US2665154A

US2665154A - Latch bolt unit

Info

Publication number: US2665154A
Authority: US
Inventors: Hagstrom Gotthard
Original assignee: SAFE PADLOCK AND HARDWARE COMP
Current assignee: SAFE PADLOCK AND HARDWARE Co; SAFE PADLOCK AND HARDWARE COMP
Priority date: 1950-08-11
Filing date: 1952-02-14
Publication date: 1954-01-05
Anticipated expiration: 1971-01-05

Description

G. HAGSTROM LATCH BOLT UNIT Jan. 5, 1954 Original Filed Aug. 11, 1950 ATTORNEY Patented Jan. 5, 1954 ATCH. OLT

Gotthard Hagstrom, Greenwich, Gonm, assignor d h Safe Padlock a d; Hardware. Qomnan i Lanc ster, Ba, ,1- asrion ofi Be nsy vauia O a application August 1.1, 195 Se i l Nu-i 178,897, how Patent No. 2,644,7(14; dated July 7, 1953. Divided and this application Februar-i- 14, 1952,4Serial No. 271,492

11 Claims. (01. 292 7-163)" This invention relates to. certain improvements in t h ol unit nd the nature; an objects f he inv ntion will be readily r co ni d by thos l d i the rts invo ved n: th ght at th t l o ins p anati and detail d de rin t on of the acs mpany s dr w na il u tiret a what I no elieve to be the p e erred emh di= meri s or mechan ca expressions of the nventi n ir m am g va ou ther embod ment m difir eatiohs. var atio comb nations and ons r e tions of which the invention is capablelwithin the broad spirit, and. scope thereof as defined by the la ms hereto; appended:

This. applioationiisfiled as a division of my eon-t se ing applicati n serial. N 1 39.7, filed Au-. u t 1.1 1950. for Door- .Latch Me han m Pa nt NO, Mi -i3 4, i sued July 7, i953.

he inventionis par cularly ern d; w th h o called tubular latch bolts fo install ti n and m un in in a m i ad; o b ed p n n formed in a closure such, as a door, Such latch bolts usually f r unit wh ch comp ise a case. within which is, housed a spring; loaded latch bolt for projection to latching position by the biasing; -s on of. its. pr ng loa ing and forret a n t un'latohed; position against, its snring loading, M anism i inc ud d w h n the ase for aetuation to retract, the latch boltwhilethe' association of. such m chan sm and the a h lt i usually such that the bolt nay be depressed to retractedposition independently of the retraoting mechanism,

I is, an obje t at my invention to pr an impro ed d si n andc u truct on of. tubu ar. latch bolt unit. capable of general use with various types of do r la ch nd 100k m hani m a d e sooalled door look sets formed therewith.

A other objec is o r v de a tubular at h b unit adaptedfor neral u e as a. plain unit of the p n e a tua ed, type a well as ing ad p e for afiisi n use with various nee a ty es of. do r at-ah mechanisms, such, f r exa mole, the inside door set is l s d in my afore aid patent.

A fur he obj ct to p ov e a de ign nd construction Qf tuhulat latch bolt unit which can e readily m nufa tured in quant ty pr duct on at, low o t yet whi h will insu e p siti e. p ci io op ra io oi he un w h a minimum o mai tenan and ruc ural o p rati nal fa lurea under the arious cond on t which. sub jected in o erati n and.

, Another ob ct s o pro ide a u ar case for la ch b.0 2 unit o a sonstrustio which has a m nimum of p rts of. character to be read ly tamped or formed and. re d ly a curately as sembled for low-cost quantity production,

A u t erb ect i to provide such a case de: ig d 5 3 co erative m unting therein in opera a-tive assembly; the; components. of the. latch, bolt r traa ns. me hanism for; functioning; of}; such mechanism with minimum friction. yet withlpreoia n. under ll no mal operatin conditions.

A da ur er o ject. is to. provide.- an improved and s mplifi d: c stituction and assem ly oftu= hula 6 mqunteddatohbolt retracting mecha: nism and of the latch bolt operatively assembled th with.

ith the fore oin and variQus other obi e features and, results in view which will be readily apparent fromlthe following detailed description and explanation, my inventioneonsists in certain novel features i d i n and construction, and in ombinations and suh sombinations of pa d elements, all as will be more fully referred to, and spec fied hereinafteri.

f rr ng to the aoqompanyin drawings. in which similar reierence characters refer to corre= no di s parts. throu hout the several: figures thereof:

Fig. 1 is aview in horizontal section through a latch b lt unit of the invention, in? mounted, in. stalled position in a. door in, operative; association with a door knob operated latch bolt retracting pindl i portiori only of. the. door being shown.

Fi 2 is a view in vertical longitudinal section taken as on th line 2: of'l ie. 1.

Fig. 3 is an exploded View illustratingin per--.. speotive the parts and components; makingeun the latch looltunit of the form of the example unit of Figs. 1 and 2, with the parts of the tubularease, the latch bolt and the bolt retracting mech-- anism being: shown separated but; in the relative positions thereof to he assumed in assembly.

Fig. 4 is a View in top plan of a portion of the unit, showing partie larly t e m unting of the bearing plate. and. rolibaok in the case.

A presentlynreferred orm and emb d m i a tubular e se latch hoit unit embodying the vari us ieatures of my invention ha been sea looted nd. s sslas here n by W313i of examp in operative installa ion and associat d w h 9 suit bl knob operated. astua n stain-die 0f" any suitable or d si d d or lo k: set but without any intention to limit the use of the latch bolt unit to such door lock set 9; in any other particular set. Referri g t Fi l and 2 of the drawings, a portion of a door 1.3. is iselosed in whi h a usual mortised or bor d passa e or space is formed which extends into the body of the door D. through the outer fir s edge 3; thereof. A tubular latch bolt unit L of the invention is mounted in horizontally disposed position within the bore 2 in operative association with a door lock or latch set which includes a spindle S mounted in position extended transversely through the door D and the latch bolt unit L. The door D is provided with a circular bored opening 4 which extends transversely through the door across and intersects opening 2 with the axes of these bores 2 and 4 being perpendicular to each other. It is the bore 4 which is provided for and through which the spindle S extends in operative association with the latch bolt unit L. The forward, outer end of unit L is provided with a vertically disposed face plate I'I attached to a back plate I secured on the forward end of the case of the unit L. Unit L is mounted in position in opening 2 in the usual manner by attaching the plates I05 and I0'I to the door edge by screws I0Ia, as shown in Fig. 2.

The spindle S is formed in this instance of square cross section (see Fig. 2) and is primarily supported in the example hereof in its horizontally disposed position at the central or intermediate portion thereof which extends through and is received in the latch bolt unit L in operative connection with the latch bolt retracting mechanism therein. The spindle S mounts at its opposite ends and the opposite sides of door D. The inner and outer door knobs I and 0, respectively, which are connected therewith in the usual or any desired manner to permit of the spindle S being rotated thereby in either direction by manual turning of either of the knobs. Any suitable outside rose I4 may be provided at the outer side of the door through which spindle S rotatably extends, and similarly a suitable inside rose I5 may be provided at the inner side of the door through which the spindle extends for rotation therein.

The latch bolt unit L of the example embodiment of my invention comprises a case I00 which may be stamped, pressed or otherwise formed from a suitable sheet material to include a side wall IOI, opposite edge, parallel walls I02 and I03 connected at one end by an end wall I04. In this instance the wall I02 is shown as the upper wall while wall I03 is the lower one and the wall I04 is the inner end wall of the case with the unit L in installed position in the door D. At the forward end thereof the case I00 is open and the walls I02 and I03 have at their outer end edges the upwardly and downwardly turned tongues mm and I03a, respectively, by which the case I00 has secured and attached to the forward or outer end thereof the vertically disposed back plate I05. This plate I05 is provided with a central opening I06 therethrough which with the plate in assembled position on the forward end of case I00 is aligned with the open forward end of the case. The complementary face plate I01 is suitably secured on and covering the outer side of the inner or back plate I05. The face plate I0! is provided with a rectangular opening I 08 therethrough which is aligned with the opening I 06 in the back plate I05. The aligned openings I06 and I08 in the plates I05 and I0'I are adapted to slidably receive therein the usual door latch bolt 99 for retraction and projection therethrough in the operation of the latch bolt unit L.

Case I00 is completed by the attachment thereto of a cap I09 which forms the side wall of the case opposite and parallel with the side wall IOI. The cap I09 at its forward end is provided with a forwardly extended tongue I09a by which it is secured to the back plate I05 and face plate I01 in the assembled position of the case. The rear end of the cap I09 is formed with a recess I09b adapted to receive therein a tongue I04a formed on and projecting from the free edge of the inner end wall I04. The tongue I04a fitted into the recess I091) attaches and positions the rear end of the cap I09 on the case I00 in assembled position thereof. The top wall I02 and the bottom wall I03 are each formed of reduced width intermediate their forward and rear ends to provide the elongated, longitudinal seating edges I 02b and I 03b, respectively. The walls I02 and I03 at their forward ends at the open side of the case which receives the cap I09 thereover, are formed to provide the projecting tongues I020 and I03c, respectively. Seats I 02d and I03d are thus formed by the edges of the walls I02 and I 03, respectively, which connect the tongues I020 and I03c with the elongated seat forming edges I02b and I03b. The walls I02 and I03 are provided with cut-outs H0 therein which are aligned transversely of the case I00 in positions located intermediate the seating edges I02b and N31) and the inner end wall I 04. Transversely parallel tabs I022 are formed from the walls I 02 and I03 between the cut-outs H0 and the inner ends of seating edges I02b and I03b, while at the rear sides of the cutouts IIO, Walls I02 and I03 are formed to provide the outwardly projecting tabs or tongues I027, respectively.

The cut-outs or recesses H0 in the walls I02 and I03 provide the similar transversely aligned seats IIOa, which seats are extended inwardly and forwardly by undercuts or re-entrant recesses to form in the walls the forwardly extended slots IIOb. The wall IOI and the cap I09 of case I 00 are formed with the circular openings III transversely therethrough respectively, which with the unit in assembled relation are axially aligned for receiving therethrough the latch bolt actuating spindle S.

The case side wall forming cap I09 is formed with the laterally offset, longitudinal edge flanges I 09c and the laterally offset transverse inner end flange I09d, in which latter flange the recess I091) is provided. The flanges I 090 terminate spaced from the forward end of the cap I09 and the cap is formed intermediate its forward end and the forward ends of flanges [099 with the opposite side, laterally extending tongues I09e and the opposite forward recesses I09 The offset longitudinal flanges I050 of the cap I09 are formed with the pairs of opposite transversely aligned recesses I09g in locations for receiving therein the pairs of case tongues I02e and I02 respectively.

In assembled position of the cap I09 on the case I00, tongues I02c and I030 seat in the cap recesses I09f; cap tongues I09e seat on the case seats W211 and IBM; the offset flanges I090 of the cap I09 seat on the elongated longitudinal edge seats I02b and I03b of the case walls I02 and I03, and extend rearwardly over and across the cut-out portions which form the inset seats IIOa; the case tongues I02e and I02 are re ceived in the cap recesses I09a, respectively, and case tongue IMa is received and seats in the recess I09b of the offset end flange I09d of the cap I09. The tab or tongue I 09a projecting from the forward end of the cap I09 extends through the opening I06 of the back plate I05, being engaged over the adjacent edge portion of that opening, while the tongues I02a and Ba of the case I00 also extend into back plate opening I05 5 and are engaged over adjacent edge portions of that opening.

The case closing cap I09 thus has in effect a snap attachment on and to the case I in assembled position thereof, so that it may be readily assembled on the case with the case assembled in attached position to the back plate I at the forward end thereof. The tab or tongue I04a may after assembly be bent slightly inwardly over and engaged with the cap to insure against cap displacement. It may be as readily bent outwardly sufiiciently to enable ready detachment and removal of the cap I09 from the case I00 in the event that it should become desirable to open the case for repair or replacement of any of the parts of the latch bolt mechanism contained within the case. The complete case itself comprises but two (2) readily manufactured major components, namely, the case I00 and the cap I09, while the latch bolt receiving and mounting structure attached to the forward end of the case I00 comprises but two (2) parts, namely, the back plate I05 and the face plate I 0'! which are easily manufactured and readily assembled on the forward end of the case.

The mechanism for retracting and projecting the latch bolt 99 is mounted and enclosed within the case I00 and cap I09, and in accordance with my invention such mechanism includes a a hub or roll-back mounting, bearing member II2. This bearing member H2 is provided with a circular bore therethrough and is mounted on the spaced seats I Illa provided by the cut-outs H0 in walls I02 and I 03, with such bearing member in position extending across the case I 00 between the wall I0! and the cap I09 with the bore H3 thereof axially aligned with the bores H0 in case wall IOI and in the cap I00. The bearing member H2 is formed with the opposite extended portions forming the flanges II2a which engage and seat upon the seats I I0 and at their forward ends are received and engaged in the slots formed by the undercuts IIOb respectively, in the walls I02 and I03. The bearing member H2 is formed or provided with the inwardly turned flange II I across the forward end thereof. This flange I I4 is formed curved or arcuate about the axis of the bore I I3 as a center. The effective length of this flange H4 is equal to the spacing between the inner surfaces of the walls I02 and I03, so that the flange will fit into position therebetween. A hub or roll-back member H5 having a square opening I I 6 therethrough which is dimensioned to slida'bly fit and receive therethrough the spindle S, is provided for rotatable mounting on and against the inner side of the bearing member II2. Hub member H5 is formed to provide the curved forward edge II1 complementary with the inner curved side of the arcuate flange H4 for slid-able bearing engagement with such flange. The curved forward edge II! of rollback member II5 has its opposite ends extended outwardly beyond the body of the roll-back member to form the upper and lower lugs H8.

A yoke member I 20 of generally elongated, rectangular form is slidably mounted and confined within the case it!) for actuation by rotation of the roll-back I 15 to retract and project the latch bolt 99. This yoke I20 includes a vertically disposed wali iZI having an elongated opening I22 transversely therethrough with this wall in assembled position of the yoke in the unit disposed and slidable between the inner side of rollback member H5 and the outerside wall or cap I 09, as will be clear by reference to Fig. 1. At its forward, upper side the yoke I20 has an inwardly bent guide and positioning finger I23 which has slidable engagement at its free end with the inner side of case wall I0 I. At its forward, lower side the yoke I20 is formed with an inturned flange I 2% which also has at its inner free end, slidable bearing engagement with the inner side of the wall IOI of the case I00. The flange I26 is formed with a rectangular openin I25 therethrough. The yoke I20 bridges the roll-back member H5 and the spindle S whichextends therethrough in assembled position, and at its rear end between the bearing member IE2 and the inner end wall I04 of the case I00, th yoke is bent inwardly for its full Width to form the flange I26 thereacross which has slidable bearing engagement with the inner surface of the wall IOI, and which together with the finger I23 and the flange I24 at the forward end of the yoke, provides the positioning and aligning support for the reciproctaion of the yoke within the case I00. The yoke I20 has lateral guiding support in the direction of the cap I09 by slidable engagement with the inner side, fiat surfaces provided by the portions of the cap contiguous thereto.

The yoke member I20 has formed and bent-up therefrom at the upper and lower side edges of the wall I21, the upwardly and downwardly projected ears I30, respectively. The ears I30 are located on the wall I2I intermediate the length of the elongated opening I22 and in positions at the rear of and engaged by the upper and lower lugs I18, respectively, of the roll-back member H5. Hence, in assembled position the rotation of the roll-back member H5 in either direction by rotation of the spindle S will cause the rearwardly swinging or rocking lug I I8 to engage its yoke mounted ear and to thereby force or slide the yoke rearwardly in the case I 00 in a direction to retract the latch bolt 99.

The latch bolt 99 of the latch bolt unit L may be considered to be of generally conventional design to provide the usual inclined face or surface for slidable engagement against the strike plate 8i (see Fig. l) of a door frame. In this instance, the latch bolt 99 is slidabiy positioned in and guided by the square opening I08 through the face plate I07, and extended inwardly through the opening I06 of the back plate I05 which is attached to the forward end of the case I80. The latch bolt 99 has suitably connected to the end thereof a tail piece Iv'iI which extends inwardly a distance into the case I20 and which is provided at its inner end with an upwardly projected nose forming a hook I32. The hooked inner end of the tail piece IEI extends into the rectangular opening I 25 of flange I2 1 of the yoke I20 in position with the upwardly extended nose of the hook I32 engageable against the inner side of the flange I24 at the upper side of the opening I25. Upon rearward movement of the yoke I20 within the case i00 the hooked inner end H32 of the tail piece I3I being engaged with the yoke will draw the tail piece rearwardly and retract the latch bolt 99. However, the latch bolt 53.; with the tail piece I3I is movable rearwardly relative to and independently: of the yoke I20 by rearwardly acting forces-applied to the latch bolt at the outer end thereof. Under such conditions the tail piece I3I slides freely rearwardly through 7 and over the tail piece 431 under compresison between the 'rear of'the latch bolt 99 and the flange 12! of the --yokemember 128. Thus, thelatch bolt when depressed or moved inwardly relative to th yoke l2il places the spring i33 under increased compression, so that upon release of the inwardly acting forces on the latch bolt the latter is instantly projected outwardly to normal strike-engaging, door latching position.

The yoke member I20 is spring loaded and normally continuously biased to its forwardly prodesired position. With the unit L of my present invention the spring loading of the yoke I'Z'O is provided by a coiled expansion spring I34 which is inserted under compression within the case l 90 between the inner end wall I01 of the case and the inner end flange 126 of the yoke I29. When the roll-back 115 is rotated in either direction by spindle :S which extends transversely therethrough in driving connection therewith in assembled position, the "yoke 2 8 is forced rear- 'wardly against the spring 434 and the latch bolt is retracted. Upon release of the turning forces on the spindle S the spring 134 acts to instantly move the yoke I20 forwardly to return it to normal, latch bolt projected position. When the latch bolt 39 is retracted by rearward movement of the yoke 12!! against the spring ltd, the spring 133 is not further compressed. However, when the latch bolt 98 is depressed and retracted independently of the yoke I20, the spring I33 is compressed and in order to permit of such compression spring I34 must not yield to the forces applied to the yoke by the spring I33. Hence, spring 134 is formed heavier to exert a force greater than that of the-spring 133, so as to be unyielding under such conditions.

By the foregoing design, construction and assembly I have produced a door latch bolt unit of extreme mechanical simplicity with a minimum of parts each of which may be readily manufactured by low-cost quantity production and which parts lend themselves to ready, time assembly with assurance of proper operative relation of the parts when assembled. With the twopart pressed or stamped case a light-weight structure is produced with close tolerances and without the need for expensive finishing operations. The case structure with its snap-on cover plate is readily assembled and disassembled, while providing an exteriorly clean case. The design and assembly of the case with the bearing plate mounting provided therefor, not only makes for ease of assembly but insures in a minimum friction and wear arrangement when assembled in operative relation in the case with the roll-back and the latch bolt retracting yoke.

It will also be evident to those skilled in the art that various changes, variations, modifications, substitutions, eliminations and additions might be resorted to without departing from the broad spirit and scope of my invention, and hence I do not intend or desire to limit my invention in all respects to the exact and specific disclosures hereof, except as may be required by intended specific limitations thereto appearing in any of the appended claims.

What I claim is:

1. In a tubular latch bolt unit, in combination, a tubular case including spaced opposite edge walls and a side wall connecting said edge walls at one side thereof, said case being open at the side thereof opposite said side wall, said opposite edge walls being formed with transversely aligned cut-outs therein opening through the free edges "thereof, respectively, to provide "inset seats, a

bearing plate member mounted on said seats in position extending across and between said edge walls within the case intermediate said sidewall and the opposite open side of said case, said bearing plate member being formed with a bore'tra'nsversely therethrough and being provided at one edge thereof transversely ofsaid case with an inwardly extended arcuate flange, a rollfback mounted in position against the inner "side of said bearing plate member, said roll-back having "an arcuate edge in slidable bearing engagement with said arcuate flange of said bearing plate member, said roll-back being adapted for rotation about the axis of said bearing plate member bore, and a closure cap attached to said case over and 010sing the open side thereof in position spaced from said roll-back when the latter is in operative mounted position on said bearing plate member.

2. In a tubular latch bolt unit, in combination, a case formed to provide a side wall, spaced opposite edge walls and an end wall closing one end of the case, the opposite end of the case and the side thereof opposite said side wall each being open, said opposite edge walls each being of reduced width along intermediate portions thereof to form elongated inset seating edges therealong, each of said edge walls being provided with a cut-out therein to provide an inset seat intermediate said end wall and the adjacent end of said reduced width portion of the edge wall, tongues on each of said edge walls projecting outwardly from the free edge thereof at locations thereon intermediate said end wall and said inset seat at one end of the case and at the opposite end thereof intermediate said open end and the adjacent end of the reduced width portion of said edge wall, a bearing plate member mounted on said inset seats in position extending transversely through said case between said edge walls and intermediate said side wall and the opposite side of said case, a cap member mounted in position seated on said elongated seating edges of said edge walls over and closing the open side of said case spaced from said bearing plate member, and said cap member being formed with seats formed in the edges thereof adapted to be engaged by said tongues, respectively, to maintain said cap in position on and closing said case.

3. In a latch bolt unit, in combination; a tubular case including spaced opposite edge walls each having a portion thereof cut-out inwardly through an edge of the wall to provide therein an inset edge disposed longitudinally of the wall intermediate the opposite side edges thereof to form an inset seat; said seat forming edges being aligned transversely of said case and ends of said edges being extended by undercuts in said walls, respectively, to form retaining slots into which said seats extend; and a substantially flat bearing plate member mounted on said seats and received in said retaining slots in position extending across said case between said opposite edge walls.

4. In a tubular latch bolt unit, in combination; a case providing a side wall, an end wall, and spaced opposite edge walls to form a case open at one side and at one end thereof; said opposite edge walls being provided with recesses forming inset seats therein, respectively, aligned transversely of said case intermediate the open side and said side wall of the case; a bearing plate member mounted on said transversely aligned seats in position extending transversely through the interior of said case between said opposite edge walls and spaced from said side wall and of said-platemembenfacingthe open sideof said case; said flange at the inner side thereof facing said plate -member bore -being .formed to provide an arcuate bearing surface having the axis of said 'bore as a center; a 'rollback rotatably mounted in 'bea-ring engagementagainst the side of said bearing plate *member facing the open side i of said case for rotation about the axis of said bore; the e'dge ofsaid rollback-adjacent said bearing plate member flangebeing; provided with an arcuate bearing surface -complementary to and in bearingengagement with the arcuate bearing surface of said flange; and a 3 plate-like closure cap attached to said case over and --closi-ng the open side thereof rsaid rollbaok and" said'closure cap being formed in assembled"positions-thereof to form a spacetherebetween within said case.

-5. In atubular latch bolt unit, in combination; a tubular case including spaced opposite side walls-end spaced opposite.- edge swalls, said case in closedatone endebyan endwalland being open at the opposite end; a bearing plate member mounted at oppositeaedge portions thereof on-said opposite iedgeiwalls, respectively, in position extendingntherebetween through said' case intermediate and spaced from said opposite side walls; a rollback rotatably mounted in position in bearing engagement against one side of said bearing plate member for rotation thereon about an axis transverse of the plane of said bearing plate member; a yoke member reciprocably mounted in said case between said roll-back and the adjacent side wall of said case; said yoke member at its opposite ends having laterally inwardly projected flanges in sliding bearing engagement at their outer ends at opposite sides, respectively, of said bearing plate member with the adjacent side wall of said case; said yoke member at the end thereof adjacent the open end of said case having an end wall formed with an opening therethrough adapted to receive therein a latch bolt; and an expansion spring loosely mounted in the space between said end wall of the case and said flange on the adjacent end of said yoke and being confined under compression between said end wall and such flange.

6. In a latch bolt unit, in combination, a tubular case formed with one side wall, one end wall. and opposite edge walls to form a case open at one side and at one end thereof, and a plate-like closure cap fitted over said open side to close said case; said opposite edge walls being provided with cut-out portions therein opening through the side edges thereof to form transversely aligned edges disposed longitudinally of said case providing seats spaced inwardly thereof from and intermediate said side wall and said closure cap; the adjacent ends of said edges of said cut-out portions being extended inwardly by undercuts in said edge walls, respectively, to provide retaining slots therein; a substantially flat bearing plate member having planar opposite side surfaces, said bearing plate member being engaged at its opposite ends on said edge wall seats in position extending across said case between said opposite edge walls and intermediate and spaced from said side wall and said closure cap; said bearing plate member being provided with portions thereof extending into said retaining slots to secure said bearing plate memberlinimountedposition said case; said bearing plate memberhaving aibore transversely therethrough; "and a rollback member mounted inposition at one;sideoflsaidbearing plate meniber in bearing engagement with the planar surface :thereof for rotation about-the axis of said bore in said :bearing-plate member. r :7. :Ina latch bolt unit, in combination; a tubular case including spaced opposite walls; said walls being formed to "provide" seats therein aligned transversely-of said case; abearing'plate .member-mounted on said seats in position extending transversely of said case through the interior thereof betweeri and intermediate the ,oppositeedges-of saidspaced walls; said-bearing .plate-membierzhaving "a boretherethroug'h and being formed across oneend thereof with a; guide flange provided at the-inner'side thereof facing said plate memberibore with an arcuate bearing surface generated aboutthe axis of said bore as aacenterisa rollback me nber'atone side of said bearing (plate member .mounted for rotation about: the axis of saidbore inbearing engagenent against theadjacent side of said bearing plate, member; i and-said rollback being "formed with an arcuate bearing-surface thereon in bearing engagement with the arcuate bearing surface ofsaid guide flange.

L8. In a .latch' bolt mechanism, in combination; a tubular case including spaced opposite walls; said walls being formed to provide seats therein aligned transversely of said case; a bearing plate member mounted on said seats in position extending through the interior of said case between and transversely of said spaced walls and having a centrally located bore transversely therethrough; said bearing plate member having one edge portion thereof formed to provide an arcuate flange extending laterally of said plate member from one side thereof spaced from and being generated about the aXis of said bore as a center; and a rollback member mounted for rotation at and in bearing engagement against the side of said bearing plate member from which said arcuate flange extends; and said rollback being mounted for rotation about the axis of said bore and the edge thereof adjacent said arcuate flange being formed for bearing engagement thereon.

9. In a tubular latch bolt unit, in combination; a. tubular case including a side wall and spaced opposite edge walls with the side of said case opposite said side walls being open; said opposite edge walls having cut-outs therein providing inset edges forming seats in said edge walls, respectively, aligned transversely of said case; a closure cap member attached to said case over and closing the open side thereof; a substantially flat bearing plate member mounted on said inset seats in said edge walls in position extending across and bridging said case therewithin between said edge walls intermediate but spaced from both said side wall and said closure cap member; said bearing plate member having a bore transversely therethrough and being formed to provide a substantially planar bearing surface at the side thereof facing and spaced from said closure cap member; and a rollback member mounted at the side of said bearing plate member facing said closure plate member for rotation about the axis of said bore through said bearing plate member in bearing engagement with said planar bearing surface thereof.

10. In a latch bolt mechanism, in combination; a tubular case including spaced opposite walls; a substantially flat bearing plate member mounted in position extending through the interior of said case between said spaced walls intermediate the opposite edges thereof; said bearing plate member having a bore transversely therethrough and having one edge thereof formed to provide an arcuate flange extending laterally of said plate member from one side thereof spaced from and being generated about the axis of said bore as a center; a substantially flat, plate-like rollback member mounted in position in said case for rotation at and in bearing engagement against the side of said bearing plate member from which said arcuate flange extends;

and said rollback member at the edge portion thereof adjacent said arcuate flange being formed to provide an arcuate surface for bearing engagement on said arcuate flange.

11. In a tubular latch bolt unit, in combination; a tubular case including spaced opposite side walls and spaced opposite edge walls; a substantially flat bearing plate member mounted at opposite edge portions thereof on said opposite edge walls, respectively, in position extending therebetween through said case intermediate and spaced from said opposite side walls; said bearing plate member having a bore transversely therethrough; a substantially flat rollback member rotatably mounted in position for bearing engagement against one side of said bearing plate member for rotation thereon about the axis of said bore in said bearing plate member and being spaced from the adjacent of said opposite side walls of said case; said rollback member having a bore therethrough for axial alignment with said bearing plate member bore; a yoke member reciprocably mounted in said case across and between said rollback and the adjacent side wall of said case adapted to retain said rollback against displacement laterally from position at said bearing plate member; and said yoke member being provided with an elongated slot therethrough opposite and aligned with said aligned rollback member and bearing plate member bores and at its opposite ends having lateral inwardly projecting flanges in sliding bearing engagement at their outer ends with the adjacent wall of said case at opposite sides, respectively, of said bearing plate member.

GOTTHARD HAGSTROM.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,390,756 'Voight Dec. 11, 1945 2,486,268 Erkkila Oct. 25, 1949