US2073583A - Removable lock - Google Patents

Description

2 Sheets-Sheet l INVENTOR.

ATTORNEY.

March 9, 1937. v P. w. OLSON REMOVABLE LOCK Filed June 10, 1955 (0'. Olson March 9, 1937. P. w. OLSON REMOVABLE LOCK Filed June 10, 1935 2 Sheets-Sheet 2 1 N VENTOR. Pfizigia (fl. Oboil %44MW ATTORNEY.

Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE REMOVABLE LOCK Application June 10,1935, Serial No. 25,709

8 Claims.

This invention relates to improvements in locks, and more particularly to the provision of releasable means for retaining the tumbler plug in the lock casing barrel.

It is often desirable to change looks so that the old keys can no longer be used, and in some instances it has been necessary to change all of the locks in large buildings owing to a general change in tenants. Such instances involve the removal and replacement of several thousand lock plugs, and consequently a large expense accumulates. Accordingly one object of this invention is to provide a lock having a readily removable plug, but which to prevent illicit removal requires the use of a specially formed removal key, and also the operation of other instrumentalities, as well as a knowledge of the particular manner of removing.

Further objects of the invention are to provide a plug retaining construction in which the plug is not apt to become released in the normal service operation of the lock; to provide such means which can be operated entirely from the face of the look so that it is not necessary to open the door to obtain access to screws or pins in the edge or inner side of the door; and to provide means for releasably retaining the plug which is entirely under the protection of the lock itself, whether the door is open or closed.

' Other objects and advantages will become apparent in the following description, taken with reference to the accompanying drawings, in which an illustrative embodiment of the invention is shown.

Fig. 1 is a longitudinal cross section of the key operated locking unit which, as in well known practice, is inserted in the door or the fastening mechanism of other forms of closures; Fig. 2 is a transverse cross section, looking from the rear, taken on the line 2-2 of Fig, 1;

Fig. 3 is a transverse section on the line 3-3 of Fig. 1;

Fig. 4 is a front elevation of the unit; Fig. 5 is a longitudinal section of the barrel or housing member;

Fig. 6 is a section taken on the line 66 of Fig. 1 with the plug sectioned on the two different planes of the tumblers;

Fig. 7 is a. diagrammatic view showing the master key operation; and

Fig. 8 is a similar diagrammatic view showing the operation of the tumblers by the insertion of the replacement key.

A cylindrical barrel housing or casing 9 is provided, which has a stepped concentric counterbore NJ in the rear end thereof; an eccentric plug receiving bore II; and a smaller bore [2, below the bore I I, both of which extend through the barrel.

Seated in the bottom of the counter-bore l0 is a stationary plate l3, secured in position by means of screws l4; and an end cover plate [5 is secured in the end of the barrel by peening over the metal at the edges.

In the installation, the barrel is fixedly mount- 10 ed in position, which may be accomplished in any well known manner.

In the outer face of the barrel is a stepped counter bore l6, concentric with the bore H, for receiving a keyhole plate I! which is mount- 15 ed on the outer end of a cylindrical tumbler plug I8; and in the walls of the bore H is provided a plurality of annular grooves l9 and a pair of offset, oppositely disposed longitudinal grooves 20. bottom of the counter bore l0 into the counter bore I6 and intersect each of the ridges 2| between the annular grooves 19. A small pocket 22 is also provided in the rear portion of the bore I! and intersecting the bore l2 to provide 5 space for a plug retainer cam 23.

' Thus the plug I8 is inserted in a bore having annular circumferential grooves intersected by longitudinal grooves forming notches 24, which provide locking surfaces for preventing the rotation of the plug. The plug is provided with a set of latch key tumblers 25, which normally register with the ridges 2| and engage in the notches 24 to lock the plug against rotation.

Latch tumblers 25 are arranged in a row along 35 one side of a keyway 26, which extends longitudinally through the plug l8 and the plate l1; and at the opposite side of the keyway is provided a set of master key tumblers 21, which normally register in the grooves l9 and abut 40 against the sides thereof, and prevent endwise movement of the plug.

The tumblers are all similar in construction, except for variations in certain dimensions to provide the different series of combinations. 45 Each tumbler has a lug 28, which projects into the keyway 26; and the tumblers are individually pressed outwardly to project from the surface of the plug in one direction or the other by means of small springs, which are inserted in notches 50 280,, provided in the outer edges of the tumblers, and seat against pins 29 inserted through the 1 walls of the plug.

Thus in service operation the set of tumblers 25 may be withdrawn into the plug by the inser- 55 Said grooves 20 extend from the tion of a latch key, not shown, which is provided with grooves having suitable deviations for so operating the tumblers. The plug may then be rotated to operate the look by means of the cam 39, which is provided at the rear end of the barrel.

The cam 38 is fixedly mounted on the shaft 34 of a gear 35, which is confined between the plates I3 and i5 and meshes with a gear 35, which is provided with a hub 31, which extends through the plate I3. The hub 31 is provided with a tongue 38 which enters the keyway at the rear end of the plug.

In this manner the axis of the cam may be located in the lower portion of the barrel, while the plug is mounted in the upper portion. The plug is urged forwardly by means of a bifurcated spring plate 353, which is riveted to the inner side of the plate l3 and straddles the reduced inner end portion 49 of the plug and bears against a shoulder 44 formed on the plug.

The shoulders of the tongue portion 38 of the gear hub 37 are located far enough back, and the depths of the counterbore I6 is such that the plug may be pushed into the barrel against spring 39 when the master key tumblers 27 are drawn inwardly. This moves the tumblers 25 into the annular grooves l9 so that the plug is then free for rotation, in the master key operation of the look.

For preventing endwise withdrawal of the plug when a master key 42 is inserted, a retainer tumbler 43 is provided which engages behind a ring 44, which is fixedly mounted in the inner portion of the bore l I and surrounds the plug, as clearly shown in Fig. l and Fig. 3. Accordingly the plug cannot be withdrawn until a replacement key45, which has a groove 45a for withdrawing the master key tumblers, which groove is extended to also withdraw the retainer tumbler 43; but toremove it, the plug must be rotated into lockin normal position so that the latch key tumblers 25 will pass out through the longitudinal grooves 29.

As will be understood, the master key 42 is shouldered so that it cannot be inserted to a sufficient depth to operate the tumbler 43, or the end portion of the groove 42a in the master key may be formed so that it does not fully withdraw the tumbler 43.

In addition to the above described releasable plug retaining means, I provide the cam 23 which is keyed on the inner end of a rod or shaft 55, which is inserted in the bore l2.

On the inner portion of the plug i8 is provided a circumferential groove 46 for the engagement of the cam 23, and the bottom of the groove is flattened at one side of the plug to provide a depression 41 (Fig. 3) for permitting the rotation of the cam when the plug is rotated to bring the depression 4? opposite and into registration with the end 48 of the cam which is made concave to closely cooperate with the circular bottom portion of the groove. The cam is urged to rotate into engagement in the groove by a coil spring 49, and

is provided with a stop projection 59, which strikes against the wall of the pocket 22, as clearly shown in Fig. 3, and governs the position of the cam so that the end portion thereof does not bear against the bottom of the groove 45 and interfere with the turning of the plug in ordinary service operation.

The front end of the shaft 55 has a transverse slot 49 for receiving a bladed tool for turning the shaft to disengage the cam 23. In order to prevent the use of any kind of an implement, such as a screw driver, a slotted plate 59 may be secured in the opening of the bore I2.

Thus to remove the tumbler plug, the replacement key 45 which fits the lock must be inserted in the keyway to withdraw the master key tumblers 21 and the retainer plunger 43. Then the plug is pushed rearwardly against the action of the spring 39 to move the latch key tumblers 25 out of the notches in the ridges 2| and into the circumferential grooves l9. This frees the cylinder plug l8 for rotation, and the key is turned to bring the depression 41 opposite the cam so that the cam may be rotated.

While the key is being held in this position with one hand, a bladed tool is inserted through the orifice plate 5|] and engaged in the slot 49 to rotate the cam 23 clockwise, looking from the front against the action of the spring 49.

Accordingly the cam must be held out of engagement until the tumbler plug is turned back to normal position so that the row of latch key tumbler wells pass out through the longitudinal slots 29.

With the proper tools, it is manifest that the locks can be changed easily and quickly, while at the same time unauthorized removal of the plug is very difficult to accomplish.

Having thus described my invention, I claim:

1. In a lock having a barrel and a key operated tumbler cylinder mounted in the barrel for rotation, the cylinder having a peripheral groove having a depression in its bottom surface and a cam rotatably mounted in the barrel adjacent the cylinder, the cam being rotatable into or out of engagement in said groove when the cylinder is rotated to bring said depression opposite the cam, and the cam having a concave end surface cooperating with the bottom of the groove to prevent its rotation when the said bottom depression is not in registration therewith.

2. In a lock having a barrel and a key operated tumbler cylinder mounted in the barrel for rotation, the cylinder having a peripheral groove having a depression in its bottom surface, a cam rotatably mounted adjacent the cylinder for engaging in said groove to prevent withdrawal of the cylinder, the cam having a concave end surface for cooperating with the bottom of the groove for locking the cam in engagement, a spring for rotating the cam into the groove, and a stop governing the locking position of the cam so that said end surface is held out of friction producing contact with the bottom of the groove.

3. A look comprising a barrel having annular and longitudinal intersecting grooves in the walls thereof, a key operated plug inserted in the bore, a spring pressing the plug forwardly, the plug having a set of latch key tumblers normally registering with the ridges between the annular grooves and engageable in the notches formed by the longitudinal grooves in said ridges, and the plug having a set of master key tumblers nor mally registering in the grooves to prevent longitudinal movement of the plug, a ring fixedly mounted in the rear portion of the bore, and a plug retaining tumbler contained in the plug for engagement behind the ring so that the plug can only be removed by withdrawing the master key and. the plug retaining tumblers and placing the plug in locking position so that the latch key tumblers will pass out through the longitudinal grooves.

4. The combination of claim 3 further including other retaining means normally engaged with the plug and releasable therefrom only when the plug is rotated away from locking position.

5. A look comprising a barrel having annular and longitudinal intersecting grooves in the walls thereof, a key operated plug inserted in the barrel, a set of latch key tumblers in the plug normally registering with the ridges between the annular grooves and engageable in the notches formed by the longitudinal grooves in the ridges, a set of master key tumblers normally registering in the grooves to prevent longitudinal movement of the plug, the plug also having an annular groove at its innermost end, a cam mounted in the barrel and having a shaft upon which it is rotatable extending to the front of the barrel for operating the cam from the face of the barrel to release the plug for removal from the barrel when the master key tumblers are withdrawn.

6. A look comprising a barrel having annular and longitudinal intersecting grooves in the walls thereof, a key operated plug inserted in the barrel, a spring pressing the plug forwardly, the plug having a set of latch key tumblers normally registering with the ridges betweenthe annular grooves and engageable in the notches formed by the longitudinal grooves in said ridges, a separate set of master key tumblers normally registering in the grooves to prevent longitudinal movement of the plug, the plug having an annular groove at its inner end and means including a cam mounted in the barrel at the side of the plug and rotatable from the front of the barrel for normally engaging in thegroove of the plug, the groove being of suflicient width to maintain engagement with the cam when the plug is pressed longitudinally against the spring a distance equal to the Width of the ridges within the barrel.

7. A structure in accordance with claim 6 in which the plug has a keyway extending through it, and a plug operated member is mounted at the rear of the barrel and includes a hub having a tongue which enters the keyway at the rear of the plug for operative movement therewith.

8. In a lock having a barrel and a key operated tumbler cylinder rotatably mounted in the barrel, the cylinder having a peripheral groove at the inner end thereof, a cam rotatably mounted adjacent the cylinder for engaging in said groove to prevent withdrawal of the cylinder, and means extending within the barrel from the cam toward the front of the barrel with a transverse slot in the end thereof which lies at a distance within the barrel for receiving a bladed tool inserted from the front of the barrel for operating the cam.

PHILLIP W. OLSON.

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