Padlock And Key Cylinder Release

Abstract

Padlock having plunger releasably holding key cylinder to padlock casing and accommodating quick change of the key cylinder. The padlock casing has parallel bores for the shackle, one of which bores is of a lesser depth than the other. The key cylinder is carried in the casing for the lock between the bores and terminates beneath the bottom of the bore of lesser depth. The bore of lesser depth is counterbored to afford access to a plunger guided for movement transversely of the key cylinder and biased outwardly of the key cylinder into the counterbore to hold the key cylinder to the casing. A washer having a quadrant extending inwardly therefrom retains the key plug to the key cylinder. The surface of the key plug intercepts the plunger and prevents depression thereof and release of the key cylinder when the key plug is in a locked condition. A slot for the washer and quadrant affords access of the plunger to the key plug, to be depressed within the slot when the key plug is in an unlocked position. Access is afforded to the outer end of the plunger by a thin screwdriver or other tool upon removal of the short leg of the shackle from its bore.

Description

FIELD OF THE INVENTION

Padlock and quick change means for the key cylinder and plug of the lock.

BACKGROUND, SUMMARY AND ADVANTAGES OF INVENTION

Heretofore, the key cylinders of padlocks have been interchangeably mounted in the casing for the padlock by a screw threaded in the key cylinder and casing and accessible through the shallow shackle bore of the casing. The screw is relatively small and the shallow shackle bore is usually drilled to accommodate the screw to be threaded through the bottom of the bore into the key cylinder making it difficult to release the screw. The removal and replacement of key cylinders of padlocks to change the tumbler combination is thus a relatively tedious and time-consuming operation, and the key cylinder can be removed when the shackle is out of its bore regardless of whether the key plug is turned to release the lock.

In accordance with the principles of the present invention, a plunger depressible within a side wall of the key cylinder engages the bottom of a counterbore of a shackle bore to hold the key cylinder to the padlock casing. A washer recessed in the key cylinder and having a retainer formed as a part thereof and extending into a slot in the key plug retains the key plug to the key cylinder. The wall of the key plug prevents depression of the plunger and removal of the key cylinder except when a key has turned the key plug into an unlocked position and registers the slot with the plunger to accommodate the plunger to be depressed within the slot and key cylinder.

An advantage of the present invention, therefore, is in the simplicity of the retainer for retaining the key cylinder to the padlock casing, enabling quick release of the key cylinder from the casing to accommodate the changing of the key cylinders having different tumbler pin combinations.

A further advantage of the present invention is the fact that the key cylinder may be released by the simple depression of a plunger within the margins of the key cylinder, out of retaining engagement with the padlock casing.

Still another advantage in the invention is in the retainer washer for retaining the key plug to the key cylinder and accommodating release of the key cylinder from the padlock casing when the key has turned the key plug to an unlocked condition.

Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a padlock constructed in accordance with the principles of the present invention.

FIG. 2 is a transverse sectional view taken through the padlock shown in FIG. 1, showing the padlock in a locked condition.

FIG. 3 is a partial fragmentary sectional view taken through the padlock casing, key cylinder and key plug substantially along line III--III of FIG. 2, and illustrating the key plug in a locked position in the key cylinder and padlock casing.

FIG. 4 is a view somewhat similar to FIG. 2 but showing the shackle in an unlocked release position and showing the use of a tool for depressing the locking plunger for the key cylinder; and

FIG. 5 is a partial fragmentary sectional view taken substantially along line V--V of FIG. 4 illustrating the release of the locking plunger from the padlock casing to accommodate removal of the key cylinder for changing key cylinders.

DESCRIPTION OF PREFERRED EMBODIMENT OF INVENTION

In the embodiment of the invention illustrated in the drawings, I have shown in FIG. 1 a padlock including a casing 10 having a shackle 11 generally U-shaped in form with a key cylinder 12 carrying a key plug 13 on the opposite end of the casing from the shackle. The key plug 13 has a slot for a key 15 opening to the bottom of said key plug.

As shown in FIGS. 2 and 4, the casing 10 has parallel bores 16 and 17, one of which is deeper than the other, for legs 18 and 19 of the shackle 11. A compression spring 20 seated in the bottom of the bore 16 biases the shackle 11 upwardly out of locking engagement with the casing 10 upon the release of the lock. The leg 18 has an annular recess 21 extending thereabout and adapted to be engaged by a retainer pin 22 for retaining the shackle to the casing when the padlock is unlocked.

The legs 18 and 19 also have arcuate recesses 23 and 24 in the inner sides thereof of different elevations and adapted to be engaged by balls 25 and 26 in a transverse angularly extending passageway 27. The balls 25 and 26 are engaged with the recesses 23 and 24 to lock the padlock by engagement with the cylindrical wall of the locking member 28 rotatably mounted in a central bore 29 extending along the padlock casing from the bottom thereof. The cylindrical wall of a locking member has diametrically opposed flattened portions 30,30 which when registered with the balls accommodate retraction of the balls along the passageway 27 to accommodate opening of the padlock by outward pulling movement of the shackle, to withdraw the short leg 19 from the bore 17, and then turn the leg and shackle about the axis of the leg 18.

As shown in FIGS. 2 and 4, the locking member 28 has a reduced diameter lower end portion 32 having a torsion spring 33 extending thereabout and secured to the bottom of said locking member at one of its ends and to a stationary plate or washer 35 at its opposite end. Said washer is suitably mounted in a central bore for the locking member and held from rotation with respect thereto by a tab 34. The reduced diameter end of the locking member 28 has a sector 37 depending therefrom beneath the washer 35 and relatively movable with respect thereto. The sector 37 has a flat diametrically extending inner face engageable with a flat diametrically extending inner face 39 of a sector projecting upwardly of the key plug 13. Turning movement of the key plug 13 in one direction by the key 15 will thus move the locking member to its release position shown in FIG. 4, while turning movement of said key plug in an opposite direction will force the balls 25 and 26 outwardly into position to engage within the recesses 23 and 24 and hold the shackle in its locked condition.

Referring now in particular to the means for retaining the key cylinder 12 and the key plug 13 to the casing 10, the key cylinder 12 is shown as being generally figure-8 in form and including a solid portion 40, drilled to receive the inner pin parts of tumbler pins (not shown), and as having a hollow portion 41 forming a generally cylindrical socket for the key plug 13 carrying said key plug for rotatable movement with respect thereto to lock and unlock the padlock.

The key plug 13 is of a conventional form having a key slot 42 extending therealong and affording access to a series of tumbler pins (not shown) engageable with corresponding spring biased tumbler pins in the solid portion of the key cylinder 12. The key 15 when inserted in the key slot 42 serves to depress the tumbler pins in the solid part of the key cylinder flush with the periphery of the key plug to accommodate turning movement of the key plug relative to the key cylinder, in a manner well known to those skilled in the art and no part of the present invention, so not herein shown or described further.

The key plug has a transverse slot 43 extending thereacross adjacent the upper end thereof, registrable with a transverse slot 44 in the wall of the hollow part 41 of the key plug. A semi-circular washer 45 fits in the slot 44 and is provided to retain the key plug to the key cylinder. As shown in FIGS. 3 and 5, the semi-circular washer 45 has a sector 47 extending into the slot 43 and the key plug, and retaining the key plug to the key cylinder, it being understood that the washer 45 is retained in the key plug by the cylindrical wall of the bored portion of the key cylinder forming a socket for the key plug.

The locking means for locking the key cylinder to the casing 10 is in the form of a plunger 48 slidably mounted in a transverse hole 49 in the key cylinder 12. The transverse hole 49 terminates into a small diameter hole 50 leading to the key plug 13 in horizontal alignment with the slot 43. The plunger 48 has a stem 51 extending inwardly therefrom within the reduced diameter hole 50 and of sufficient length to pass into the slot 43 to accommodate complete retraction of the plunger 48 within the wall of the key cylinder 12 and thereby accommodate the removal of the key cylinder and key plug from the padlock casing when the key cylinder is in its unlocked condition. A compression spring 53 is seated at one end in the bottom of the drilled portion 49 and on the shouldered portion of the plunger 48 at its opposite end, and biases the plunger to extend over a bottom wall 55 of a counterdrilled portion 56 of the bored or drilled portion 17 of the casing 10. The counterdrilled portion is of a smaller diameter than the diameter of the drilled or bored portion 17 and accommodates a relatively thin tool 57 to be passed therein and engage the end of the plunger 48 and depress said plunger within the key cylinder to clear the internal wall of the hollow portion of the key cylinder, as shown in FIG. 4, and thereby accommodate the key 15 to pull the key plug and cylinder from the casing 10.

In FIG. 3, the key plug is shown in its locked position and the plunger 48 is shown in its extended position locking the key cylinder to the casing 10. In this position of the key plug, the cylindrical wall portion of the key plug will prevent release of the plunger 48 from the bottom 55 of the counterdrilled hole 56.

When, however, the key plug is turned by the key 15 to its unlocked position to position the locking member 28 in the position shown in FIG. 4, the key plug 13 will be turned into position to accommodate the stem 51 to pass into the slot 43, as the thin tool 57 is pressed against the end of the plunger 48. With the key 15 in the key slot, the key may exert a withdrawing force on the key plug and key cylinder and thereby withdraw the key cylinder from the lock casing to be replaced by another key cylinder having a different tumbler combination.

It may be seen from the foregoing that a simple release for the key cylinder of a padlock has been provided, accommodating quick removal of the key cylinder to be replaced by a key cylinder having a different tumbler combination by merely unlocking the padlock and withdrawing the short leg of the shackle from its bore 17 and depressing the plunger 48 by a tool 57 until the plunger clears the wall of the bore for the key cylinder, and then withdrawing the key cylinder for replacement with another key cylinder of a different tumbler combination.

Claims

I claim as my invention:

1. In a padlock,

a casing,

a shackle having a plurality of parallel legs guided in said casing,

one of said legs being movable outside of said casing to accommodate opening of the lock,

locking means for locking said shackle in a locked condition in said casing,

means for releasing said locking means including

a key cylinder mounted in said casing,

a key plug rotatably carried in said cylinder and operable by turning movement of a key to release said shackle and accommodate one leg thereof to move out of said casing,

and means retaining said key cylinder in said casing and accommodating release thereof for changing the key cylinder for a key cylinder having a different tumbler combination, comprising a plunger guided in said key cylinder into locking engagement with said casing,

said plunger having an inner reduced diameter stem portion, engageable with said key plug when in a locked position,

a spring encircling said stem portion and biasing said plunger into retaining engagement with said casing, and

said key plug having a slot therein receiving said stem only when said key plug and the locking means operated thereby are in an unlocked condition, to accommodate depression of said plunger and withdrawal of said key cylinder from said casing.

2. The padlock of claim 1,

wherein the slot is in the form of a sector of a circle,

wherein a retainer washer is recessed in said key cylinder in alignment with said slot,

wherein said washer has a portion extending into said slot to retain said key plug to said key cylinder,

and wherein said portion is positioned to accommodate said stem to move into said slot to accommodate release of said plunger from said casing, when said key plug is turned into position to unlock the lock and release the shackle.

3. In a padlock,

a casing having parallel bores extending therealong for a portion of the length thereof,

a shackle having parallel legs guided in said bores,

locking means locking said shackle in said bores and accommodating movement of one leg of said shackle outside of a bore to release the lock,

a key cylinder mounted in said casing between said bores and extending in the direction of said bores and having a key plug therein,

retainer means for said key cylinder operable to retain said key cylinder to said casing and to release said key cylinder from said casing, only when said locking means is in a release position, to accommodate the changing of key plugs and cylinders having a different tumbler pin arrangement comprising a plunger slidably guided in said key cylinder transversely of the axis thereof and having interengagement with said casing to lock said key cylinder to said casing,

one bore being of a lesser depth than the other and a counterbore extending into said bore of lesser depth and having a bottom wall forming an abutment for said plunger,

said plunger having a reduced diameter inner stem portion engageable with said key plug when said key plug and the locking means operated thereby are in a locked position,

a spring biasing said plunger into engagement with said counterbore, and

said key plug having a slot therein receiving said stem when the locking means locked by said key plug is in a release position, and accommodating release of said plunger from said counterbore, only when the key plug and locking means operated thereby are in a release position.

4. The padlock of claim 3,

wherein the slot is in the form of a sector of a circle, and

wherein a retainer washer is recessed in said key cylinder in alignment with said slot and has a quadrant extending in said slot to retain said key plug to said key cylinder, said key plug being movable into position to register said stem portion with said slot, to accommodate a tool to depress said plunger against the bias of said spring when said key plug and the locking means operated thereby is in an unlocked position and permit withdrawal of the key cylinder and plug.