GB2144480A

GB2144480A - Combination lock

Info

Publication number: GB2144480A
Application number: GB08321193A
Authority: GB
Inventors: Hing Hyuan Yeh
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-08-05
Filing date: 1983-08-05
Publication date: 1985-03-06
Also published as: GB8321193D0

Abstract

The lock comprises a casing (1, 10) slidably mounting a detent (58) attached to which is an actuating button (6) and a control rod (3, 4) which extends through relatively rotatable rings (2). Ball bearings (7) are engaged between the rings and the rod and peripheral grooves (34) in the rod are engaged by the bearings to prevent axial movement of the rod and hold the lock closed. When the bearings are aligned with an axial slot (31) in the rod, the rod can be moved and permits movement of the actuating button to open the lock. A projection (101) on the casing engages a recess (65) of the actuating button, but the latter is raisable out of engagement to permits its rotation. A spigot (63) of the button is guided in an arcuate slot (42) in the rod so that the latter is moved axially, on rotation of the button, to take the ball bearings out of engagement with the rings. The rings can, therefore, be rotated without the bearings to change the combination. <IMAGE>

Description

SPECIFICATION Novel combination lock The present invention relates to a novel combination lock and in particular to one mainly comprising an actuating button, a surface plate, a mounting plate, a bolt, a slotted rod, three tumblers, a fixing frame and a casing characterized in that the combination numbers of the combination lock can randomly be changed for security.

The combination lock has been known in Europe since at least the sixteenth century, and its origin are lost. The bolt or shackle in a combination lock has slots in it. A number of tumblers are provided with numbers or letters around the outside and projections on the inside, which fit the slots. The tumblers must be lined up correctly in order for the shackle to be withdrawn. Most combination locks are designed so that the combination can be changed occasionally for security. However, changing the combination numbers of the combination locks is troublesome. Thus, the inventor of this invention designs a novel combination lock which is accurate and easily operated.

It is a primary object of the present invention to provide a novel combination lock of which the combination numbers can randomly be changed for security.

It is another object of the present invention to provide a novel combination lock the combination numbers of which may not be changed due to carelessness.

It is still another object of the present invention to provide a novel combination lock which is accurate and easily operated.

It is still another object of the present invention to provide a novel combination lock which is economic to produce.

Other objects and a fuller understanding of the present invention may be had by referring to the following detailed description taken in conjunction with the accompanying drawings, wherein: Figure 1 is a fragmentary perspective view of a combination lock of a preferred embodiment invention; Figure 2 is a top view of the combination lock according to the present invention; Figure 3 is a cross-sectional front view of the combination lock taken along line E-E of Fig. 2; Figure 4 is a front view of a bolt of the combination lock according to the present invention; Figure 5 is a top view of Fig. 4; Figure 6 is a bottom view of Fig. 4; Figure 7 is a side view of Fig. 4; Figure 8 is a front view of a fixing frame of the combination lock according to the present invention; Figure 9 is a top view of Fig. 8; Figure 10 is a sectional view taken along line D-D of Fig. 8;; Figure ii is a bottom view of an actuating button of the combination lock according to the present invention; Figure 12 is a top view of Fig. 11; Figure 13 is a side view of Fig. 11; Figure 14 is a sectional view taken along line C-C of Fig. 3; Figure 15 is a sectional view taken along line B-B of Fig. 3; and Figure 16 is a sectional view taken along line A-A of Fig. 3; Figure 1 7 is shows the way to insert a plastic film between the actuating button and the surface plate of the combination lock according to the present invention; Figure 18 is shows the way to rotate the actuating button of the combination lock according to the present invention.

Referring to the drawings and in particular to Fig. 1, Fig. 2 and Fig. 3 thereof, the combination lock according to the present invention comprises a slotted rod (4) which is provided with three grooves (41) and a curved slot (42). The slotted rod (4) is placed into a slot (31) of a bolt (3) which is provided with a hole (32) and three circular grooves (34). The composite of the bolt (3) and the slotted rod (4) is encased in three tumblers (2). Each of the tumblers (2) is provided with numbers (23) around the outside and protuberances (22) on the inside, which fit the slots (34) of the bolt (3). The tumblers (2) together with the bolt (3) and the slotted rod (4) are just mounted into a mounting plate (5). At one end of the mounting plate (5) is a projection (55) which engages with a spring (51), and at the other end of the mounting plate (5) is a tongue (58).A surface plate (1) having three rectangular holes (100), an opening (11) and a slot (200) is placed on the mounting plate (5) in such a way that each tumbler (2) is fitted into one rectangular hole (100). An actuating button (6) provided with a pin (61) and a groove (62) is mounted on the surface plate (1), with the pin (61) passing through the opening (11), the mounting plate (5) and the hole (32) of the bolt (3). The acutating button (6) is fixed by engaging its groove (62) with a washer (6). At the bottom of the pin (61) is an eccentric pin (63) which is inserted into the curved slot (42) of the slotted rod (4).

In the space between each groove (41) of the slotted rod (4) and a groove (21) of a corresponding tumbler (2) is placed a steel ball (7).

Under the tumblers (2) is a fixing frame (8) which is provided with six fins (9) each having a hook-like tip (82) (as shown in Fig. 8, 9 and 10). The hook-like tips (82) are used to engage with indentations (25) of the tumblers (2), so that the positions of the tumblers (2) may be fixed.

At the lowermost part of the combination lock is a casing (10).

When the combination lock according to the present invention is locked, the steel balls (7) are located between the grooves (21) of the tumblers (2) and circular grooves (34) of the bolt (3), thus preventing the bolt (3) from being withdrawn.

If it is desired to open the combination lock according to the present invention, it is necessary to dial the correct numbers of the combination lock first. When the correct numbers of the combination lock are dialed, the steel balls (7) will be located at the slot (31) of the bolt (3). Thus, the bolt (3) is then withdrawn by moving the actuating button (6). As a result, the mounting plate (5) is moved to the left and the combination lock is opened. At that time protuberance (69) of the actuating button (6) is no longer restrained by the opening (11) of the surface plate (1), but recess (65) of actuating button is restricted by the projection (101) of the casing (10). Consequently, the actuating button (6) may still not be rotated and the slotted rod (4) cannot be further withdrawn.In other words, the steel balls (7) remain in the positions between the slot (31) of the bolt (3) and plane surface (45) of the slotted rod (4). Thus the tumblers (2) cannot be rotated and the combination number of the combination lock cannot be changed.

To change the combination numbers of the combination lock, first turn the tumblers (2) to the positions where the steel balls (7) are moved to the slots (31) of the bolt (3). Then insert a specially designed plastic film (105) between the actuating button (6) and the surface plate (1) so as to lift the actuating button (6) to a position where the actuating button (6) will not be obstructed by the projection (101) of the casing (1), and push the actuating button (6) to the left (as shown in Fig. 1 7 and 18). Thus the bolt (3) and the mounting plate (5) is withdrawn and the combination lock is opened.Rotate the actuating button (6) through an angle 90 in the clockwise direction, thereby further withdrawing the slotted rod (4) to the position where the steel balls (7) are placed between inner surface (22) of the tumblers (2) and the groove (41) of the slotted rod (4); thus, the tumblers (2) can be freely rotated without carrying the steel balls (7). Consequently, the combination numbers of the combination lock can be changed. Further, the actuating button (6) can not be rotated with an angle less than 90 because the movement of protuberance (68) of the actuating button (6) is limited by slot (33) of the bolt (3).

In addition, by means of a spring (51), the mounting plate (5) can be moved backward and then sprung back when the actuating button (6) is not actuated, so that the tum blers (2) may be turned immediately after the combination lock is opened and it is unneces sary to line up again the correct numbers in order to lock the combination lock; thus, the duration of exposing the numbers is much decreased. In short, the safety of the combination lock is increased.

Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure has been made by way of example only and that numerous changes in the detail of construction and the combination and arrangement of parts may be resorted to without departing from the scope and spirit of the invention as hereinafter claimed.

Claims

1. An improved combination lock comprising: a casing; a fixing frame placed into casing, said fixing frame being provided with six fins each having a hook-like tip; a slotted rod provided with three groove and a curved slot; a bolt having a slot into which is mounted said slotted rod, said bolt being provided with a hole and three circular slots; three tumblers encasing said slotted rod and said bolt, the internal of each said tumbler being provided with a plurality of grooves; a mounting plate served to accomodate said slotted rod, said bolt and said tumblers, said mounting plate having a projection on which is mounted a spring; an actuating button mounted on said covering plate, said actuating button being provided with a pin which is inserted into said hole of said bolt; and a surface plate mounted on the top of said mounting plate, said surface plate being provided with three holes for mounting said three tumblers and an opening for mounting said actuating button.

2. A combination lock comprising a casing, a detent movable between operative and inoperative positions, an actuating member for moving the detent, a plurality of rotatable rings carrying combination markings, a control member extending axially within the rings and movable with the actuating member, engag ing means between the rings and the control member and movable with the rings and preventing axial movement of the control member unless the engaging means are all in alignment in a predetermined angular position relative to the control member, and releasable means releasable to permit further movement of the actuating member to cause the control member to move said engaging means out of engagement with the rings, whereby the rings can be moved relative to the engagement means to change the combination.

3. A combination lock substantially as herein described with reference to the accom panying drawings.