Lock cylinder with plate tumblers

Abstract: A lock cylinder has resilient plate tumblers (8) which are arranged in the rotatable cylinder core (1) and project beyond the rotary joint (F) between the cylinder core (1) and the cylinder housing (3) into chambers (10) of the cylinder housing (3) in the checking position of the cylinder core (1). For achieving release of the cylinder core (1) for rotation thereof, the tumblers (8) may be set by indentations (7) of the key (6) into a position in which the plate tumblers (8) no longer protrude beyond the rotary joint (F). Removal of the key is checked when the key (6) has been turned, by axial shifting of the cylinder core (1) in the cylinder housing (3) such that the end face (19) of at least one plate tumbler (8) passes below a chamber wall (20) of the cylinder housing (3) blocking displacement of the plate tumbler (8) beyond the rotary joint (F).

Description: The present invention relates to a lock cylinder with resilient plate tumblers which are arranged in the rotatable cylinder core, project beyond the rotary joint between the cylinder core and the cylinder housing into chambers of the cylinder housing in the checking position of the cylinder core and, for achieving release of the cylinder core for rotation thereof, may be set by indentations of the key into a position in which the plate tumblers no longer protrude beyond the rotary joint. Lock cylinders of this type allow the key to be removed after only 180 º rotation, as the locking heads of the plate tumblers are then able to advance in the opposite direction beyond the rotary joint into an escape space of the cylinder housing aligned with the chambers and the tails into the chambers. Lock cylinders of this type may not be used in cases where it is desirable for the ward or the like of the cylinder core to pass through a greater rotational angle range without intermediate removal. If the closing cam or the like were adapted to continue rotating beyond 180 º , the user would become irritated or complete expulsion of a locking element would only half occur in a virtually unnoticed manner if the user were able to remove the key in the 180 º position, for which the key generally has to be grasped. There exist other locking mechanisms which necessitate a complete rotation of the cylinder core round 360 º . It is an object of the present invention to provide lock cylinder of this type which is simple to produce, without increasing the number of parts, such that the key can however be inserted and removed only in the 0 º position, and the 360 º which is identical thereto after rotation of the cylinder core. A more versatile lock cylinder of the type described is achieved as a result of such a design. The complete rotation exceeding 360° of the cylinder core may be achieved without intermediate removal while maintaining the basic principle and without increasing the number of parts. An additional advantage is that damage due to improper handling, which might otherwise easily occur, is avoided in that the user can easily superimpose a rotational movement on the axial pulling movement in the region of the 180° rotational position with his operating hand as he grasps the key in the normal manner and this often caused jamming of the plate tumblers. The desired aim is achieved simply by checking, which comes into effect when the key has been turned, of removal of the key by axial shifting of the cylinder core in the cylinder housing such that the end face of at least one plate tumbler passes below a chamber wall of the cylinder housing blocking displacement of the plate tumbler beyond the rotary joint. A lock cylinder of this type, and according to the pre-characterising portion of claim 1, is known from EP-A-0 234 144. The invention provides for a lock cylinder according to the pre-characterising portion of claim 1, characterised in that there is positive cam control between the cylinder core and cylinder housing which produces the axial shifting of the cylinder core when the cylinder core is rotated. Because of the blocking action of said plate tumbler, the key remains trapped until it again reaches its insertion position with respect to the cylinder core, this only being the case after passing through the entire 360°. As the cylinder core is mounted in a bore in the cylinder housing, the guidance which can be used most desirably for the axial shifting is achieved at the same time. For the shifting action, either the cylinder core is somewhat longer in design or the cylinder housing is somewhat shorter in design in order to achieve the axially oriented offset of the end face of the plate tumbler relative to the mating chamber. Blocking which is optimally distributed in terms of stress takes place when all plate tumblers are below a respective chamber wall, in other words are offset from the cross-sectional plane of the chambers, in the axial shift position. Positive cam control of the axial shifting of the cylinder core results in a completely foolproof mode of operation; the operator does not have to observe any preconditions, for example, by pressing the lock cylinder against a contact face, as for example in the prior art of EP-A-0 234 144 and FR-A-2 325 786. This design is optimised in that positive cam control exists in both displacement directions. This is achieved in a constructionally advantageous manner in that one displacement cam is arranged at the rear end of the cylinder core and co-operates with an opposing cam on the rear face of the cylinder housing and a second displacement cam is located at the front end of the cylinder core and co-operates with an opposing cam in the front face of the cylinder housing. Corresponding cams and opposing cams may easily be produced with the desired precision by injection moulding. It has also proven advantageous for the displacement cams to be mutually offset by an angle of about 90º and for the opposing cams to have a control face extending over about 180º in each case. It is also proposed that the displacement cam acting on the rear end issue from a closing cam member connected to the cylinder core and that a rotationally entraining portion of the displacement cam engage in a rotationally entraining recess in the cylinder core. This displacement cam therefore has an additional function. To optimise the corresponding entrainment coupling between the rotationally entraining member and the lock cylinder, it is finally proposed that the rotationally entraining portion of said displacement cam be opposed by a second diametrally opposed rotationally entraining cam of the closing cam member which projects into a matching, somewhat wider, rotationally entraining recess in the cylinder core. Lastly, it has proven advantageous with respect to complete utilisation of the rotational angle achieved, if the closing cam member is a gear wheel. The gear wheel can step down or step up and transmit the rotational movement via further gear wheel or can co-operate directly with a rack-like locking bolt. An embodiment of the invention will now be described in detail with reference to the accompanying drawings, in which Figure 1 is a side view of an embodiment of the lock cylinder according to the invention in which the cylinder core is in the zero position with the key aligned for insertion (shown in the insertion position in dot-dash lines); Figure 2 is a side view where the key is inserted and is located in the 180 º position, in which position removal of the inserted key by simultaneous axial shifting of the cylinder core is prevented; Figure 3 shows a first displacement cam resting on a closing cam member, for the rear end of the lock cylinder; Figure 4 shows the associated opposing cam on the rear face of the cylinder housing; Figure 5 shows a view toward the second displacement cam in the region of the front end of the cylinder core; Figure 6 shows the corresponding opposing cam at the front face of the cylinder housing, the cylinder housing being shown individually; Figure 7 is a plan view of Figure 5; Figure 8 is a section along line VIII-VIII in Figure 6; Figure 9 is a vertical section through the lock cylinder in the position according to Figure 1, with the key inserted and in the zero position; Figure 10 is a similar section showing the situation according to Figure 2 on an enlarged scale, that is after a rotation of the cylinder core through 180 º , in which position the key is blocked against removal by the axial shifting of the cylinder core; Figure 11 is a section along line XI-XI of Figure 9 and Figure 12 is a section along line XII-XII of Figure 10. The lock cylinder illustrated comprises a rotatable cylinder core 1. This is mounted in a longitudinally directed bore 2. The bore 2 is located in the upper half of a cylinder housing 3, having an oval cross section. The cylinder core 1 has a longitudinally directed key channel 4. This key channel 4 is adapted to the profile of the shank 5 of a key 6. The key is a flat key which is provided, on one narrow side, with successive indentations 7, the so-called key wards. The bottoms of the indentations 7 are at different heights. The key 6 co-operates with plate tumblers 8. The plate tumblers 8 are guided in a respective transverse duct 9 of the cylinder core 1 intersecting the key channel 4. Five such transverse ducts 9 are produced in succession at equal intervals in the cylinder core 1. The plate tumblers 8 resemble window frames for the passage of the shank 5. When the key 6 has been inserted, the plate tumblers 8 are adjusted or set such that their heads 8' and their tails 8'' are aligned with a rotary joint F between cylinder core 1 and cylinder housing 3. The rotary joint F is defined by the bore 2. Allowing for the vertical movement of the plate tumblers 8 taking place in the longer axis of the cylinder housing 3 which is oval in cross section, a respective chamber 10 is located in front of the head 8', at the top of Figure 11, of each plate tumbler 8. When the key 6 has been removed, the heads 8' of the plate tumblers engage therein in a rotationally locking manner. They are held therein, projecting beyond the joint, by compression springs 11 permanently loading the plate tumblers in the direction of the arrow x . The compression springs 11 rest on a base 12 of a spring chamber 13 as a fixed abutment, the spring chamber being arranged parallel to the direction of movement of the plate tumblers 8 and formed by a bore. This spring chamber 13 also located in the cylinder core laterally penetrates the transverse duct 9. Consequently, a lateral nose 14 of the plate tumbler 8 projecting into the cross section of the spring chamber can form the other movable abutment of the compression spring 11. The chambers 10 designed in the manner of longitudinal ducts in the cylinder housing 3 are diametrally opposed by an escape space 15 extending into the lower half of the cylinder housing 3 which is oval in cross section. The escape space 15 extends almost over the entire length of the cylinder housing 3 and allows the closure-induced escape of the plate tumblers 8 in the opposite direction to the chamber 10. This escape takes place when teeth or projections 16 of the shank 5 located between the indentations 7 ride over the corresponding window edge 17 of the plate tumblers 8. When the key 6 has been inserted, the cylinder core 1 may be rotated due to the adjustment of the plate tumblers 8 into a position in which they no longer project beyond the rotary joint F. Head 8' and tail 8'' or their end faces 18 and 19 follow the external curvature of the cylinder core 1, utilising the cylindrical cross section of the cylinder core 1 to a maximum. The key 6 would normally be removable after a 180 º . rotation with the construction described. This is prevented, by checking of the key removal which comes into effect immediately after the key 6 has been rotated from the zero position. This is achieved by a controlled axial shift of the cylinder core 1 guided in the bore 2. The corresponding axial shift in the cylinder housing 3 causes the end face 19 of at least one plate tumbler 8 to pass below a laterally located chamber wall 20, virtually against a portion of the bore 2 of the cylinder housing 3. Displacement of this plate tumbler 8 beyond the rotary joint F is therefore understandably blocked. The axial shifting takes place to an extent corresponding to substantially half the centre distance Y between chambers 10 located in succession at equal intervals. The shift stroke of the cylinder core 1 is designated by y' as can be seen in Figure 10. As shown by comparison of Figures 11 and 12, the plate tumbler 8 with its end remote from the otherwise checking head 8' passes transversely or radially outwardly toward the chamber wall 20, i.e. with the tail 8'' or the associated end face 19. In the embodiment illustrated, all five plate tumblers 8 are used for achieving the described blocking effect; therefore,they each pass below an associated chamber wall 20. The axial shifting is based on positive control of the cylinder core 1, more precisely positive cam control. This positive cam control causes the cylinder core 1 to be positively controlled in both displacement directions, superimposed on the rotation thereof. Therefore, the user does not himself have to press or pull the cylinder core 1 in one or other direction. In practice, a displacement cam N1 is located in the region of the rear end of the cylinder core 1, on the left in the drawing, and co-operates there with an opposing cam G1 on the corresponding rear face 3' of the cylinder core housing 3. This displacement cam N1 rests on the face of the rim 21' of a closing cam member 21 connected to the cylinder core 1. The closing cam member is produced in the form of a gear wheel and is connected, in particular fixed by a cotter, to an offset peg 22 of the cylinder core 1. The corresponding transverse cotter is identified by reference numeral 23. Instead of a transverse cotter connection, an axially orientated screw connection, illustrated in dot dash lines in Figure 9, may also be used since the peg 22 has an internal thread into which the screw bolt of a retaining screw overlapping the rear of the gear wheel engages. The opposing cam G1 is achieved by a stepped design of the rear face 3' of the cylinder housing 3. If the plate tumblers 8 are properly orientated relative to the chambers 10, in terms of escape, the displacement cam N1 rests on the raised portion a of the opposing cam G1, which raised portion a passes into the undercut or deeper portion c on both sides via falling ramps b. The height difference z is shown in Figure 9 and is a good 1.5 mm. The height difference corresponds to the height, measured in the axial direction, of the displacement cam N1 to the rim 21', or the axial shift stroke y' . The remaining means of the positive cam control are produced in the front face 3'' of the cylinder housing 3. The associated displacement cam is identified by reference numeral N2. It rests in the back of a flange 24 of the cylinder core 1. This flange 24 projecting beyond the cross section of the cylinder core 1 passes into an annular step 25 (cf. Figure 7) which rests in a rotationally and displaceably guided manner in a correspondingly dimensioned hollow 26 (cf. Figure 8) in the front face 3'' of the cylinder housing 3. The second displacement cam N2 follows the annular step 25, pointing in the direction of the closing cam member 21. The corresponding second opposing cam G2 formed in the front face 3'' of the cylinder housing 3 is also produced here simply by the design of different height portions of the hollow 26. A raised portion again designated by a is thus produced, which passes into the lower portion c via two ramps b falling in both directions of rotation as can be seen from Figures 6 and 8. In the rotational position in which the first displacement cam N1 passes on the associated opposing cam G1 toward the raised portion a, the second displacement cam N2 located at the other end of the lock cylinder 1 rests on the lower portion c of the opposing cam G2. This is achieved constructionally in that the displacement cams N1 and N2 are mutually offset by an angle of about 90 º and the opposing cams G1 and G2 form a control face extending over 180 º in each case. An equivalent negative/positive control profile is therefore provided. The displacement cam N1 at the rear end of the lock cylinder fulfils a more far reaching function with respect to rotation prevention between lock cylinder member 21 and cylinder core 1, which is more specifically preferably applicable in the case of prevention by the screw illustrated in Figure 9 and axially engaging in a threaded bore of the offset peg 22. The displacement cam N1 does in fact continue there, in a radially orientated manner, into the cross sectional region of the cylinder core 1. It engages via a rotationally entraining portion 27 in a mating rotationally entraining recess 28 of the offset annular step 29 between cylinder core 1 and peg 22. In order to optimise this arrangement further in the absence of a transverse cotter 23, the rotationally entraining portion 27 of the displacement cam N1 is allocated a second diametrally opposed rotationally entraining cam 30. This shaped additional cam 30 which is also identical to the end of the closing cam member 21 enters a matching rotationally entraining recess 31 which is somewhat wider than the corresponding width of the other rotationally entraining recess 28. The difference in width is shown particularly clearly in Figure 7. The second rotationally entraining cam 30 is illustrated in broken lines. The difference in width ensures the correct engagement of this "claw coupling". The mode of operation is briefly as follows: The key 6 may be introduced and removed in the zero position in Figures 1 and 9. In this position, the plate tumblers 8 may escape into the congruent chambers 10 or into the continuous groove-like escape space 15. If the key is now rotated through 180 º , for example in an anticlockwise direction, axial shifting of the cylinder core 1 in the direction of the arrow A, i.e. to the right with respect to the drawing, begins, with positive control, immediately this rotational movement begins. The plate tumblers 8 therefore lose the opportunity for free escape. They have passed, with their end face 19 formed at the tail 8'', against non-compartmental portions of the bore wall of the cylinder housing 3. They are therefore located in front of the described chamber walls 20. This escape movement which is possible in the prior art is therefore checked. In order, for example, to be able to perform the entire locking stroke, the cylinder core 1 may now be rotated without interruption and without intermediate removal by means of the key 6 by a further amount of 180 º so that a complete rotational angle of 360 º is eventually achieved without removal of the key. The key 6 may then be removed in the regained starting position.

Claims: Lock cylinder with resiliently-biased plate tumblers (8) which are arranged in the rotatable cylinder core (1), project beyond the rotary joint (F) between cylinder core (1) and cylinder housing (3) into chambers (10) of the cylinder housing (3) in the checking position of the cylinder core (1) and, for achieving release of the cylinder core (1) for rotation thereof, may be set by indentations (7) of the key (6) into a position in which the plate tumblers (8) no longer protrude beyond the rotary joint (F), wherein removal of the key is checked which comes into effect once the key (6) has been turned beyond the checking position, by axial shifting of the cylinder core (1) in the cylinder housing (3) such that the end face (19) of at least one plate tumbler (8) passes below a chamber wall (20) of the cylinder housing (3) blocking displacement of the plate tumbler (8) beyond the rotary joint (F), characterised in that there is positive cam control between the cylinder core and cylinder housing which produces the axial shifting of the cylinder core (1) when the cylinder core is rotated. A lock cylinder according to claim 1, characterised in that all of the plate tumblers (8) are located under a respective chamber wall (20) in the axial shift position. A lock cylinder according to claim 1 characterised in that the positive cam control exists in both directions of displacement. A lock cylinder according to one or more of the preceding claims, characterised in that a first displacement cam (N1) is arranged at the rear end of the cylinder core (1) and co-operates with a first opposing cam (G1) on the rear face (3') of the cylinder housing (3) and a second displacement cam (N2) is located at the front end of the cylinder core (1) and co-operates with a second opposing cam (G2) in the front face (3") of the cylinder housing (3). A lock cylinder according to claim 4 characterised in that the displacement cams (N1 and N2) are mutually offset by an angle of about 90º and the opposing cams (G1 and G2) have a control face extending over about 180º. A lock cylinder according to claim 4 or claim 5 characterised in that the displacement cam (N1) issues from a closing cam member (21) connected to the cylinder core (1), and a rotationally entraining portion (27) of the displacement cam (N1) engages in a rotationally entraining recess (28) of the cylinder core (1). A lock cylinder according to claim 6 characterised in that the rotationally entraining portion (27) of the displacement cam (N1) is opposed by a second diametrally opposed rotationally entraining cam (30) of the closing cam member (21) which projects into a matching, somewhat wider rotationally entraining recess (31) in the cylinder core. A lock cylinder according to one or more of the preceding claims, characterised in that the closing cam member (21) is a gear wheel.

Inventors: HAEUSER HERBERT PHILIPP, HAEUSER, HERBERT PHILIPP, Häuser, Herbert Philipp
Applicants: DOM SICHERHEITSTECHNIK, DOM-SICHERHEITSTECHNIK GMBH & CO. KG
Application year: 1993
Main classification: E05B29
IPC codes: E05B29