US216904A - Improvement in latches - Google Patents

Description

O. H. .ISMITH. Latch.

m. 216,904. Patentedlun 24, 1879 B FIG-I.

FMS/2.

INVENTOR NFETEHS. PHOTD-LITMOGRAPHgH. WASHINGTON, D c.

TINI'TED' STATES PATENT QnnmE;

CHARLES H. SMITH, OF NEW HAVEN, ASSIGNOR TO THE RUSSELL & ERWIN MANUFACTURING COMPANY, 'OF NEW BRITAIN, CONNECTICUT.

IMPROVEMENT IN LA TCHE'S.

Specification forming part of Letters Patent No. 216,904., dated June 24, 1879; application filed April '28, 1879.

To all whom it may concern:

Be it known that I, CHARLES H. SMIrmof the city and county of New Haven and State of Connecticut, have invented a certain new and useful Improvement in Door-Latches; and I do hereby declare that the following specification, taken in connection with the accompanying drawings, forming a part of the same, is a full, clear, and exact description thereof. V

The improved latch hereinafter described belongs to that class in which, upon the complete closing of the door, the latch-bolt previously held back within the case is permitted to be projected into the mortise in the doorjamb for the purpose of securely holding the door.

In my invention a square insteadof a bev el-faced IEI-tCll bOIh is employed, and which is at all times housed within the latch-case unless acam-faced lever, which projects beyond bined with the latch-bolt, as hereinafter eX-' pla'ined, is pressed inward, in which case, if the door be open, the bolt will be moved outward as the lever is moved inward, but if the door be closing and the face of the latch be.

abutting against any part of the door-jamb or usual striker-plate, the latch will beheld within the case until the door isfully closed, notwithstanding that the operativecam-faced lever is moving inward. The movement of the said lever, however, inward winds up a spring, which reacts when the bolt is in line with the mortise in the jainb, and projects the bolt forward to hold the door fast.

The construction shown in the drawings exhibits several advantages. In the first place, the cam-faced lever projecting beyond the faceplate presents a slight frictional resistance to the door in closing. Again, inasmuch as this lever operates to cause the bolt to be projected. forward instead of operating to force a latch inward, as in the case of ordinary lever-latches, a square-headed latch-bolt can be employed, which has the advantage of great strength; but especially is this arrangement important, for the reason that when the bolt is shot forward afterthe door is closed it is impossible.

to insert a knife blade between the striker plate and the edge of the door and push back the bolt, whereas in all leverlatches operat' ing to push the latch inward a bevel-faced" r In my improved latch thecam-lever is held inward by contact with the striker at all times when the door is closed, and pressure against it has no tendency to move the latch-bolt backward.

Referring to the drawings, Figure 1 represents a view of the latch with the bolt in its rearward position, thecap-plate beingremoved. Fig. 2 shows the same with the bolt projected.

Fig. 3 represents a'seetion of the faceplate-on line as .40, showing the projecting operating-lever hinged thereto, and Fig. at represents a modification of certain parts of the latch. the plane of the face-plate, and whichis co1n-- As shown in each of the figures, A represents the case of the latch; B, the face-plate of the same; 0, the hub, and D the lever worked by the knob-spindle towithdraw the squarefaced bolt E when the door is closed. Hinged to the face-plate B is a vibrating cam-faced lever, F, which has a salient face projecting beyond the face-plate for .the purpose of im pinging against the striker-plate when the door is closing. Engaging the rear face of this lever, as shown in Figs. 1, 2, and 3,1s the long arm of a bell-crank lever, Gr,p1voted to the case, and provided with a flat spring, H, which keeps the levers G and F in contact.

The short arm of this lever G is furnished with one or more teeth, which mesh with the teeth of anotherbell-crank lever, K, also pivoted to the case A. Upon the pivot K of the lever K is arranged a coil-spring, L, the short arm, 1, of which engages a pin, k, on the short arm of the lever K, the long arm, Z, of said spring engaging a lug, c, on the latch-bolt. The long arm of the lever K engages a lug, e, on the bolt E, and by the force of the springs H and L tends to keep the said bolt in its rearward position.

As shown in Fig. 1,. when the bolt E is housed in the latch,:which is always thecase whenthe door is open, the lever D is not in contact with it, and can in no way exert an operating force upon it. Under these conditions, if the cam-faced vibrating lever F should be worked, the spring L would act only as a lever, and move the bolt E outward and inward simultaneously with but in a direction opposite to that of the movement of the vibrating lever F, the spring H returning the parts to their respective positions shown in said figure. When the door closes, however, the spring L takes on its proper function, and no longer acts as a lever, but as a spring, as will now appear.

During the movement of the door to a closed position the projecting vibrating lever F comes in contact with the striker-plate, and is turned backward upon its pivot. This movement operates the'levers G and K, and tends to advance the bolt by the lever action of L. The outward movement of the bolt, however, is prevented until the mortise in the strikerplate is in line with the head of the bolt, which does not occur until the door is fully closed and the lever F moved to its farthest rearward position. The bolt, therefore, being thus pre vented from advancing by the striker-plate during the backward movement of the lever F, the long arm of L remains in position, while its short arm, Z, moves with the lever K, as

shown by broken lines at Fig. 1. This winds up and increases the force of the spring L, so that when the mortise and bolt-head become aligned it discharges its spring function, and projects the bolt into the mortise by a movement of its arm Z, the parts assuming the position shown by full lines at Fig. 2.

The forward movement of the bolt brings its tail into contact with the lever D, in which position the bolt is retained by the spring L, ready to be withdrawn by the lever D when operated by the knob-spindle for the purpose ofopening the door. When this lever is moved and the bolt retracted the spring L would resume its lever function were it not that the vibrating lever F is prevented from advancing, because of its contact with the strikerplate. The levers G and K, therefore, remain stationary, and only the long arm, 7/, of the spring L is moved by the bolt. This increases .the force of the spring by winding it up, as

shown by broken lines in Fig. 2, so that when the bolt'has been retreated into its case, and the lever Fis allowed to advance by the opening of the door, the lever will be projected into its original position beyond the latch-face by the joint action of the springs L and H.

Although, as hereinbefore described, a bellcrank lever, D, is used to retract the bolt for the purpose of opening the door, and levers G K are employed to increase the tension of the spring L, yet a common yoke may be substituted for the lever D, and a single lever for the levers G K. Such a modification is shown at Fig. 4, where D represents the yoke in engagement with its hub and overlying the tail of the bolt, a spring, cl, operating to keep the parts in the position shown. vibrating lever F is engaged by an arm, 9, which is pivoted to a lever, G, and controlled by the spring H. The lever G is pivoted to the latch-case, and its end 9 is in contact with the bolt. The spring L is placed upon the pivot of the lever G, and its ends respectively engage the end g of the lever G and the head of the bolt E. Under this arrangement the spring L performs the same functions as the spring L, the lever G the same as the levers G and K, the spring H the same as the spring H, and the yoke D the same as the lever D. The movements of the bolt E and vibrating lever F, therefore, are the same as before specified.

From the foregoing description it will be seen that when the door is open the latch-bolt will be housed in its case so long as the lever F projects to its full extent beyond the faceplate B 5 that should the leverF be moved when the door is in this position, the bolt will be operated simultaneously with but opposite in direction to the lever by the lever function of the spring L or L, and that when the lever F ceases to be manipulated the spring H or H will house the bolt and project the lever into the proper position for the closing of the door. It will also be seen that when the door is closing or opening the movements of the lever F and bolt E are not simultaneous, but that the complete movement of one is followed by the complete movement of the other, the spring L or L performing its true spring function to advance the bolt or project the lever F, as the case may be.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s-- 1. The combination of a vibrating lever piv oted to the latch-case and projecting beyond the face-plate, a sliding bolt held back by spring-pressure within the latch-case, and intermediate operative mechanism, substantially as described, whereby the bolt will, by leverconnections, be moved outward as the vibrat ing pivoted lever is moved inward unless the bolt is forcibly held back, but if so held the movement inward of the said lever will wiim up a spring in readiness to project the bolt so soon as the obstacle is removed, as set forth.

2. The combination of a vibrating cam-lever pivoted to the latch-case and projecting beyond the face-plate, a lever or a connected train of levers within the latch case and oper ated by the cam-lever, a sliding bolt held back within the latch-case, and a spring which is wound up by the movement of the cam-lever inward, substantially as and for the purpose specified.

3. The combination ofa sliding latch-bolt, a lever or a connected train of levers operat ing under spring-pressure to slide the bolt into and retain it within the latch-case, and a flexible spring-lever, L, arranged to throw the The projecting bolt forward when the bolt is relieved of the pressure which tends to hold it back, substantially as described.

4. The combination, as substantially before set forth, of i the sliding bolt, the hub and its arms worked by the knob-spindle, suitable mechanism connecting the bolt with the hub, mechanism, substantially as described, for retracting the bolt independently of the knob spindle and its connections when the vibrating cam-lever is not pressed inward, and mechanism, substantially as described, for projecting the bolt when the door is fully closed.

"lever and its connections for working the vi.-

brating lever, substantially as described.

' CHARLES H. SMITH.

' Witnesses:

THEo. E. SMITH, H. E. RUssELL, Jr.

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