GB2210922A - Cylinder lock - Google Patents

Abstract

The lock is operable by key 5 having an arch-shaped shank 54. The lock includes a stationary case 1, a rotatable cylinder 2, and a rotatable core 3. The rotatable core 3 has an integral head 33, formed helically at the front tip of a rod member 32 and engageable with supports 56 at the sides of a helical notch 53 on key 5. The rotatable core 3 is installed in the rotatable cylinder 2 with both of its ends welded to the rotatable cylinder 2 to define an arch-shaped keyway 34. Semispherical recesses 23 are spaced lengthwise along cylinder 2 for partial reception of pin-tumblers 26 and driving pin tumblers 14 are arranged in holes 13 in the stationary case 1. A steel ball retainer 24 is set in line with recesses 23 and the steel ball 25 acts as a bearing to facilitate turning movement of cylinder 2 with respect to case 1. The key 5 has a hollow tube 52 welded to grip 51 and formed with helical notch 53 and the arch shaped shank 54 has semispherical slots 55 on its concave surface to lift pin-tumblers 26. To unlock the lock, key 5 is inserted into keyway 34 with its concave surface facing downwards and the key is turned in a helical manner. <IMAGE>

Description

CYLINDER LOCK The present application relates to locks, and more particularly, to cylinder locks equipped with antipick mechanisms.

Pin-tumbler lock cylinders are used to a great extent in door locks, night latches, padlocks and many other types of locking devices, but those cylinders now in general use suffer the common disadvantage of being capable of being unlocked by a pass key or lock pick.

Accordingly, many locks such as magnetic locks, computerized locking systems, etc., exist in the prior art for a more secure locking purpose. However, most of these devices are quite complicated and difficult to manufacture and use.

The present invention is therefore intended to provide a cylinder lock equipped with an antipick mechanism.

The present invention is still intended to provide a cylinder lock which assures a higher level of protection on doors.

The present invention is further intended to provide a cylinder lock having pin tumblers located at a place remote from the keyway.

The present invention is still intended to provide a cylinder lock having a rotatable core which defines a keyway having no direct contact with the pintumblers.

The features of the present invention would become apparent after a careful reading of the detailed description provided hereinafter, with appropriate reference to the attached drawings.

In the drawings: FIG. 1 is an exploded view of a cylinder lock and a key constructed in accordance with the present invention; FIG. 2 is a front elevational view of the cylinder lock shown in FIG. 1; FIG. 3 is a perspective view of a key constructed in accordance with the present invention; FIG. 4 is a longitudinal vertical sectional view of the cylinder lock, illustrating the locked state; and FIG. 5 is a view similar to FIG. 4, but illustrating the unlocked state.

Referring to the drawings and initlally to FIG. 1, it can be seen that the cylinder lock constructed in accordance with the present invention comprises a stationary case 1, a rotatable cylinder 2, a rotatable core 3 and an additional spacer 4.

Referring to FIGS. 1 and 2, reference numeral 1 designates a stationary case provided with a bore 11 extending lengthwise therethrough below its center axis, for the reception of a rotatable cylinder 2. The outer end of the cylindrical bore 11 is provided with a circumferential lip 12. A longitudinally extending row of holes 13 extends radially from the cylindrical bore 11 to the surface of the stationary case 1. Four holes 13 are shown in the drawings; however, this number is not critical and any number and arrangement of holes may be used if desired.

The rotatable cylinder 2 is provided with a cylindrical bore 21 extending lengthwise for the reception of a rotatable core 3 and is provided at its rear with a conventional bolt actuating member (not shown). The rotatable cylinder 2 has an abutment flange 22 at the front side thereof to prevent inward axial movement thereof with respect to the stationary case 1. A series of radially disposed semispherical recesses 23 are spaced lengthwise along the rotatable cylinder 2, for partial reception of the reciprocating pin-tumblers 26. A steel ball retainer 24 is set in line with the row of semispherical recesses 23, for partial reception of a steel ball 25. The steel ball 25 communicates with the longer coil spring 16 and acts as a bearing to facilitate the turning movement of the cylinder 2 with respect to the stationary case 1.The number of the recesses, 23 and 24, is not critical, so far if the total number thereof is equal to the number of holes 13 of the stationary case 1. When the rotatable cylinder 2 is retained inside the stationary case 1, the flange 21 stops at the circumferential lip 12 and the four holes 14 of the stationary case 1 set in alignment with the three recesses 23 and the steel ball retainer 24 of the cylinder 2.

The reciprocating pin-tumblers 26 cooperate with driving pin-tumblers 14 arranged in a series of holes 13 disposed in a line extending lengthwise along the surface of the stationary case 1. The driving pintumblers 14 are urged toward the cylinder 2 by means of respective coil springs 15, positioned in the holes 13.

The reciprocating pin-tumblers 26 together with the driving pin-tumblers 14 serve to control the turning combination of the rotatable cylinder 2 with respect to the stationary case 1.

The rotatable core 3 includes a cylindrical plug 31 and a cylindrical rod members 32. The plug 31 is of larger diameter and shorter length. The rod member 32 is of smaller diameter and longer length and has substantially an equal length as that of the rotatable cylinder 2 or the stationary case 1. The rod member 32 has a head 33 integrally formed at the front tip thereof. From the front, the head 33 has a substantially shell shape, as can best be seen in FIG.

2, and is formed helically from the rod member 32, the the thickness of the head 33 grows thinner and thinner from one side to another. After installation in the cylinder 2, the rotatable core 3 is welded at both ends to the cylinder 2. After installation in the case 1, the welded elements will define an arched-shaped keyway 34 (see FIG. 2) for the reception of a key 5 in accordance with the present invention as described more fully hereinafter.

The additional spacer 4, as depicted in FIG. 1, is attached to the rear end of the stationary case 1 and rotatable cylinder 2 and is provided with an opening 41 below its center for the plug 31 to pass through.

A preferable embodiment shows a key 5 including a grip 51 of flat plate form or any suitable form, a hollow tube 52 welded to said grip 51, a helical notch 53 formed on said hollow tube 52, and a shank 54 adjoins the hollow tube 52. The shank 54 is substantially an arched-shaped plate which comprises a row of semispherical slots 55 of different depth extending lengthwise on its concave surface. The intersection of the hollow tube 52 and the helical notch 53 is provided with a flat support 56 at both sides thereof.The number and arrangement of the semispherical slot 55 and the configuration of the shank 54 are not critical as long as the number of the semispherical slots 55 equal to the number of semispherical recesses 23 of the cylinder 2, the arrangement thereof matches each other and the configuration of the shank 54 matches the keyway 34 defined by the rotatable cylinder 2 and the rotatable core 3.

Referring now to FIG. 5, it will be noted that with the key 5 out of the keyway 34, driving pintumblers 14 normally extend across the junction between the periphery of the rotatable cylinder 2 and the surface of the bore 11 of the stationary case 1, so that the rotatable cylinder 2 cannot be turned.

When it is desired to unlock the cylinder lock, the key 5 is inserted into the keyway 34, as depicted most clearly in FIG. 6. The key 5 is initially inserted into the keyway 34 with the concave face of its shank 55 facing downwards. When the shank 55 inserts, to certain extent, into the keyway 34, the key 5 has to be turned in a helical manner such that the key shank 54 is fully inserted into the keyway 34 and at the same time is turned to the contact face of the reciprocating pin-tumblers 26. The supports 56 of the key 5 are then in engagement with the head 33 of the rotatable core 3. The key shank 54 having semispherical slots 55 of independent predetermined depth thereon will lift the corresponding pin-tumblers 26 into a position of exactly the same level as that of the junction of the periphery of the rotatable core 2 and the surface of the bore 11 of the stationary case 1 to allow the rotatable cylinder 2 to be turned by the key 5 for actuating the bolt-operating member (not shown).

While the invention has been explained in relation to its preferred embodiment, it will be obvious that by varying the lengths of the pin-tumblers 26, or the profile of the head 33 of the rotatable core 3 and changing the profiles of the key 5 accordingly, various embodiments may be obtained. Therefore, it is to be understood that the invention disclosed herein is intended to cover such alterations as fall within the scope of the appended claims.

Claims (9)

1. A cylinder lock comprising: a stationary case having a cylindrical bore extending lengthwise therethrough below a center axis thereof for reception of a rotatable cylinder, and a longitudinally extending row of holes extending radially from said cylindrical bore to a periphery of said stationary case; a rotatable cylinder having a cylindrical bore extending lengthwise therethrough for reception of a rotatable core, a series of radially disposed semispherical recesses extending lengthwise for partial reception of reciprocating pin-tumblers, and a steel ball retainer for partical reception of a steel ball; said reciprocating pin-tumblers cooperating with respective spring-loaded driving pin-tumblers arranged in said series of holes of said stationary case; a rotatable core having a plug and a rod member, said rod member being welded at both ends thereof to said rotatable cylinder and having an integrally formed head at the front tip thereof, said head defining an arch-shaped keyway remote from said reciprocating pin-tumblers after being combined with said cylinder; a key including a grip, a hollow tube welded to said grip, a helical notch formed on said hollow tube, and an arch-shaped shank adjoining said hollow tube; said shank being provided with a row of semispherical slots of depth corresponding to the length of said reciprocating pin-tumblers extending lengthwise on a concave surface thereof.

2. The cylinder lock according to claim 1, wherein said stationary case has a circumferential lip at an outer end of the bore thereof.

3. The cylinder lock according to claim 1, wherein said rotatable cylinder has an abutment flange at a front side thereof.

4. The cylinder lock according to claim 1, wherein said spring-loaded steel ball retained in said ball retainer of said rotatable cylinder acts as a bearing.

5. The cylinder lock according to claim 1, wherein said driving pin-tumblers are urged toward said rotatable cylinder by means of respective coil springs that positioned in the holes of said stationary case.

6. The cylinder lock according to claim 1, wherein said head of said rotatable core is substantially shell shape when viewed from the front side.

7. The cylinder lock according to claim 1, further comprising an additional spacer attached to a rear end of said stationary case and said rotatable cylinder.

8. The cylinder lock according to claim 7, wherein said additional spacer comprises an opening for said plug of said rotatable core to pass through.

9. The cylinder lock substantially as herein described with reference to and as shown in the accompanying drawings.