US2719745A - Take-up latch mechanism - Google Patents

Description

Oct. 4, 1955 G, R, KENT ET AL TAKE-UP LATCH MECHANISM Filed Jan. 24. 1952 #nml United States Paten-t LATCH MECHANISM Application January 24, 1952, Serial 'No. 268,084 6 Claims. (Cl. 292-112) This invention relates to a take-up 'latchmechansm Itis an object .of this invention -to provide a novel vand highly eicient positive take-.up latch mechanism adapted to forcibly close two sectionsof a casing from .partially open position to tightly closed clamped rtogether position.

It is another object to provide a `take-.up latch mecha.- nism having an elongated longitudinally shiftable take-np member adapted to be forcibly shifted from Y'fully projected to fully retracted position and positively .closea pair .of .casing bsections from partially .open ,to tightly closed and clamped together position.

More specifically, it is `an obiect tozproyide a longitudinally ,shiftable takefup member having a toothedrack with Yan .enlarged recess formedat the low/er endzthereof and a rotatable cooperatively rtoothed aeulating and locking pinion `intermeshed with the teeth of said .takezup rack Ifor lpositively projecting ,the same fromfully -projected to fully retracted position, said pinion having .a locking cam formed .around a'portionof 4the periphery ,thereof to be received in the-recess at theflowerlend of the reciprocatedrack and engage the lower tooth thereof with alocking force :byan y,over center locking action.

These and other `objects and advantages of Ythis inyention will `more fully appear .'.from `the following .description made iu ,connection yviththe ,accompanying drawings wherein r,like reference characters refer to the same. or Similar parts :throughout the several yiews andin which:

Fig. vil is .a side elevational yiew .of thetake-.up latch mechanism with .a portion thereof broken away: u

.Fig.;.2;is1a rear elevational wiew thereofwiththe einer cover plate -relnoyed andshowing the reeipvroeated .takeup member in fully retracted locked position;

Fig. 3 :is e view similar 1 0 Fig- 2;.Sbowingat11e reciprocatedfmemherinpartiallynroieetedrosit .11;

Fig. 4i S vertical sectional Yiewshowing thertalrezup latch mechanism as mounted .on a photographie portable printing .device showing the eoverfin @mieux-raised posi-- doubs' dotted lines; and

Fig'. V5 is .a fragmentary front elevational view :thereof with ,the two easing ;se.otions.i111tightlyfelamp.esl together position- As illustrated :in the accompanying drawings, awe provide a casing for a port-able photographic pr-,i ine appa- .ratus such as :is disclosed in the application entitled 'Device for Acurately Exposing Sensitized jRlateS. ,tiled lune 1:5. 1951, Serial No. 231,792, and requiring that the upper section and 'lower section ofthe casing be tightlyelamped together to produce positive contact between the surface area of ka sensitized plate and the negtaive through which the same lis to vbe printed. -Such a photggrapliicprinting device is illustrated vin Fig. 4 andlh'as `a-lower section `8, an upper section 9, a pressure-applying and equalizing bag in the lower section, and a light source 11 in the upper section. A transparent pressure plate 12 mounted across the bottom of the upper section positively engages the top surface of the pneumatic bag 10 and a photographic negative 13 through which a sensitized plate 14 is to be printed. A lifting handle 15 is fixed to the front 2,719,745 Patented Oct. 4, 1955` end portion of `the upper section 9 -and a xed .catch member -16 isisecured to -the central portion of the lower section 8 at the front edge thereof.

Our take-,uplatch mechanism, designated as an entiret-y :'by the fletterA, is mounted directly above the fixed catch i16 and is `secured to .the front portion of the upper section 9. 'Theltake-up latch'has a body 17 with a milled upstanding groove formed in the outer portion thereof and in :which the'upper' portion of a reciprocated elongated .toothed take-up 4member is slidably mounted and is designated'by the numeral 18. A rotatable pinion l19 is ournalled in said body member and 'has a plurality of spaced teeth around only a portion of the periphery thereof. AA locking cam v2 1 is `formedaround the remainder of rthe periphery, -as ibest shown in Figs. 2 and 3. The -teeth :18a `of the reciprocated take-up member v18 form a rack along :the vedge thereof :adjacent the pinion 1'9 and the. teeth ,20 ,of the pinion 19 .are intermeshed with ,the Vteeth 1:18a of said rack. A recess 18b is formed at fthe v-bottom of the rack and is adapted to receive the cam 21 when'the yteeth 20 ride off of the rack 18a. The

x cam .2i engagesthe lowermost tooth of the rack to securely locki-the recprocated 'latch member 18 in upwardly retracted position.

vA resilient spring member L22 .urges the reciprocated latch member downwardly to vmaintain engagement of the teeth `18a=.with the cam .even though -no pressure 'is exerted :to .open the casing, thus positively intermeshing the teeth vof -the rack with the teeth 20 of the pinion when the k.cam 21 is rotated downwardly out of the recess. A vcover plate, best lshown in Fig. 11, .enclosesfthe groove ,in iwhich the `reciprocated vtake-up member is shiftabl-y mounted. This voverplate lis designated by the numeral 23';`ar1dfisysecured to the outer face of -the body 17 vasby anyfsuitable means such as the screws 24,bes't shownin iFig. 1. The `inner surface of said cover plate is grooved out intopposed vrelationto the guiding groove for Athe'takefnp` member 1-8 and said groove 'in the cover plate -23 fis `cleeper'at :the lower end thereof than at the upper `end, fas -best shown in 'Fig. l, `and thuspermits the lower .end :of ltheelongated take-up member .to swing outwardly .and-form ;a spring latch mechanism in .combination with the .fixed -catch .16. Any vsuitable means for -resiliently furging said member V18 inwardly 'may-tbe pro.-

, vided lauch as rthe compression spring 25 interposed 'between `therouterface of member `18 and the opposed por- .tion iof'thewedge'shaped .groove formed in cover -plate 23, whichV groove fis designated vby the numeral"23a. The zlower portion .of the reciprocated take-.up member r18 has a 'cooperating intertting latch element '18e with 'a recess''lSd formed'immediately therea'bove. The catch 16 thas a .dxed vlatch element V16a formed fin the yupper portion thereof and is adapted to :be received in recess 18d when ethe latch element 1-8c 'is lmoved downwardly -therebelow'to 'intert' therewith.V 'The Lengaging locking surfaces of the cooperating latch elements 16d and 18e are beveled to form a tightly wedged .connection therebetween-vvhen1.u-pwardlydirected pressure is applied to take-up imemberll. "The upper end portion of. the catch 16 l`fand the ilower 4end portion .of :the 'latch element 18e are* Ibeveled to :produceV lengaging camming :surfaces .adapted to shift lthe 'Flower portion of .member 18 `outwardly whereby the flatchvelement'. .'iSczrides downwardly .over thecooperating latch .elementim An `actuating ,shaft 26 is Xed atlone end =to pinion 19 and `#hasnsuitah'le(gripping lmeahssuch as [the turning 'knob 27 fixed to the outer end thereof as by a set screw 28. A gripping knob 27 has a pair of outstanding gripping arms 27a to assist in forcibly turning said pinion 19. A suitable pair of stop elements 29 are respectively fixed to the inner portion of knob 27 and the outside of cover plate 23 through which shaft 26 extends and in which said shaft is journalled. These stop elements 29 limit the rotation of the knob 27 to substantially one complete revolution. Obviously, the teeth of the rack and pinion are of such a pitch that one complete revolution of shaft 26 is more than sufficient to fully retract reciprocated latch member 1S from fully projected position.

The casing for the photographic printer, shown in Fig. 4, is one example of a housing or enclosing unit requiring a take-up type of latch mechanism and in the operation of this particular device the pneumatic pressure bag is inated to a degree requiring compression of the air therein to close the two sections 8 and 9 together. in this way the photographic negative 13 and sensitized plate 14 are tightly clamped together over their entire engaged surface areas by the pressure of the glass pressure plate 12 against the top thereof. When thenegative 13 and plate 14 have been placed on the bed formed by the pneumatic pressure bag 10, the top cover 9 is lowered into engagement with the negative and a rolling action from the hinged interconnectededges of the two sections 8 and 9, such as that described in the previously identified co-pending application, is produced. Suicient downward pressure is applied by the operator to engage the two latch elements 16a and 18C into interlocked relation with the take-up member 18 in fully projected position. When the latch element 18e has ridden downwardly over the outer surface of latch element 16a and said element 16a has been received in the recess 18d of the take-up member 1S, the knob 27 may be rotated in a clock-wise direction as viewed from the front (Figs. 2 and 3 are rear views of the rack and pinion mechanism) to forcibly move the take-up member 18 upwardly and tightly clamp the two casing sections 8 and 9 together. When the teeth 20 ride off the teeth 18a of the take-up rack, the locking cam 21 engages the lowermost tooth 18a of the rack and positively locks the same to hold the take-up member 18 in fully retractedvposition and the stops 29 limit the rotation of the pinion 19 before the cam 21 rides upwardly off the lowermost tooth 18a.

It will be seen that we have provided a novel and highly etiicient take-up latch mechanism for forcibly closing a pair of hinged sections or the like through the use of a rack and pinion to impart the take-up movement and a locking cam formed around a portion of the periphery of the pinion to positively engage the lowermost tooth of the rack and ride upwardly thereon to securely hold the take-up member on which the rack is mounted in upwardly projected position. By mounting said member 18 with freedom for outward shifting movement of the lower end portion thereof against the yielding force of spring 25, a spring latch mechanism is produced which snaps into interlocked position when the latch element 18e has ridden downwardly over the fixed latch element 16a.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope of this invention which, generally stated, consists in the matter shown and described herein and set forth in the appended claims. l

What we claim is:

1. A take-up latch mechanism adapted to engage a fixed catch on one of a pair of hinged casing sections, said take-up latch comprising a body member provided with longitudinal guiding means, an elongated reciprocated take-up member shiftably mounted in said guiding means, a catch engaging latch element mounted at the outer end of said take-up member, a toothed rack fixed along at least one edge portion of said take-up member, a rotatable pinion journaled in said body and having 4 the `teeth thereof intermeshed with the teeth of said rack to forcibly reciprocate said take-up member into and out of take-up position, and a locking cam shiftably mounted in said body for engaging said take-up member when the same is in extreme take-up position to securely hold and lock the same.

2. A take-up latch mechanism adapted to engage a xed catch on one of a pair of hinged casing sections, said take-up latch comprising a body member having longitudinal guiding means formed therein, a reciproeated take-up member shiftably mounted in said guiding means, a catch engaging latch element fixed -at the outer end of said take-up member, a toothed rack fixed along one edge of said take-up member and having an enlarged recess formed at the end thereof nearest to said latch element, a rotatable pinion journaled in said body and having spaced teeth formed around only a portion of the periphery thereof intermeshed with the teeth of said rack, a locking cam formed around the remainder of the periphery of said pinion and positioned to engage the outermost tooth of the rack when the teeth of said pinion have ridden olf therefrom and said cam has been'received in the recess at the end of said rack, and means for controllably rotating said pinion.

3; The structure set forth in claim 2 and stop mean associated with said latch mechanism for limiting the rotation of said pinion to substantially one complete revolution. f

4. The structure set forth in claim 2 and resilient means for normally urging said take-up member into outwardly f projected position to maintain engagement between the teeth of the rack and said pinion to cause meshing of the teeth of'the pinion and the rack when said cam has passed out of `engagement with the outer tooth of the rack.

, 5. Atake-up latchrmechanism adapted to engage a fixed catch on one of a pair of hinged casing sections, said take-up 'latch comprising a take-up member with a catch-engaging latch element at the outer end thereof, actuating means reciprocating said latch into and out of take-up position, locking means positively holding said member in take-up position, guiding means for said take-up member constructed and arranged to permit movement thereof in a plane generally normal to the direction-of reciprocation of said take-up member, resilient means normally holding said take-up member lin latching position but permitting the same to ,shifty into a catch engaging position to Vproduce a spring latchoperation. f

6. AV rack and pinion take-up mechanism comprising a reciproeably mounted member, a rack carried by'said member, a pinion having spaced teeth-around only a portionof Vthe periphery thereof to intermesh 'with1 the teeth of said rack, a locking cam formed in the remain'- ing portion of the periphery of said pinion and engaging the tooth at the outer end of said rack when the teeth of 'said pinion have passedltherebeyond to positively lock said reciprocated member in take-up position, and resilient means urging said take-up member outwardly into projected' position to. intermesh the teeth thereof with the teeth of said pinion when the cam'hasridden out of engagement with said outermost rack tooth.

References Cited in the tile of this patent UNITED STATES PATENTS 383,549 Wolcott Mayvz'gfisss 1,290,462 Wuhan 1an. 7, k1919 2,378,654 l y Pekny Innen, 1945

Images