US2454754A - Door latch - Google Patents

Description

Nov. 23, 194s. F NETSCHERT 2,454,754

DOOR LATCH Filed Dec. 21, v1946 INVENToR. Hem/Z /Vfrsc// Patented Nov. 23, 1948 DOOR LATCH Franz Netschert, Glendale, Calif., assigner to Technical Glass Company, Los Angeles, Calif., a corporation of California Application December 21, 1946, Serial No. 717,644

2 Claims.

mounted in one escutcheon plate to be able to lock the latch. It is a further object of the invention to provide latch mechanism operable from either side of a door and fitted with a locking mechanism incorporated in the escutcheon plate on one side of the door, but arranged so that by proper manipulation of the handle on the opposite side of the door it may be unlatched.

It is a still further object of the invention to arrange the locking mechanism of a latch of the kind described so that the operation of the locking mechanism will be positive, eliminating backlash which may be detrimental to the functioning of the mechanism.

Still further objects and features of the invention will hereinafter appear from the following description taken in conjunction with the accompanying illustrative drawings in which is shown an embodiment of the invention at present deemed preferable by me.

In the drawings:

Fig. 1 is a Vertical section taken through the spindle, escutcheon plates, and locking mechanism mounted therein, of my invention;

Fig. 2 is a section on the line 2 2 of Fig. l;

Fig. 3 is an exploded View showing the component parts of the latch locking mechanism in their order of assembly;

Fig. 4 is a detailed View in side elevation of a locking piece; and

Fig. 5 is a cross section on the line 5 5 of Fig.

Fig. 6 is a longitudinal section through a modied form of latch member; and

Fig. 7 is a detail drawn to a larger scale of a cam member in the latch shown in Fig. 6.

In the drawings, the numeral Ill indicates the handle on the outside of a door, which is secured in a, socket member threadedly mounted on a spindle i4, which is of rectangular cross section. The spindle passes through a latch member generally indicated at I6, and is resiliently connected to an extension spindle indicated generally at I8. An inner handle or knob 2Il is threadedly secured to the extension spindle and knob being turned in either direction. The latch Y mechanism shown, by way of example, in Fig. 2, comprises a cylindrical housing 28 formed with removable cover to enable the mechanism to be placed in the housing, in Fig. 2, the housing cover is shown with the cover removed. The mechanism comprises a latch 30 formed as an extension of a, slide 32 having a downwardly turned flange 34 and an upwardly turned flange 36, the latter limiting forward movement of the latch through an opening in the front end of the housing. A fiat bar-38 is arranged to project across the interior of the housing, and a helical spring 40 is compressed between the flat bar and the upturned flange 36 to normally hold the latch in projected position. The slide may be retracted by a second slide 42 having an upwardly extending flange 44, and a second helical spring 45 arranged between the upwardly extending flange and the flat bar 33. A laterally projecting finger 43 extends from the slide 42 into engagement with the downwardly turned flange 34 of slide 32. rlhe rearward end of slide 42 is provided with an opening 50 embracing a cam member 52 through which the spindle I4 extends. 42 is provided with an upwardly extending flange 54 terminating in forwardly directed rounded surfaces engaged by flat surfaces of the semicircular cam 56 carried by the cam member 52. On rotating either door knob, the semi-circular cam will engage and force backwardly the retracting slide 42, which will in turn retract th latch slide 32.

Locking of the latch 3Q is effected by mechanism acting to prevent the rotation of the spindle I4 and extension spindle I8. The locking mechanism is shown in detail in Fig. 3 and comprises a stamped shell 58 fitting within the escutcheon plate 24. The stamped shell comprises recesses 6|! and E2 which receive a locking member, or lever, 64, the recess 62 also receiving a small leaf spring 66 serving to hold the locking member 64 inveither open or locked position. The locking member` extends through cutout portions 62a of the stamped shell and 24a. of the escutcheon plate 24.

A locking plate 63 fits into a central depression 'lll in the stamped shell and is furnished with a parallel sided opening 12 fitting on the extension spindle I8. The locking plate is provided with The rearward end of slide four recesses 14, arranged at right angles to one another, the side walls of the recesses being tapered slightly inwardly toward one another. A locking piece 'I6 is positioned against the locking plate 68, the shape of this locking piece being shown in detail in Figs. 4 and 5, from which it will be observed that the plate is furnished with a projecting arm I8 which is received in the recess 80 stamped in the shell 58, and with a downwardly turned iinger 82 received in recess 83 of the shell 58. The end of finger 82 is adapted to enter and wedge in any one of the recesses 14 when operated by the locking member 64. Both the locking piece 'I6 and locking member 64 are provided with a central recess clearing the extension spindle I8, but the recess in the locking member 64 is suiiciently large to permit of a rocking movement of the member 64 about its lower end.

The operation of the locking mechanism is as follows: If the member 64 is placed by pushing knob 84 in position at one end of its slot 24a, such that finger 82 is moved clear of notches 14, spindle I4 may be freely turned. If member 64 is rocked to the opposite end of its travel while knob 20 is rotated slightly, nger 82 will snap into one of notches 'I4 and by reason of the tapered walls thereof will firmly hold locking plate 68 against rotation and thus will hold extension spindle I8 against rotation. The spindle, while being resiliently connected to spindle I4 is arranged in normal position, to turn with spindle I4 by virtue of the construction now to be described.

.Extension spindle I8 is of somewhat greater cross section than spindle I4 and is resiliently held for turning therewith by means of a rectangular recess in the enlarged end 86 of spindle I8 which recess iits snugly on the rectangular spindle I4.

The recessed head of the enlarged end 86 is normally held in engagement with spindle I4 by a spring 88 engaging between the head 80 of a machine screw 96 passed through an axial smooth walled bore 92 in the end of stem I4. The machine screw may be retainedin adjusted position in the bore in spindle I4 by dimpling the end of spindle I4 with a center punch as indicated at 94 to jam the machine screw in the threaded bore. The construction described, enables the spindle to be easily and quickly assembled and the load on the spring to be adjusted so that a pull of desired strength is required to bring the end of spindle I4 free of spindle I8, and provides the feature that should the locked door require to be opened from the outside, for instance, as may happen in the case of a young child who unknowingly locks itself into the room while playing with the door handle, or an invalid subject to fainting spells who has locked the door but is unable to unlock it because of such a spell, a nurse or other party can open the door from the outside by pulling strongly on the outside door knob and then turning the knob in either direction.

In Fig. 6, I show a form of latch in which a single spring 88 is provided normally holding the latch Ill!! in projected position, but permitting the latch to be pushed into the door by the door jamb when closing the door without turning the handle.

The latch is assembled in a case not visible in the figure to which an abutment for the spring is secured. The construction of the latch per se is fully described in my co-pending application,

Serial No. 672,148, led on May 5, 1946, to which reference may be had, but the present invention is not concerned with the particular type of latch provided, but with locking means therefor, of the kind described, and the adaptability of the parts to latches of various types, of which two are given, by way of example.

The latch shown in Fig. 6 is withdrawn by means of a double cam and adaptor piece as described in the patent application referred to, necessitating the provision of three formed pieces. According to this invention, the latch may be operated by a cam member (shown in Figure 7) formed from a single stamped blank, providing spaced cam parts I04a, |0412, connected by a web portion. Locating discs I04d, I04e iitting in recessed seats in the latch housing through which the spindle passes are connected to and spaced from cam parts I04a and |0417 respectively. Alined square holes are formed in each locating disc and in the web by which the cam member may be mounted on the spindle to operate a latch of the form shown in Fig. 6.

It will be evident that I have provided improved locking and operating means for door latches of the kind described and have described and illustrated preferred embodiments of the invention, but it is to be understood that various changes and modiiications may be made by those skilled in the art, without departing from the scope of the claims appended.

I claim:

l. Latch mechanism for a door including: an outside handle; latching means for said door; a spindle on which said outside door knob is secured and rotatable to retract said latch and extending on the opposite side of the door; an inside door knob secured to said spindle; locking means operable from inside the door to prevent rotation of said spindle; resilient means normally operative to hold said spindle in position to be held by said locking means when operated but enabling said spindle to be moved axially by an axial pull on said outer handle to be released from said locking means while remaining in engagement with said latching means to enable the door to be opened from the outside notwithstanding that the locking means remain in locking position.

2. Latch mechanism as set forth in claim 1, and in which said spindle comprises an outer portion to which the outer handle is secured and which operates to withdraw the latch mechanism to open the door; an inner portion to which the inner handle is secured; clutch means adapted to con nect the inner and outer spindle sections; and resilient means normally holding said clutch in position to ensure unitary rotatory movement of the inner and outer portions of the spindle.

FRANZ NETSCHERT.

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

UNITED STATES PATENTS Number Name Date 666,800 Chase Jan. 29, 190i FOREIGN PATENTS Number Country Date 171,565 Great Britain NOV. 24, 1921

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