthe then perpendicular member 31 holds the extension at the proper level so that dowels 37 and holes 38 on the" top section and extension will mate when the top sections are pushed together? In order to retirethe extension 24 to its. submerged position as in Fig. 2, the top sec ,tionslfi and-1? are now spread apart to a greaterdistance than before in order to have spring hinge leaf 39 on member 31 permit a stud 40 (see Fig. 4) to first turn the leaf and pass beyond it so that upon movement of the top. sections toward each other the stud will abut leaf 39 which' can not be moved in the opposite direction. The force applied to the top sectionsnow causes the stud to bodily depress me'mber 31and relievethe extension whichnow descends gradually underthe influence of rollers 28 on cams 29 andthe top sectionszare then pushed into abutment.

V The structural details just set forth form no part' of the present invention which is concerned with a control or cyclic progressive limit-mechanism for a series of manual movements necessaryto properly operate a device such as the previously described table without-the exercise of any particular care on the part of the operator. r V p Attention-is now directed to Fig. 5 wherein the cyclic progressive limit stop is shown arranged forsuccessive movement of the table 'top sections at two different limits which are vital t0 the operativeness of the previously described mechanism. .The stop mechanism of the present invention consists essentially ofa plate 41 pivoted adjacent one end at 42 to: raise and lower in a vertical plane (see Fig.2) within limits defined by a slot 43and a fixed pin 44. Extending from the exposed face of the plate is .a cam track 45, and a curvedstop 46 spaced from and curved about andover the track 45. At the end 47 of the plate is an end stop 48 which continues along the top edge of theplate to form a track 49 which overhangs the. stop 46 and the major portion of track 45. A gravity actuated gate track 50 is pivoted on plate 41 for movement from its normally pendant position to contact the tapered end 51 of track 45 to provide a continuous track section against which a lug such as 52,"(see Figs. 2 and 3) fixed on cross board 12, may ride, thereby lifting the plate 41bodily and, asthe plate is moved with the slide 18, disposing lug 52 beneath track 45. Continued'relative movementcauses the lug '52 topass beyond the end 53 of track 45 whereupon the lug engages the stop 46. This the gate track 50 from turning so that the lug 52 on the frame'rides along the under curved face of stop 46 and out of the way or passage 54 between the stop 46 and end 53 of track 45 whereupon the plate 41 drops bodily about its pivotal mounting 42 until the track 49engages it. At this time the table has the extension. leaf 24 sition.

When theleaf24 isto be submerged and the table again reduced to its original length, the top sections are merely pulled apart again,

this time for a greater distance than, before, so that the leaf retlring mechan sm may op crate. The top sections are merely pulled apart untilthe lug 52 ridingbeneath track 49 engages the stop 48. Then the sections are pushed together allowing the lug 52 to ride in an operative poback beneath track 49 to the end 55 when plate 41 drops by gravity to its limit and the lug52 strikesgate track 50 andswings it aside until the parts assume the position shown in Fig. 2, when'the table is completely closed. At this time the device is conditioned to repeat thecycle of operations.

. It-isto be noted that the device of the invention, because of its convenient position in a vertical position in the practical embodiment shown, may employ the force of gravity. Otherforce s, e. g. spring force, maybe resorted to in orderto normallydispose the partsin the position shown in Fig.2, if it should be-found desirable to dispose the plate t 41 horizontally. In most instances it isdesira-ble to use a metal mounting base 56 to carry the plate 41 andgate track 50 and Sim: ply fasten the base, as byscrews 57 ,to a convenient surface. When mounted in this way the device withstands hard usagezwithout loosening or displacement.

I The deviceof the'invent on may be made in various sizesand the spacing between stops 46 and 48 and gate track 50 will beunderstood to be varied according to the difference between the progressive limits ofmovement of the reciprocating or movable members to V be controlled thereby. A lug or stop 58 may be provided on the plate 41 in order to prevent completely around on its pivotalmounting. I

. What is claimed is 5 1., The combination with a pair'ofmembers having relative reciprocating movement of acyclic limit mechanism comprising a pivoted plate ,havingspaced stops thereon, a

track portion connecting with one of the V stops, a track portion adjacent and in noncontinuous relation to the other of said stops,

a gate track movable to a position of continuity with the last mentioned track portion, said mechanism being mounted on one of the reciprocating members and a lug on the other of said membersandextending into the path of said stops. y

2. A cyclic progressive limit stop mechanism comprising a pivotally supported plate, spaced stop members on one face of the plate, a track section continuous with one of the stops and overhanging the other of said stops, a second track section on the plate discontinuous with the second mentioned stop, a gate track mounted for movement over the plate to and from substantial continuity with said second track section, means limiting pivotal movement of the plate and a lug mounted in fixed relation for engaging said stops.

3. In a device of the class described the combination of a plate mounted for limited pivotal movement upon a given sliding member, a lug fixedly mounted on a second nonmoving member, a gate track member mounted on the plate in the path of said 'lug and movable thereby, a track portion on the plate, limiting movement of said gate in one direction and adapted to form a continuous track with said gate, a stop adjacent one end of said track and spaced therefrom to form a way through which the lug may move from the bottom face of the track to a position above said track, and a second track portion on the plate overhanging said first track and extending beyond the track and stop and having'a turned portion constituting a second stop.

4;. The combination with a pair of relatively reciprocable members of a cyclic progressive stop mechanism comprising a plate pivoted to one of the members for limited movement thereon, a pair of spaced stops on said plate, a track portion connected with one of said stops, a second track section disposed adjacent but disconnected from the other of said stops, a pivoted track member movable to provide at times a continuation of the second track section and a lug upon the-second member, the plate being movable with its associated member to engage the lug to swing the pivoted track member to permit the lug to ride beneath the second track to the second stop, then, upon retraction of the plate causing the lug to circumvent the second stop and I engage the first track and its associated stop.

5. The combination with a pair of relatively reciprocable members of a lug on one of said members and means on the other of said members comprising a pivoted plate with spaced stops and fixed and movable track sections for cooperating with the lug to control the limits of reciprocation of the members so that the members may move a given distance only, then upon partial re.- traction be moved to a greater distance and larcycle of movements.

6.'In combination a movable relative to the lug, a plate pivoted thereon and'having a'transverse slot,a,pin in the base extending into the slot for limiton the plate comprising a plurality. of spaced stops and track sections whereby the plate may successively be halted by each of said then retracted to original position for a similug, a b ase member I ing pivotal movement of the plate, an'dmeans' stops'as they engage the lug and then returned to its initial position. y

' 7. The combination with an extension'table having an extension lea-f arranged to be raised to and lowered from operative'position by mechanism operated bypredetermined opening and closing movements relative to a table supporting frame, of means comprising a lug on the supporting frame and a cyclic progressive limit mechanism mounted'on a relatively reciprocable portion of the table and comprising a shiftable plate, I

spaced stops on the plate and fixed and movable cam track sectionson the plate for cooperation with the lug. I 8. In a 'device of the class described the combination of a shiftable plate, a movable cam track section thereon, a pair of spaced track sections one of which may connect with saidmovable section, a primary stop curved about an end of one of sald track sectlons and spaced therefrom and a final stop con nected to the other of said track sections, and a lug fixed adj acentthe shiftable plate and cooperating with said tracks and stops to ef feet a multiple of limits of reciprocation o the shiftable plate.

In testimony whereof, I have hereuntosub- 7 V scribedmy name this 7th day of May, 1930. FRANK A. HERBERT.

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