US3319443A - Lock cylinder - Google Patents

Description

R.y PERLICK LOCK CYLINDER Filed March 22, 1955 May 16, 1967 INVENTOR Rem/101.9 PzRL/c/f United States Patent 3,319,443 LOCK CYLINDER Reinhold'Perlick, Velbert, Rhineland, Germany, assignor to Yale & Towne G.rn.b.H., Velbert, Rhineland, Germany, a corporation of Germany Fiied Mar. 22, 1965, Ser. No. 441,633 6 Claims. (Cl. 70-421) ABSTRACT GF THE DISCLOSURE A lock tumbler cylinder in which a rotatable key plug is mounted in a lock operating sleeve that has a loose segment at the keyway of the key plug. When a tool is inserted into the keyway for jamming the sleeve to the key plug, the tool will merely jam the sleeve segment to the outer cylinder body so that tumbler picking torque cannot be applied through the sleeve to tumblers conrolling rotation of the sleeve. The segment further insures the etfect of a yielding detent that normally holds the sleeve in locking position.

The present invention concerns a lock cylinder with a key plug of known construction carried rotatably in the cylinder housing and having radially displaceable tumbler pins and a coupling tube rotatably carried between the cylinder housing and the key plug, and presenting the feature that the coupiing tube is restricted in its turning in relation to the cylinder housing by a braking element.

It is possible to defeat the usual lock cylinder by applying torque to the key plug so as to take up lateral play between the tumbler pins and the bores in which they move in the key plug and housing. The tumbler pins then are displaced one at a time by a suitable tool inserted in the keyway, until each pin engages the housing at the parting line between the housing and key plug. It is then possible to rotate the key plug.

In order to increase the security of lock cylinders, it is already known to provide between the cylinder housing and the key plug a rotatable coupling tube on which is the lock operating cam. The coupling tube has several radial bores for the tumbler pins, and is normally blocked against turning by the pins. Certain of the tumbler pins have rounded ends, so that it is more ditiicult to place the key plug under stress during a picking operation. However, the coupling tube can also turn with the key plug, and therefore it is possible with sufficient skill to bring the tumbler pins to the line dividing the tube and the housing so that the lock, in spite of these measures, can be operated.

Acordingly, attempts have already been made to prevent the unauthorized operation of lock cylinders, as by making the keyway comparatively narrow. However, the keyway must have sutcient width to allow the use of a key of the necessary strength. Also, even when narrow, the keyway still permits the unauthorized insertion of a suitable picking tool. Also, by the known method of forming the tumbler pins mushroom-shaped, the picking process can only be made difficult, but not prevented with any certainty.

By my invention, I am able to construct a lock cylinder with a key plug rotatably carried in the cylinder housing, having several radially displaceable tumbler pins and a coupling tube rotatably carried between the cylinder housing and the key plug and carrying the operating cam. which does not show the above-mentioned disadvantages. Rather, it is constructed in such a way that it is substantially secure against unauthorized operation. For this purpose, the invention provides that the coupling tube is restricted by a braking element in its turning in relation to the cylinder housing. A lock cylinder of this type can only be operated with the properly constructed key and not with picking tools of the usual type. In the rst place all the tumbler pins are so set by the key that their contact points are at the cylindrical separating line between the cylinder housing and the coupling tube, so that accordingly the pins lie across the separating line between the coupling tube and the key plug, and the tube and the key plug are coupled together. On operation of the cylinder, accordingly not only the key plug but also the coupling tube is turned, against the action of the restricting braking element. On the other hand, if an attempt is made to pick the tumblers, the cylindrical key plug can still be put under stress, that is to say turned slightly in relation to the housing, but the coupling tube will not turn with it, as this tube is prevented with certainty from doing so by the braking element acting on the tube. Accordingly, when picking torque is applied to the key plug, a picking tool can merely set the tumblers at the cylindrical separating line between the coupling tube and the key plug, with the result that only the key plug, but not the tube carrying the operating cam, is turned, and the cylinder cannot be operated.

In my preferred construction, the 'braking element consists of a detent sphere disposed in the cylinder housing and pressed by a spring, which in the locking position of the coupling tube engages in a recess provided in the wall of the tube, with the result that the brake effect arises in practice only in the locking position of the coupling tube, whereas the tube can rotate during the normal operation.

As an important feature of my invention, I construct my cylinder with means that will prevent the key plug becoming jammed up in relation to the coupling tube by a specially constructed opening tool, with consequent entrainment of the tube if torque is applied to the key plug. As a detailed part of this feature, the coupling tube has at its side adjacent to the keyway in the cylinder core a longitudinal opening in which a segment-shaped insert is loosely carried. In this way, it is ensured that any clamping forces applied at the keyway side are directly transferred to the cylinder housing by the loosely carried insert, and accordingly there are adhering forces applied between the coupling tube and the cylinder housing so as to overcome the clamp forces between the tube and the key plug.

The invention will now be described in reference to the attached drawings, which show an embodiment but in no restrictive sense.

FIGURE 1 shows the lock cylinder of the invention with the key inserted, in longitudinal section.

FIGURES 2 and 3, show a cross-section of the cylinder withinserted key and with an inserted picking tool.

The lock cylinder shown has a cylinder housing 1 and a cylindrical key plug 2 constructed in the usual way and rotatably disposed therein, which key plug is provided with several tumbler pin bores 3 and a keyway 4, for the insertion of a key. In the pin bores 3, tumbler pins 5 are slidably provided, which are in engagement with corresponding tumbler pins 6 which are disposed slidably in the openings 7 provided in the cylinder housing 1. The openings 7 are covered externally by a lock casing 8 surrounding the cylinder housing 1. When the key 9 is withdrawn, the housing pins 6 under the action of the springs 10 project partly into the pin holes 3 of the cylindrical key plug 2.

Between the cylinder housing 1 and the key plug 2 there is rotatably carried a cup-shaped coupling tube 11, which at its inner end 11 is provided with a shaft 12 for the closing cam 13, by which the lock, which is not shown in detail, can be operated. Further, the coupling tube 11 has radial bores 14 for the tumblers 5, 6. The rotation As can be seen from FGURES 1 and 2, by the ini sertion of the key 9 into the keyway d, the tumblers S, o are raised to the exent that thel contact points between the key plug pins and the housing pins e are aligned With the cylindrical separating line formed by the cylinder housing 1 and the coupling tube il.. At the same time, the key plug 2 and the tube ll are coupled together by the key plug pins 5. When rotated by the key, therefore, not only the cylindrical key plug 2 is turned, but also the coupling tube ll, the lock being operated by the closing `cams 13 carried by the tube.

If a person seeks to operate the cylinder without the proper key, he first will apply torque to the cylindrical key plug 2, as by utilizing a picking tool i7, FlG. 3. Thattorque will rotate the key plug 2 a slight amount, andinitially only to the extent permitted by the lateral play that may exist between the tumbler pins o and the tumbler bores 3;, ld, and 7. The coupling tube lll on the, other hand' will not rotate because the tube will be held by the detent sphere 14a engaging in its recess l5., Therefore,4 while the torque will cause lateral pressures. on the tumblers 6,- those pressures will not be eil'ective. between the cylinder openings 7 and coupling tube,

openings 14. If the tumblers then are moved in an at-U tempt to detect their proper setting, the lateral pressures that are applied to the tumblers may be useful only to detect a setting of the tumblers at the line be-A tween key plug l2 and coupling tube il, as shown for ex ample in FG. 3. Through that procedure, it may be. possible to set the tumblers so that the cylindrical key plug 2 can freely turn, but on the other hand, the coupling: tube l with its connected cam cannot turn, and accord-- ingly it is not possible to operate the cylinder. When the key plug 2 has turned through 360, the housing. pins 64 again fall into the bores 3 of the cylindrical kegl ping 2 so that the key plug again is locked.

In order to prevent the `cylindrical key plug '/L being: jammed up in relation to the coupling tube ll by the insertion of a tool in the keyway nl, that is to say to pre vent the entrainment of the tube when torque is applied to the plug, the coupling tube lll has on its side adjacent, to the keyway 4 a longitudinal slit i8 in which there is loosely carried a segment-shaped insert l. More partie-- ularly, a person attempting to detect the proper tumbleru setting may believe that he can jam the key plug and'. al lower part of the coupling tube il to one another at the keyway 4i, in effect connecting tube ll and key plug 21 so that they will rotate together, and defeating the pur-- pose of tube lll. However, in trying to iam the key plug;

- and tube, a person will press the segment shaped insert 1 9 in a downward direction against the housingT l, so that insert 19 a-ctually will oppose all rotating movements, Moreover, this insures that the detent Ma will eiectively hold the coupling tube lll, so that the tube will not be rotated when torque is applied for the purpose Oi detecting the tumbler setting.

The coupling tube llll is covered at its outer end lll and at the surface 11 of its inner end il', by discs of tempered steel 2u and 2l, which ensures that between the key plug 2 and the tube 1l no constant coupling can be produced, for example by boring the key plug and inserting a tool.

I now claim:

1. In a combination of the class described, a lock cylinder, a sleeve rotatable in a bore of said cylinder, means on said vsleeve for operating a lock when said sleeve is rotated, a key plug rotatable in said sleeve and having a longitudinal keyway terminating in a longitudinal slot on the outer surface of the key plug, a series of tumblers controlling the rotation oi said key plug relatively to a locking position in said sleeve and the rotation of said sleeve relatively to a locking position in thev bore of said cylinder, there being a possibility of picking: said tumblers through an application of picking torque tor the key plug, and means interposed between the longi-v tudinal keyway slot and said cylinder when the sleevev and key plug are in locking position, said interposed means being loosely held in position by said sleeve for' preventing application of tumbler picking torque to the sleeve by a tool inserted and manipulated through the keyway when said tool acts on said interposed means.

2. ln a combination of the class described, a lock cylinder, a sleeve rotatable in a bore of said cylinder, means on said sleeve for operating a lock when said sleeve is rotated, a key plug rotatable in said sleeve and having a longitudinal keyway terminating in a longitudinal slot on the outer surface of the key plug, a series of tumblers controlling the rotation of said key plug relaf tively to a locking position in said sleeve and the rotation of said sleeve relatively to a locking position in the bore of said cylinder, there being a possibility of picking said vtumblers through an application of picking torque to the: .key plug, said sleeve having a slot wider than said keyway slot, the longitudinal centers of said slots being substan tially aligned in the locking position of said key plug and. sleeve, and a guard assembled between the key plug and the surface of the cylinder bore, said guard being loosely held within said sleeve slot and substantially closing the'- longitudinal slot of the keyway, for preventing applicationl of tumbler picking torque to the sleeve by a tool inserted and manipulated through the keyway when said tool actsI on said guard.

3. ln a combination of the class described, a lock' cylinder, a sleeve rotatable in a bore of said cylinder, means on said sleeve for operating a lock when said sleeve is rotated, a key plug rotatable in said sleeve and having a longitudinal keyway terminating in a longitudinal slot on the outer surface of the key plug, a series of tumblers controlling the rotation of said key plug relatively to a locking position in said sleeve and the rotation of said sleeve relatively to a locking position in the bore of said cylinder, there being a possibility of picking said tumblers through an application of picking torque to the key plug, said sleeve having a slot wider than said keyway slot, the longitudinal centers of said slots being substantially aligned in the locking position of said key plug and sleeve, a guard assembled between the key plug and the surface of the cylinder bore, said guard being loosely held within said sleeve slot and substantially closing the longitudinal slot of the keyway, for preventing application of tumbler picking torque to the sleeve by a tool inserted and manipulated through the keyway when said tool acts on said guard, and detent means yieldingly resisting rotation of said sleeve relatively to its locking position in said cylinder,

4. ln a combination of the class described, a lock cylinder, a sleeve rotatable in a bore of said cylinder, means on said sleeve for operating a lock when said sleeve is rotated, a key plug rotatable in said sleeve and having a longitudinal keyway terminating in a longitudinal slot on the outer surface of the key plug, a series of tumblers` controlling the rotation of said key plug relatively to a locking position in said sleeve and the rotation of said sleeve relatively to a locking position in the bore of said cylinder, there being a possibility of picking said tumblers through an application of picking torque to the key plug, means interposed between the longitudinal keyway slot and said cylinder when the sleeve and key plug are in locking position, said interposed means being loosely held in position by said sleeve for preventing application of tumbler picking torque to the sleeve by a tool inserted and manipulated through the keyway when said tool acts onsaid interposed means, and detent means yieldingly resisting rotation of said sleeve relatively to its locking position in said cylinder.

when the sleeve and key plug are in locking position, said.

interposed means being loosely held in position by said sleeve for preventing application of torque to the sleeve relatively to said cylinder by a tool inserted and manipulated through the keyway when said tool acts on said interposed means.

6. In a combination of the class described, a lock cylinder, a sleeve rotatable in a bore of said cylinder, means on said sleeve for -operating a lock when said sleeve is rotated, a key plug rotatable in said sleeve and having a longitudinal keyway terminating in a longitudinal slot on the outer surface of the key plug, a series of tumblers controlling the rotation of said key plug relatively to a locking position in said sleeve and the rotation of said sleeve relatively to a locking position in the bore of said cylinder, there ibeing a possibility of picking said tumblers through an application of picking torque to the key plug, said sleeve having a slot wider than said keyway slot, the longitudinal centers of said slots being substantially aligned in the locking position of said key plug and sleeve, a guard assembled in position between the key plug and the surface of the cylinder bore, said guard being loosely held within said sleeve slot and substantially closing the longitudinal slot of the keyway, for preventing application of tumbler picking torque to the sleeve by a tool inserted and manipulated through the keyway when said tool acts on said guard, and detent means yieldingly resisting rotation of said sleeve relatively to its locking position in said cylinder.

References Cited by the Examiner UNITED STATES PATENTS 1,261,089 4/1918 Yawman 70-372 X 1,417,132 5/1922 Barker 70-364 1,989,327 1/1935 Machinist 70364 2,111,098 3/1938 Segal 70-378 X 2,596,720 5/1952 Pastor et al 70-364 2,682,764 7/ 1954 Kotab 70-392 X 2,977,786 4/ 1961 Kendrick et al 70-373 X FOREIGN PATENTS 1,154,732 9/1963 Germany.

718,451 11/ 1954 Great Britain.

MARVIN A. CHAMPION, Primary Examiner. P. TEITELBAUM, Assistant Examiner.

Claims (1)

1. IN A COMBINATION OF THE CLASS DESCRIBED, A LOCK CYLINDER, A SLEEVE ROTATABLE IN A BORE OF SAID CYLINDER, MEANS ON SAID SLEEVE FOR OPERATING A LOCK WHEN SAID SLEEVE IS ROTATED, A KEY PLUG ROTATABLE IN SAID SLEEVE AND HAVING A LONGITUDINAL KEYWAY TERMINATING IN A LONGITUDINAL SLOT ON THE OUTER SURFACE OF THE KEY PLUG, A SERIES OF TUMBLERS CONTROLLING THE ROTATION OF SAID KEY PLUG RELATIVELY TO A LOCKING POSITION IN SAID SLEEVE AND THE ROTATION OF SAID SLEEVE RELATIVELY TO A LOCKING POSITION IN THE BORE OF SAID CYLINDER, THERE BEING A POSSIBILITY OF PICKING AND TUMBLERS THROUGH AN APPLICATION OF PICKING TORQUE TO THE KEY PLUG, AND MEANS INTERPOSED BETWEEN THE LONGITUDINAL KEYWAY SLOT AND SAID CYLINDER WHEN THE SLEEVE AND KEY PLUG ARE IN LOCKING POSITION, SAID INTERPOSED MEANS BEING LOOSELY HELD IN POSITION BY SAID SLEEVE FOR PREVENTING APPLICATION OF TUMBLER PICKING TORQUE TO THE SLEEVE BY A TOOL INSERTED AND MANIPULATED THROUGH THE KEYWAY WHEN SAID TOOL ACTS ON SAID INTERPOSED MEANS.

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