US2105659A - Lock - Google Patents

Description

Jan. 18, 1938. E N. JACOBI 2,105,659

LOCK

Filed Nov. 6, 1936 5 Edward N Jambz Patented Jan. 18, i938 cams STATES PA ENT OFFICE LOCK Edward N. Jacobi, Milwaukee, Wis, assignor to Briggs & Stratton Corporation, Milwaukee, Wis.,'a corporation of Delaware Application November s, 1936, Serial No. 109,417

3 Claims. (Cl. -364) This invention relates to improvements in tumbler locks andrefers particularly to pin type tumbler locks in which therotatable cylinder is secured against rotation by spring pressed tumblers moving from the easing into the cylinder to be lifted to inoperative position by key operable drivers.

In the manufacture of pin type tumbler locks, great pains-have been taken to limit the end playof the rotary cylinder to about two thousandths of an inch. If the cylinder is permitted lengthwise motion in excess of this amount, the.

resulting misalignment between the radial bores in the cylinder and in the casing'while the key is in place would prevent the free and unobstruct inch in each of three 'or four dimensions. This to allow for such misalignment is not permissible as the accuracy of the lock would then suiler greatly. 7

Consequently, manufacturers of pin type tumbler locks in the past have resorted to expensive manufacturing operations, such as keeping the casings and cylinders in matched sets after line reaming the tumbler chambers in both parts Where the cylinder and casing of the lock are die-cast, the problem becomes particularly grave for if it would be necessary to match and ream these parts in sets, the cost of manufacture would become prohibitive.

With these objections to past and existing pin tumbler locks in mind, it is an object of this invention to provide means whereby the entrance of the tumbler drivers into the casing tumbler chambersisatalitimesfreeandunobstructed even though the cylinder is permitted a normal 'range of lengthwise shifting in the casing bore.

- With the above and other objects in view which will appear as the description proceeds,

this invention resides in the novel construction, combination and arrangement of parts substan 'tially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the-claims.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a longitudinal sectional view through a pin type tumbler lock embodying this invention;

Figure 2 is a cross sectional viewthrough Fig ure 1 on the plane of the line 22; and

Figure 3 is a plan view of the lock casing per se. Referring now particularly to the accompanying drawing in which like numerals indicate like parts throughout the severalviews, the numeral 5 designates the casing of a conventional pin type tumbler lock which may be mounted in a housing.

or other support 6 and which has a longitudinal bore 1 to receive a rotatable'lock cylinder 8.

The cylinder 8 is inserted into the bore 1 from its inner end and has an enlarged flange 9 received in a counterbore ill at the inner end of the casing. Mounted on this flange 9 is an eccentric driving lug ll through which rotation of the cylinder is imparted to the mechanism controlled.

The cylinder is secured against endwise displacement in the bore by a retaining member l2 embedded in a transverse slot in the casing with its inner edge portion projecting into an annular groove 13 in the adjacent part of the cylinder. In this manner, the cylinder is secured against endwise displacement, but with normal operating clearances and without resorting to special means to restrict the possible end play of the cylinder to a minimum, it may shift endwise as much as six thousandths of an inch.

As is customary in the conventional pin tumbler lock, the cylinder has a plurality of radial bores or tumbler chambers 14 extending from the surface of the cylinder into a longitudinal keyway' I 5. Slidably disposed in these bores or chambers permitted by the drivers I6. The outer ends 01 the tumbler chambers II are closed by a plate 2| extending lengthwise of the casing and secured in place by swedging the metal of the casing over the edges of the plate, as shown in Figure 2.

As pointed out hereinbefore, under normal conditions, there is a possible misalignment between the tumbler chambers II and l I sufllcient to cause the ends of the tumbler drivers to engage the shoulders formed by the wall of the bore 1 adjacent the mouths of the tumbler chambers, and this seriously interferes with the withdrawalloi the key as the drivers must be free to enter the tumbler drivers into the tumbler chambers ll is assured throughout the full range of possible lengthwise shifting of the cylinder in its bore without in anywise detracting from the accuracy of the lock. 7 What I claim as my invention is:

1. In a tumbler lock, a bored casing, a rotatable cylinder mounted in the bore, said casing and cylinder having radial bores adapted to be aligned,

pin type tumblers and drivers respectively in said radial bores, and the radial bores in the casing being substantially oval with their major dimension lengthwise oi the lock so as to assure free entrance of the tumbler drivers into said radial bores in the casing regardless of normal endwise shifting of the cylinder in the casing, while retaining a close fit between the tumbler drivers and said radial bores in the casing to guard against any possible rotation oi the cylinder except when the junctures of the tumblers and their drivers are in line with the line of parting between the cylinder and easing bore.

2. In a pin tumbler look, a bored casing, a cylinder rotatable in the casing bore, means for holding the cylinder against endwise shifting within normal limits as determined by normal manufacturing practice, said casing and cylinder having radial bores adapted to be aligned, pin tumblers in the radial bores of the casing, key operable drivers in the radial bores of the cylinder projectible into the radial bores of the casing as the key is inserted and withdrawn, and said radial bores in the casing being of oval shape with the major diameter parallel to the axis of the lock to preclude the ends of the drivers striking the edges of the radial bores in the casing upon misalignment of the cylinder and casing radial bores due to normal lengthwise shifting of the cylinder in the casing bore, while retaining a close fit between the tumbler drivers and said radial bores in the casing to guard against any possible rotation of the cylinder except when the junctures of the tumblers and their drivers are in line with the line of parting between the cylinder and easing bore.

3. In a pin tumbler lock having a bored casing and a lock cylinder rotatable in the casing bore, the cylinder and casing having radial bores adapted to be aligned in one position of rotation of the cylinder, spring pressed tumblers in the radial bores of the casing, key operable tumbler drivers in the radial bores of the cylinder projectible into the bores of the casing upon insertion and removal of a key, means for holding the cylinder against lengthwise displacement in the bore, said means allowing normal clearance between .the parts which entails possible lengthwise shifting of the cylinder in the bore a few thousandths of an inch back and forth which motion is sumcient to objectionably misalign the radial bores in the cylinder and casing, and said radial bores in the casing being oval-shaped with their major diameters parallel to the axis of the lock to com-' pensate-for such misalignment and insure unobstructed entrance of the tumbler drivers into the radial bores of the casing during insertion and removal of the key, while retaining a close iit between the tumbler drivers and said radial bores in the casing to guard against any possible rotation of the cylinder except when the junctures of the tumblers and their drivers are in line with the line of parting between the cylinder-and casing bore.

EDWARD N. JACOBI.

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