US1340804A - Pin-tumbler lock - Google Patents

Description

F. E. THOMPSON- PIN TUMBLE nPPucmou min I? LOCK. MN. 30. 1920.

Patented May 18, 1.920.

UNITED STATES PATENT OFFICE.

FRANK E. THOMPSON, OF STAMFORD, CONNECTICUT, ASSIGNOR TO THE YALE & TOWNE MANUFACTURING COMPANY, OF STAMFORD, CONNECTICUT.

PIN-TUMBLEB LOCK.

Specification of Letters Patent.

Patented. May 18, 1920.

Application flied January 30, 1920. Serial No. 355,034.

To all whom it may com/cm:

Be it known that I, FRANK E. THOMPSON, a citizen of the United States, and a resident of Stamford, in the county o-fFairfield and State of Connecticut,'have invented certain new and useful Improvements in Pin-Tumbler Locks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it a pertains to make and use the same.

y invention relates to an improvement in pin tumbler locks.

in pin tumbler looks, as ordinarily constructed, when a key is being inserted in the plug, the beveled surfaces on the end of the key and on each of the bittings or angles raise the pins, each in its respective pin hole in the plug and also force the lower end of the pin back against the rear face of the pin hole, and as the pin is carried up by the advancing key, it causes a wearing action on both the pin and its pin hole. As the key is withdrawn from the plug, this action is reversed, bringing the wear upon the front surface of the pin hole.

This action is not so serious when a key with a comparatively thin cross section is used, but in many instances it is desirable to so slot the key plug that keys differing in cross section may enter the lock and operate the pin tumblers. This however necessitates the employment of a wide slot which is nearly as wide as the diameter of the pin tumblers, thus necessarily leaving the latter with but a limited support at their front and rear surface in the plug, so that when the key is inserted and withdrawn as above explained, wear between the tumblers and the supporting surface in the plug for the latter soon impairs the efliciency of the lock.

The object of the present invention is therefore to provide means for taking the strain and. consequent wear from the tumblers and the walls of the holes in the plug in which they are mounted, and it consists in the parts and combination of parts and in the details of construction as will be more fully explained and pointed out in the claims.

In the accompanylng drawings; Figure 1 is a view of a lock partly in section and partly in elevation embodying my invention; Fig. 2 is an enlarged View of a portion of the key plug, the tumblers and a part of the key; Fig. 3 is a view in section on the line {LL-58 of Fig. 2, and Fig. 4 is a view in horizontal section through one of the tumlilers and showing the key slot in the plug and the restricted l'ienring for the tumblers.

5 represents the cylinder of a pin tumbler lock and 6 is the plug mounted to turn in the latter in the usual and well known manner. The cylinder is provided with holes or recesses arranged to aline with similar holes in the plug for the reception of the pin tumblers T which are of the well known construction and are operated. by a key 8 in the usual and well known manner. The key slot in the plug 6 is comparatively wide to receive keys differing in cross section, thus producing a slot which is nearly as wide as the diameter of the pin tumblers, so that the portions of the tumblers projecting into the key slot have but a limited bearing or support at diametrically opposite points as shown at 9 in Fig. 1.

the key is entered into and withdrawn from the plug 6, the tumblers are forced first back and then forward by the contact of the lower ends of the tumblers with the angles or the bittings on the key 8, and this action comliiined with the vertical movements of the tumblers soon wear the plug and tumblers and produce a looseness between the parts which interferes with the operation of the lock and soon renders it worthless.

To overcome this trouble I provide each tumbler with a guiding pin 10 projecting at opposite sides and located adjacent its lower end as shown. These guiding pins are located at right angles to the direction of the in and out movement of the key, and rest and move in grooves 11 formed in the plug (3, the lower ends of the said grooves in some instances forming stops for limiting the downward movements of the tumblers and for holding them in proper position with their lower ends within the key slot so as .to be engaged and successively raised as the key is passed into the slot. If desired the tumblers instead of being supported by the pins resting on the bottoms of the grooves may drop so as to rest in their normal manner at the bottoms of the tumbler holes in the plug. These pins bearing against the walls of the grooves take all the wear from the tumblers and the walls surrounding the 'latter and absolutely prevent any movement of the tumblers that could cause them to bind in the holes or recesses.

As; the key is entered in the key slot the tumblers are successively raised, ride over the angle or bittings of the key and drop into their proper seats on the latter, and when the key is removed they drop down so that their lower ends are in the key slot and in position to tbe engaged by the key and are so held by the pins ll) resting on the bottom walla of the 'rooves 11 or at the bottoms of the tumbler holes in the plug.

Having fully described my invention What I claim as new and desire to secure by Letters-Patent, is

1. In a pin tumbler lock, the combination ol' :1 cylinder, a plug having a key slot, a pin tumbler for looking the plug against rotation in the cylinder and means projecting from the tumbler and resting in grooves in the plug,- for preventing the tumbler From binding.

2. ln :1 pin tumbler lock, the combination of a l-ylinder, a plug having a key slot, :1

pin tumbler and pins projecting from the tumbler at opposite sides of the latter and resting and moving in grooves in the plug. il. in a pin tumbler lock, the eombination of a cylinder, a plug having a key slot, a pin tumbler. and pins projecting from the tumbler at right angles to the direction oi. the length ol' the key slot and resting and moving in grooves formed in the plug.

ln a pin tumbler lorlg the combination of a cylinder, a plug; having a key slot, a pin tumbler, pine projecting from the latter at opposite sides and in a direction to take the strain imparted to the tumbler by the in and out movement of the key, and guides for the said pins the said guides exteni'ling down into the key slot.

ln testimony whereof, l have signed this speeili -ation in the presence of two subscriblltJf \vitneeseq.

FRANK W itnessen Hiuuins A. lmnnY. JUIJUH A. Wns'r.

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