Locking device

[57] ABSTRACT

A locking device for locking a drawer of a table, a door in furniture, or the like. A housing is provided which has a longitudinal hole and a transverse bore connected with the lower portion of the longitudinal hole. A male member is slidably inserted in the longitudinal hole with a spring inwardly biasing the male member. The hole can extend on the other side of the bore and a second male member and spring can be provided therein. A sliding member is slidably housed in the transverse bore and is engaged with said male member or members in a manner such that when the sliding member is pushed in the outer portion of the male member or members are caused to project from the opening of the longitudinal hole against the pressure of the spring or springs in an engaged position, and when the sliding member is withdrawn the male member or members are automatically moved in a disengaged position by the pressure of the spring. A key is provided for pushing and withdrawing the sliding member.

Claims, 11 Drawing Figures

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PATENTED FEB 191974

3,792,884

SHEET 1 OF 3

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FIG.8

INVENTOR

ZENJI TUTIKAWA

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ATTORNEYS

PATENTED FEB 191974

3.792,884

SHEET 2 OF 3

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BY

ATTORNEYS

PATENTED FEB 191974

SHEET 3 OF 3

3,792,884

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FIG 11

FIG.9

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ATTORNEYS

3,792,884

LOCKING DEVICE

This application is a continuation-in-part of application Ser. No. 106,718, filed Jan. 15, 1971.

The present invention relates to a locking device for locking the drawer of a table, a door in furniture, or the like.

A principal object of the present invention is to provide a new locking device which can be easily moved into an engaged position by merely pushing a key and into a disengaged position by rotating the key.

A conventional simple locking device is provided with a biasing spring having a dead-point at which a male member or dead bolt is in an engaged position and a disengaged position. However, the useful life of such a spring in a dead-point type locking device is very short, because the spring receives various types of forces such as shock or the like whenever the position of the spring is changed.

Accordingly, another object of the present invention is to provide an improved locking device in which a biasing spring always forces a male member or male members in one direction toward the disengaging position, thereby increasing the useful life of the spring.

Other objects and advantages of the present invention will become apparent from the following detailed description and by reference to the accompanying drawings, wherein:

FIG. 1 is a vertical sectional view of a first embodiment of the locking device according to the present invention;

FIG. 2 is a side view of a key of the locking device of FIG. 1 showing an engaging position;

FIG. 3 is a perspective view showing a sliding member in the device of FIG. 1 and a part of the key;

FIG. 4 is an enlarged sectional view taken along the line 4—4 of FIG. 1;

FIG. 5 is a sectional view similar to FIG. 1, but showing the parts in the disengaged positions;

FIGS. 6 and 7 are perspective views of a part of a drawer showing the manner of mounting the locking device of FIG. 1;

FIG. 8 is a sectional view of a modified sliding member and key for the locking device of FIG. 1;

FIG. 9 is a vertical sectional view of a further embodiment of the locking device according to the present invention;

FIG. 10 is a perspective view showing a sliding member in the device of FIG. 9 and a part of the key; and

FIG. 11 is a sectional view similar to FIG. 1 but showing the parts in the disengaged positions.

A locking device in accordance with a first embodiment of the present invention as shown in FIGS. 1-7 comprises a main assembly A to be fixed to the back surface of the forward vertical wall, for example, of a drawer in a table, and a key member B for manipulating said main assembly.

The main assembly A includes a housing or main body 10 made, for example, of resinous material. Said main body has an open-topped longitudinal hole 11, a male member 12 slidably positioned in the hole 11 with a helical spring 13 therearound downwardly or inwardly biasing the male member 12 in the direction into the hole 11 from the open top. A hollow transverse cylinder 14 is integrally joined with the main body 10 and is in communication with the hole 11 at the lower end of the latter.

Slidably inserted in the bore 15 of the transverse cylinder 14 is a sliding member 16 in the form of a relatively thin plate, the forward portion of which is tapered to provide an inclined upper surface 17. Said sliding member 17 has at the forward end thereof a downwardly projecting stop 18 for limiting the sliding movement thereof and preventing removal thereof from the bore 15 of the cylinder 14 by its engagement with the inner surface of the hole 11 at 11α.

The sliding member 16 further includes a shallow recess 19 at the uppermost end of the inclined surface 17 for receiving a downwardly projecting lower edge 20 on the male member 12, a neck portion 21, and a pair of oppositely extending projections 22 at the end of the neck portion defining a pair of spaces 23 around the neck portion. To prevent rotation of the sliding member 16 around the axis thereof, a gate plate 24 having a gate 24α therein is positioned adjacent the inner end of the bore 15 adjacent the hole 11 and is fixed to the main body 10. The gate 24α is formed so as to allow the movement of the sliding member therethrough, but so as to prevent rotation of the sliding member. Further, said gate plate 24 serves as a stop for the stem 30 of the key B.

The above-described components are so arranged that when the sliding member 16 is pushed and moved to the innermost end of the bore 15 in the cylinder 14 during its sliding motion, that is, the left-most portion in FIG. 1, the lower edge 20 of the male member 12 rides up along the inclined surface 17 into the shallow recess 19 in the sliding member 16 to cause the upper end 12a of the male member to project from the upper end of the hole 11, said upper end 12a being adapted to engage in a recess 25 which is formed in a stationary part or frame 26, for example, of the table.

On the contrary, as shown in FIG. 5, when the sliding member is withdrawn to the right-most position in FIG. 5, the lower edge 20 rides down along the inclined surface 17 to the lower portion of the inclined surface 17 under the pressure of the spring 13, thereby withdrawing the upper end 12a within the hole 11.

The key member B for pushing and withdrawing the sliding member comprises a hollow cylindrical stem 30 and a head 32 at one end of the stem, said stem 30 being provided with two diametrally opposite spiral slits 31 opening at 33 out of the end of the cylindrical portion 30, said slits 31 being adapted to cooperate with the opposite projections 22 on the sliding member 16. Said cylindrical stem 30 has an outer diameter smaller than the diameter of the bore 15 in the cylinder 14 to allow insertion of the stem 30 into the bore 15.

In FIG. 1 the device is shown in the engaged position at which the upper or outer end of the male member 12 is engaged in the recess 25 in stationary frame 26. To release this engagement of the male member 12 in the recess 25, the stem 30 of the key B is inserted into the bore 15 and as the key B is manually rotated in the direction as illustrated by the arrow 34 in FIGS. 2 and 3, while maintaining pushing pressure on the key. During this rotation of the stem 30 the opposite projections 22 on the sliding member 16 are initially engaged in the openings at the beginning of the spiral slits 31, and then when the key is further rotated, the projections 22 are caused to slide along the spiral slits so that the sliding member 16 is withdrawn, and accordingly the male member 12 is moved down into the hole 11 by the

3,792,884 spring 13, as shown in FIG. 5. The device is now in the disengaged position.

On the other hand, the device can easily be placed in the engaged position, as shown in FIG. 1, by pushing the back surface of the sliding member 16 by the key B or any other bar or rod which can be inserted into the cylinder 14.

Preferably, the projecting edge 20, the gate plate 24, sliding member 16 and the stem 30 of the key are made of metal material to prevent wear or defacement of these parts by friction during sliding or the like.

The main assembly A can have various shapes. For example, it can have a shape as shown in FIGS. 6 and 7. In this embodiment, the main assembly A is for use in combination with a pair of elongated strip bars C. Each of said bars has at one end a mating surface 41 which conforms with the shape of the side 42 of the main assembly A. Further, each of the mating surfaces 41 is provided with two pins 43 to be inserted into apertures 44 of the main assembly. Accordingly, by using the strip bars C the main assembly A can easily be securely mounted on the back surface of the forward vertical wall 45 of a drawer 46 in a table as shown in FIG. 6.

It will be apparent that many modifications and variations can be made to the embodiment of the invention described hereinbefore. For example, the transverse cylinder 14 may be fastened removably to the main body 10. Also, spiral slits or grooves 31' can be fabricated in the sliding member 16, and opposite projections 22' can be formed on the end of the stem 30 of the key B, as shown in FIG. 8.

The locking device according to the present invention can be modified to have two male members which move in opposite directions to engage recesses at the top and bottom of a door. This embodiment of the locking device is shown in FIGS. 9-11 and comprises a main assembly to be fixed to the back surface of the forward vertical wall W, for example, of a door in a cabinet, and a key member for manipulating said main assembly.

The main assembly includes a housing or main body 10' made, for example, of resinous material. Said main body has a longitudinal hole 11' therethrough opening out of the opposite ends of the main body 10'. A male member 12' is slidably positioned in each end of the hole 11' with a helical spring 13' therearound inwardly biasing the male member 12 in the direction into the hole 11' from the open end. A hollw transverse cylinder 14' is integrally joined with the main body 10' and is in communication with the hole 11' at the center of the latter.

Slidably inserted in the bore 15' of the transverse cylinder 14' is a sliding member 16' in the form of a relatively thin plate, the forward portion of which is tapered to provide an inclined surface 17α on one side thereof and 17b on the other side thereof.

The sliding member 16' further includes a shallow recess 19' at the end of each of the inclined surfaces 17α and 17ft which are closest to the bore 15' for receiving inwardly projecting edges 20' on the male members 12', a neck portion 21', and a pair of oppositely extending projections 22' at the end of the neck portion defining a pair of spaces 23' around the neck portion. To prevent rotation of the sliding member 16' around the axis thereof, a gate plate 24' having a gate 24α' therein is positioned adjacent the inner end of the bore 15' adjacent the hole 11' and is fixed to the inner end of a cylinder 24ft tightly fitted in cylinder 14'. The gate 24α' is formed so as to allow the movement of the sliding member therethrough, but so as to prevent rotation of the sliding member. Further, said gate plate 24' serves as a stop for the stem 30 of the key B.

The above-described components are so arranged that when the sliding member 16' is pushed and moved to the innermost end of the bore 15' in the cylinder 14' during its sliding motion, that is, the left-most position in FIG. 9, the edges 20' of the male members 12' ride up along the inclined surfaces 17α and 17ft into the shallow recesses 19' in the sliding member 16' to cause the outer ends of the male members to project from the hole 11'. Said outer ends can engage directly in recesses formed in a stationary part or frame, in the same manner as shown in FIG. 1. However, where the locking device is mounted on a door, it is preferred to provide extensions 32 attached to the outer ends of male members 12', for example by being threaded into threaded holes in the outer ends of the male members 12'. The free ends 32a then project into recesses 33 in a stationary part or frame 34. The ends 32α of extensions 32 can be guided in guides 35 mounted on the back of door W.

When, as shown in FIG. 11, the sliding member is withdrawn to the right-most position in FIG. 11, the edges 20 ride along the inclined surfaces 17α and 17ft to the lower portions of the inclined surfaces under the pressure of the springs 13', thereby withdrawing the outer ends of members 12' within the hole 11' and withdrawing ends 32α of extensions 30 from recesses 33.

The key member B for pushing and withdrawing the sliding member 16' is identical with that for the embodiment of FIGS. 1-7 and operates in the same way, the sliding member 16' acting to move both male members 12' simultaneously.