US2644706A - Latch - Google Patents

Description

July 7, 1953 F- IJ. Mccolsmlm.

LATCH Filed May 18 Fis. 2

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Patented July 7, 1953 LATCH Frank J. McConnell, New Britain, Conn., assignor to The American Hardware Corporation, New Britain, Conn., a corporation of Connecticut Application May 18, 1950, Serial No. 162,735

Claims.

My invention relates to a door latch and is an improvement over the structure disclosed in my U. S. Patent 2,614,876, issued October 21, 1952.

It is an object of my invention to provide an improved device of the character indicated.

It is another object to provide an improved cylindrical latching device insertable as a unit within a single bore in the edge of a door.

It is a specific object to provide animproved auxiliary latch construction in a device of the character indicated.

It is another object to provide improved dogging means for a latch bolt.

It is in general an object to meet the above objects with a structure that is relatively simple, reliable, trouble-free, and, to the greatest extent possible, of low-cost construction.

Other objects vand various further features of novelty and invention will be pointed out or will occur to those skilled in the artfrom a reading of the following specification in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, preferred forms of the invention:

Fig. l is a side elevation of a latch 'assembly incorporating features of the invention;

Fig. 2 is a front end View of the assembly of Fig. 1, showing the latch bolt and latch front;

Fig. 3 is an enlarged longitudinal sectional view taken substantially in the plane 3"-3 of Fig. 1;

Fig. 4 is a sectional View taken at right angles to the section of Fig. 3 and generally in the plane 4-4 of Fig. 3;

Fig. 5 is a sectional view similar to Fig. 3 but showing the parts in a diierent relationship;

Fig. 6 is an enlarged sectional view in the plane 5- 5 of Fig. 3;

Fig. 7 is a fragmentary longitudinal elevation of a partially assembled slightly-modified construction; and

Fig. 8 is a sectional view more or less in the plane 8 8 of Fig. 7.

Briefly stated, my invention contemplates an improved latch assembly of generally cylindrical external configuration, for. insertion Vin a cylindrical bore in the edge of a door. The construction may involve substantially only sheet-metal parts, and my improvement resides principally in the mechanism for effecting clogging function by way of an auxiliary bolt slidable alongside, but

relatively to, a main bolt. The retractor means for the main bolt may be essentially the same as that described in the said copending patent application,q and the retractor may, therefore, include a base plate for guiding the main bolt and the auxiliary bolt and for supporting a latch dog. The dog may be a transversely slidable plate appropriately supported and guided by the car-iv riage, and engageable with the tail of the main bolt in one position and free of the main bolt in another position. Spring means may urge the dog plate toY one of said positions, and cam means cooperating between the auxiliary bolt and the dog plate may be effective to move the dog plate to the other position upon relative longitudinal movement of the auxiliary bolt and of the carriage.

Referring to the drawings, my invention is shown in 'applicationl to a vcylindrical or tubularl latch suitable for insertion in a bore drilled in the edge of a door. The latch assembly may include a generally tubular case which may comprise split semi-cylindrical halves Ill-II. At the front, a cup or cap or sleeve I2 may hold the halves I-I I together and may support a latch front I3. A snap lug I4 on one of the members Ill-I I may engage an opening in the sideof the cap I2 to secure the front to theY casing. At

the rear end, another cap or cup member I5 may hold the casing members IU-I I together and may be secured in position, as by engagement of .a'

bayonet slot I6 with a nibl I'I on the back end Vof one of members IEE-I i ;v in the form shownjthe bayonet slot is provided in duplicate so that engagement may be had with nibs' II-IB on bothl case parts I-I I.

The principal moving parts of the latch assembly may include a main bolt 20 and an auxiliary bolt 2| slidable longitudinally relatively to each other and urged to outwardly projected positions,

as by means of compression springs 22-23 re-k spectively. The compression springs 22-23 may be supported on cylindrical tail sections 24-25 forming parts of the main and auxiliary bolts 2li-2|, respectively, as described in the above@ mentioned copending patent application. `The auxiliary bolt 2l may be in partV guided by la groove 26 in the main bolt, and an offset part or end 21 of the auxiliary latch tail 25 may serve as a limiting abutment vor shoulder to engage the' main bolt 20 to assure no further projection of the auxiliary bolt 2l relatively to the main bolt 20 beyond that shown for example in Fig. 3.

The retraction means for the bolts may include a rollback driving a retractor orcarriage. The rollback may comprise twin opposed stamped sheet-metal cups 29-38, each of which may be formed with correspondingvteeth 3l to define a sector gear for actuating engagement with the The .bases ofthe cups 29-30 may define journals supported in bearings, as at 32, pressed inwardly and out of the material of the latch-casing members ID-ll. The bottoms 33 of the rollback cups 29-30 may be pierced with appropriate openings for engagement with a latch spindle (not shown) forming part of a knob or other actuating assembly, which may suitably be a mechanism as more fully described in the copending patent application of Frank J. Mc- Connell and Irving J. Fletcher Serial No. 104,422, led July 13, 1949.

As indicated generally above, the retractor carriage may include spaced arms or sides 34-35. These sides 34-35 may be bent up out of a single strip of sheet material and joined.

to each other at a bridge 36 at the rear of the assembly and behind the rollback mechanism. The bridge 35 may serve as a means to receive the constant urging of a compression spring 31 held against the bridge 35 by means of the rear cap I and thus constantly serving to urge the carriageY to the forward position shown. The side members 34-35 of the carriage may be formed with gear teeth or lugs to be engaged by the sector teeth 3l of the rollback means; however, in the form shown, rack teeth may be effectively provided by means of openings or windows 38 punched at regular intervals on both sides 34-35 of the carriage. It will thus be clear that Vcarriage retraction may be achieved upon rollback actuation in either direction and, depending upon what the direction of rollback actuation, one or the other of the side members 34-35 of the latch carriagel will be forcibly retracted.

'The forward end of the latch carriage may be defined by a base member or plate 45 secured in .the projecting side members 34 and provided withxguide openings 4i-42 for sliding support of vthe main and auxiliary latch tails 24-25. The rear end of the bolt tail 24 may include an enlargement or abutment to limit forward or projecting displacement of the main bolt 23 when intercepted by the base plate 46, and to simplify the construction, this enlarged end or abutment on the main-bolt tail 24 is a collar 43 fitting over a reduced end section 44 of the bolt tail' 24 and secured thereto, as by a pressed t or as by swaging or peening the end 44 to the collar -43 as at 45. Y

vIn accordance with a feature of the invention, I provide an improved means for introducing a dogging function in the described assembly. This function may be achieved by means of a single dog plate or slide 4B slidable over the back face of the plate 46 which forms the front end of the carriage. The dog plate 45 may have openings 41-43 corresponding to the openings 414-42 in the base plate 4t, and a dog slot may be provided transversely of both bolts or bolt tails 24-425 and to be slidably guided in a transverse plane between the plate 40 on the one hand and .a plurality of opposed inwardly bent lugs 50y (Fig. 4) on the side members 34-35 of the carriage.l

It Vwill be appreciated that the dog-plate member 46 mayV move between essentially two positions relatively to the bolt tails 24-25. In one of these positions (see Fig. 3), the opening 41 may be free of the main body of the main-bolt tail 24 so that, upon depression of the main bolt 20, as upon engagement with a strike, the bolt tail 24 may slidably enter the opening 4l, and no actuation or rearward movement of the carriage or of the rollback means 29-30 need be the dog plate 46.

Ybe appreciated that the dog plate may be movable to its other extreme position, for the milled `flat or notch 49 in the main-bolt collar 43 will also be inalignment with the dog plate 46.

In accordance with a feature of the invention, I provide a resilient means for urging the dog plate to one of its extreme positions, and c am means cooperating between the dog plate 46 and the auxiliary bolt 2l upon relative longitudinal movement thereof for moving or for making possible a movement of the dog plate 45 between its extreme positions. In the form shown, the

1 resilient means is constantly stressed to urge the plate 46 into the clogging position shown in Fig. 5. spring 52 mounted on a stud 53 carried by the base plate 4B of the retractor carriage. The

stud may include a transverse slot 53 milled across its inner face, and one end of the coil spring may be received in the slot 54 and held therein, as by peeningat 55. The other end 56 of the coil spring 52 may be hooked to a small lug 51 bent up and out of the material of the dog plate 4E, so as to provide a constant downward urging force in the sense of Figs. 3, 5, and 6. II'he cam means forl shifting the dog plate 46 to the other position may include a gentle cam. l slope 58 providing a transition from the recess 5I to the full cylindrical section of the auxiliary bolt tail 25, and it' will berappreciated that upon a relative longitudinal displacement of the auxiliary latch bolt with respect to the latch carriage, as upon a spindle actuation of a rollback means `2 9-30, the main bolt 20 may be retracted; duringY the retraction, the cam surface 58 may be' effective. Y:to withdrawthe dog ,plate .46 `fromdogginen 'engagementfwith the main bolt '26 'a't`49` In Figs. 7 and 8,"1 show a modified construction wherein alternative means are employed for defining the guide means for the dog plate 46. In this arrangement the dog plate 46 again rests on one side on the base plate member 4i), and,

in place of the lugs 5U of the previouslydescribe'd form, the guide means of Figs. 7 and 8 comprises merely straps `ll--fil which maybe generally U-shaped and punched out of the material of the spaced arms "3W-35v of the retractorcarriage.

. It will p clear that with the described modified structure there/may be minimum consumption of stock in fabricating the retractor carriagefand function. :My mechanism'contemplates the usev of relatively inexpensive sheet-metal'fabrication to the fullest extent, and I have found the operation of my construction to be definitely superior and to be characterized by long life. 1

While Ihave described my invention in detail forthe preferred forms shown, it will be under# stoodthat modifications may be made within the The vresilient means may comprise a coil scope of the invention as defined in the appended claims.

I claim:

1. In a latchng device, said device comprising a main bolt and an auxiliary bolt longitudinally slidable relatively to each other, a retractor carriage with respect to which both said bolts may be longitudinally slidable, said carriage including a base extending transversely of said bolts and including means for slidably guiding `said bolts, rst abutment means on said main bolt for limiting outward displacement of said main bolt relatively to said carriage, means resiliently urging said main bolt to an outwardly projected position, a dog plate separate from and independently slidable over the surface of said base and guided by said carriage for limited transverse movement relatively to said bolts, second Vabutment means on said dog plate and engageable with said first abutment means in a rst position of said dog plate and when said main bolt is in the extended position relatively to said carriage, said iirst and said second abutment means being disengaged from each other ina second position of said dog plate, whereby in said first position of said dog plate said main bolt and said carriage may be barred from relative longitudinal movement, while in said second position of said dog plate said main bolt and said carriage may be free for relative longitudinal movement, spring means urging said Idog plate to one of said positions, and cam means acting against said spring means and cooperating between said auxiliary bolt and said dog plate for controlling the movement of said dog plate from one of said positions to the other of said positions upon a relative longitudinal displacement of said auxiliary bolt and of said carriage.

2. A device according to claim 1, in which said sidemembers of said carriage are formed with said carriage so as to form oppositely facing in-` wardly bent guide means spacedv longitudinally from said base to deiine a guide path for said dog plate.

5. A device according to claim 1, said main bolt having a transverse notch therein near the rear end thereof, said rst abutment means including a transverse wall defining a part of said notch.

' VFRANK J. MCCONNELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,290,727 Best July 21, 1942 2,290,728 Best July 21, 1942 2,497,750 Wardwell Feb. 14, 1950

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