FIELD OF THE INVENTION

The present invention relates generally to cylinder locks and particularly to a double cylinder lock actuated on the outer side with a key and on the inner side with a knob.

BACKGROUND OF THE INVENTION

Double cylinder locks are well known, which may be locked and unlocked from opposite sides of a door or window. Such a lock, commonly manufactured in a Euro profile cylinder, typically comprises two, separately actuable, axially aligned cylinders, each of which is connected to a cam located in a gap between the cylinders.

In some double cylinder locks, the outer cylinder includes a lock cylinder mechanism with a rotatable plug and an array of pin, disc or other tumblers, which can be brought to a shear line by insertion of a proper key for turning the rotatable plug. The inner cylinder has no pins or other locking elements, and instead is turned by a knob (the term “knob” encompasses a knob, thumb turn or other suitable mechanism).

In prior art cylinders, the cam can turn freely with the knob cylinder. An unauthorized object inserted in the keyway of the key-actuated side may block rotation of the knob cylinder.

SUMMARY OF THE INVENTION

The present invention seeks to provide an improved and novel double cylinder lock actuated on the outer side with a key and on the inner side with a knob, as is described more in detail hereinbelow.

The double cylinder lock of the present invention has a cam which may be initially prevented from rotating by means of a blocking element. Turning an authorized key inserted into the key way of the key side of the double cylinder lock will turn the cam to operate the lock. Turning the knob, without any need for additional actions (for example, without any need for pushing or pulling the knob) will override the blocking element and turn the cam to operate the lock.

In another aspect of the invention, even if an unauthorized object is inserted in the keyway of the key side of the double cylinder lock, turning the knob, without any need for additional actions (for example, without any need for pushing or pulling the knob) will override the unauthorized object and turn the cam to operate the lock.

There is thus provided in accordance with a non-limiting embodiment of the invention a double cylinder lock including a key-operated cylinder housing in which a key-operated plug with a keyway is disposed, a knob cylinder housing in which a knob mechanism is disposed, a rotatable cam located between the key-operated cylinder housing and the knob cylinder housing, and a blocking element initially in a blocking position with respect to the cam that prevents rotation of the cam, wherein the knob mechanism includes a knob coupled to a rotation transfer member, which is coupled to a cam-thrower element arranged to turn the cam, and wherein the rotation transfer member is coupled to a blocking element, such that rotation of the knob causes movement (e.g., rotation) of the rotation transfer member, which causes movement of the blocking element out of the blocking position with respect to the cam and enables rotation of the cam by rotation of the knob.

In accordance with a non-limiting embodiment of the invention the rotation transfer member is coupled to a key-pushing element, and rotation of the knob causes movement of the rotation transfer member, which causes movement of the key-pushing element towards the key-operated cylinder housing.

In accordance with a non-limiting embodiment of the invention the rotation transfer member is coupled to the blocking element by means of a pusher element which is arranged to abut against the blocking element

In accordance with a non-limiting embodiment of the invention the rotation transfer member is coupled to the key-pushing element by means of a pusher element which is formed with a bore and the key-pushing element is disposed in the bore

In accordance with a non-limiting embodiment of the invention the rotation transfer member includes an inclined surface on which a pin rests, the pin being affixed to the pusher element.

In accordance with a non-limiting embodiment of the invention the pin is guided to move in translation along a guide slot formed in the cam-thrower element.

In accordance with a non-limiting embodiment of the invention the key-pushing element is biased by a biasing device.

In accordance with a non-limiting embodiment of the invention, in the blocking position, the blocking portion is positioned between the cam and the key-operated cylinder housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Fig. 1 is a simplified pictorial illustration of a double cylinder lock, constructed and operative in accordance with a non-limiting embodiment of the present invention;

Figs. 2 and 2A are simplified side-view and sectional illustrations, respectively, of the double cylinder lock of Fig. 1, before the knob has been turned and with no key inserted in the key-operated side, with a blocking element initially blocking rotation of the cam, with Fig. 2A being taken along lines A-A in Fig. 2;

Figs. 3 and 3A are simplified side-view and sectional illustrations, respectively, of the double cylinder lock of Fig. 1, with the knob turned and with no key inserted in the key-operated side, thereby moving the blocking element out of the way to enable rotation of the cam, with Fig. 3 A being taken along lines A-A in Fig. 3;

Figs. 4 and 4A are simplified side-view and sectional illustrations, respectively, of the double cylinder lock of Fig. 1, before the knob has been turned and with an unauthorized object inserted in the key-operated side which initially blocks rotation of the cam by initially maintaining the blocking element in the blocking position, with Fig. 4A being taken along lines A-A in Fig. 4;

Figs. 5 and 5A are simplified side-view and sectional illustrations, respectively, of the double cylinder lock of Fig. 1, with the knob turned, thereby moving the unauthorized object and the blocking element out of the way to enable rotation of the cam, with Fig. 5A being taken along lines A-A in Fig. 5; and

Figs. 6A, 6B and 6C are simplified pictorial illustrations of a rotation transfer member that enables rotation of the knob to move the blocking element and/or any unauthorized object, Figs. 6A, 6B and 6C showing three positions of the rotation transfer member, respectively from the position that does not move the blocking element out of the blocking position (the pin has not yet been moved by the rotation transfer member and is furthest away from the cam), to a position in which the pin starts to move in order to cause movement of the blocking element, and to a pin position that fully moves the blocking element out of the blocking position (the pin moved by the rotation transfer member is closest to the cam).

DETAILED DESCRIPTION OF EMBODIMENTS

Reference is now made to Fig. 1, which illustrates a double cylinder lock 10, constructed and operative in accordance with a non-limiting embodiment of the present invention. Lock 10 includes a key-operated cylinder housing 12 in which a key-operated plug 14 with a keyway 15 is disposed. Lock 10 also includes a knob cylinder housing 16 in which a knob mechanism 18 is disposed.

The knob mechanism 18 may include a knob 20 coupled to a rotation transfer member 22, such as by means of a set screw or other fastener 23, or by being made as one unitary part with the rotation transfer member 22. The rotation transfer member 22 is coupled to cam-thrower element 24, such as but not necessarily, by means of one or more bearing elements 26 (such as, but not limited to, ball bearings), which protrude through holes 27 formed in cam-thrower element 24 and bear against the inner perimeter of knob cylinder housing 16 (as seen in Fig. 2A). The cam-thrower element 24 includes a dog 28 that can turn a cam 30 by abutting against a recess 32 formed in cam 30. In the illustrated embodiment, the rotation transfer member 22 is disposed in cam-thrower element 24, but this is not necessary for carrying out the invention.

The rotation transfer member 22 moves upon rotation of knob 20. In the illustrated embodiment, rotation transfer member 22 rotates upon rotation of knob 20. Alternatively, rotation transfer member 22 may be arranged to move in translation upon rotation of knob 20.

In the illustrated embodiment, rotation transfer member 22 includes an inclined surface 34 (which may be curved) on which a pin 36 rests. Pin 36 may be affixed to a pusher element 38, such as by being mounted through an aperture 39 formed in pusher element 38 (e.g., press fit). Pin 36 may be constrained or guided to move in translation along a guide slot 37 formed in cam-thrower element 24. The pusher element 38 may be formed with a central bore 35. It is noted that in the illustrated embodiment, rotation of the rotation transfer member 22 is converted into linear motion of the pusher element 38. This can be alternatively accomplished by screw thread mechanisms and other mechanisms.

The pusher element 38 may be arranged to abut against a blocking element 40 which has a blocking portion 42, such as but not limited to, a lug 42. Alternatively, pusher element 38 may be part of blocking element 40.

A key-pushing element 44 may be disposed in bore 35 of pusher element 38. The key-pushing element 44 may be biased by a biasing device 46, such as a coil spring.

The cam-thrower element 24 may be retained for rotation in knob cylinder housing 16 and the rotatable plug 14 may be retained for rotation in key-operated cylinder housing 12 by circlips 45 and 47, respectively. Reference is now made to Figs. 2 and 2 A, which illustrate the double cylinder lock 10 before the knob 20 has been turned and with no key inserted in the key-operated side. It is seen in Fig. 2A that the blocking portion 42 of blocking element 40 initially blocks rotation of the cam 30, because the blocking portion 42 is positioned between (straddles) the cam 30 and the key-operated cylinder housing 12. This is referred to as the blocking position because in this position cam 30 is blocked from rotation by blocking element 40. This is the initial position of the lock 10.

Reference is now made to Figs. 3 and 3 A, which illustrate the double cylinder lock 10 with the knob 20 turned and with no key inserted in the key-operated side. It is seen in Fig. 3A that turning knob 20 causes the pin 36 of pusher element 38 to slide or move along inclined surface 34 of rotation transfer member 22, so that pin 36 moves linearly in guide slot 37 towards the cam 30. This movement of pin 36 causes the pusher element 38 to push against blocking element 40, so that the blocking portion 42 of blocking element 40 is moved away from cam 30 further into the key-operated cylinder housing 12. The blocking portion 42 of blocking element 40 has now been pushed out of the blocking position to enable rotation of the cam 30 by turning knob 20.

Thus, the invention solves one of the problems of the prior art: the blocking element 40 prevents turning of the cam 30 by a picking tool that bypasses the key- operated lock cylinder, yet allows turning of the knob 20 to actuate cam 30 by a person inside the room.

The movement of pin 36 along inclined surface 34 can be seen in Figs. 6A, 6B and 6C, which illustrate three positions of the rotation transfer member 22. Fig. 6A shows the pin 36 furthest away from the cam (not shown in Fig. 6A). This is the position that does not move the blocking element out of the blocking position, as in Fig. 2A. Fig. 6B shows the pin 36 in the position that starts to move the blocking element (not shown in Fig. 6B). Fig. 6C shows the pin 36 moved closest to the cam (not shown in Fig. 6C), which is the position of Fig. 3A in which the blocking element is fully moved out of the blocking position.

It is noted that insertion of an authorized key in the key side of lock 10 will bring the cylinder lock to the shear line and turning the key will rotate the plug. The blocking element and the cam will rotate together with the plug. Thus, turning an authorized key inserted into the key way of the key side of the double cylinder lock 10 will turn the cam to operate the lock 10. Reference is now made to Figs. 4 and 4 A, which illustrate the double cylinder lock 10 before the knob 20 has been turned and with an unauthorized object 50 inserted in the key-operated side. The term “unauthorized object” includes any object, such as but not limited to, a key or any foreign object, which does not bring the cylinder lock to the shear line. Just as in Fig. 2A, the blocking portion 42 of blocking element 40 blocks rotation of the cam 30, because the blocking portion 42 is positioned between the cam 30 and the key-operated cylinder housing 12. It is also seen that insertion of unauthorized object 50 pushes key-pushing element 44 further into bore 35 of pusher element 38, which compresses biasing device 46. In this position, cam 30 is blocked from rotation.

Reference is now made to Figs. 5 and 5 A, which illustrate the double cylinder lock 10 with the knob 20 turned. It is seen in Fig. 5A that turning knob 20 causes the pin 36 of pusher element 38 to slide or move along inclined surface 34 of rotation transfer member 22, so that pin 36 moves linearly in guide slot 37 towards the cam 30. This movement of pin 36 causes the pusher element 38 to push against blocking element 40, so that the blocking portion 42 of blocking element 40 is moved away from cam 30 further into the key-operated cylinder housing 12. In addition, pusher element 38 pushes against key-pushing element 44, which causes key-pushing element 44 to push against and move unauthorized object 50 further out of the key-operated cylinder housing 12. The blocking portion 42 of blocking element 40 has now been pushed out of the blocking position to enable rotation of the cam 30 by turning knob 20.

Thus, the invention solves one of the drawbacks of the prior art: even if an unlawful person inserts unauthorized object 50 in the keyway of the key-actuated side, turning of the knob 20 causes the key-pushing element 44 to move unauthorized object 50 further out of the key-operated cylinder housing 12 and the cam 30 can be turned by knob 20.