JPH0513649B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] In a broad sense, the present invention relates to a storage or file unit in which movable storage bodies such as drawers are arranged in multiple stages. More specifically, the present invention relates to an improved interlocking device that prevents multiple bins from being activated (i.e., drawers being pulled out) at the same time.

[Conventional technology]

The file interlocks contemplated by the present invention are well known to those skilled in the art.

In use, in a storage unit comprising a plurality of vertically arranged storage bodies, such as drawers or shelves, which can be moved linearly, the drawers or shelves are returned to the storage position at the same time. If the cabinet or filing cabinet is tilted or pulled out, it is dangerous and the cabinet or filing cabinet may tip or fall.

Therefore, an interlocking device that can prevent multiple containers from being activated or pulled out at the same time has been desired for many years, and in order to develop an ideal interlocking device, Many attempts have been made.

Many of these known devices require significant modifications to the conventional cabinet or housing, and are complex and expensive in construction due to their interlocking with multiple storage units.

The structural and operational complexity of many known interlocks hinders the functionality of the housing and makes its operation cumbersome. Additionally, there was a risk that the interlocking device would not work properly and multiple containers would be pulled out at the same time.

In order to solve the obvious problem caused by pulling out a plurality of storage bodies at the same time, an interlocking device is provided which simplifies and simplifies the structure and operation, and which can operate extremely reliably to prevent errors. Many attempts have been made to date.

These linkage devices typically include a connecting rod associated with a linearly movable storage body and a plurality of vertical connecting rods arranged in vertical rows.

In most cases, this connecting rod is adapted to be actuated by one element that cooperates with a movable cam or web and is connected to a linearly moving storage body.

In many known devices of this type,
The cam or web is movably supported directly, for example, on the lower end of the locking rod. In some models, the movable cams are mounted completely independently between adjacent actuating rods. That is, the plurality of rods are not supported by separate rods, but by intermediate cams.

In some storage units, the locking rod and actuating cam are vertically aligned when the storage object moves linearly, but the associated cam movement is extremely complex.

Furthermore, multiple locking rods arranged vertically,
Some are designed to operate in opposite directions at the same time, but their control and suppression are more complex.

Many known interlocking devices have one or more of the features of the latter mentioned above and provide sufficient reliability for the interlocking function.

However, according to experience, although the risk of two drawers being pulled out at the same time has been significantly reduced, it has not been completely eliminated and cannot be said to be absolutely safe.

Furthermore, one of the major inherent problems with conventional interlocking devices for movable enclosures is that as the number of enclosures increases, the accumulation of manufacturing errors increases, eventually rendering the operation incomplete and not working as originally intended. On the other hand, two storage bodies may be pulled out or stored at the same time.

There are many examples of interlocking devices suitable for filing cabinets having a plurality of movable storage bodies, such as drawers. Among them, those that are largely related to the present invention and are considered to be the basis of the present invention are, for example, United States Patent No.
No. 3900236, No. 4272138, No. 4298236, No. 4355851, No. 4429930, No. 4441767,
It is described in the specifications of the same No. 4447098 and the same No. 4480383.

[Purpose of the invention]

It is an object of the present invention to provide an improved interlocking device that overcomes many of the problems in conventional interlocking devices.

More specifically, to provide an interlock device that ensures that only one storage unit or drawer can operate at a time when the filing unit is used under appropriate loads and conditions. It is in.

The improved interlock of the present invention includes a plurality of vertical locking rods in vertical alignment with each other, each locking rod being capable of vertical displacement by a limited amount to It is installed inside the ring cabinet.

A locking cam is rotatably supported on the upper end of the locking rod and is actuated by an actuating pin on each linearly moving storage or drawer.

The locking cam does not interfere with the vertically overlapping locking rods when multiple storage objects are stored.

When one storage body is pulled forward from its storage position, the actuating pin contacts the locking cam, rotates the cam, and moves upwardly, raising only the locking rod. As a result, the locking rod is supported by the cam and is reliably supported in the pushed-up position.

As a result, the vertically arranged locking rods are firmly fixed and will not move even slightly from their positions. Therefore, until the pulled-out storage object is pushed back to the initial position, that is, the storage position, no other storage object can be pulled out.

A second object of the invention is to minimize the cumulative vertical error caused by the vertical locking rod and rotating locking cam component, so that each storage To provide an extremely simple and reliable interlocking device which allows only one piece to be pulled out.

A third object of the present invention, as mentioned above, is to provide an improved interlocking device which is extremely simple in structure and operation and can be manufactured and assembled efficiently.

Other objects of the invention, read the following description:
I think this will become clear to the engineers concerned by referring to the attached drawings.

〔Example〕

Some of the terms used in the following description are for convenience and not limitation.

For example, "upward", "downward", "rightward", and "leftward" indicate directions in the drawings.
"Inwardly" and "externally" refer to directions toward and away from the geometric center of the device.

Certain terms include the meaning specifically mentioned, as well as derivatives and synonyms thereof.

All drawings, FIGS. 1 and 2, show a conventional office filing cabinet or storage unit 10 comprising a plurality of movable storage bodies or drawers 11 disposed vertically relative to each other within the interior of the cabinet or housing 12. It is shown.

The drawer 11 is capable of linear movement horizontally with respect to the cabinet 12 between its open and closed states. To this end, as shown in FIG. 1, each drawer 11 is supported on both sides in the cabinet 12 by conventional ball-mounted extendable rails 13.

Drawers 11 as movable storage bodies (usually two to six drawers are provided inside the cabinet 12, but in this embodiment, there are three drawers).
The can be a regular drawer or a shelf.

Drawer 11 typically has a door or front plate 14 which, when closed, is flush with the front opening of the cabinet, such as the upper and lower ones in FIG. The middle one of the drawers 11 with the front plate 14 is shown slightly open for loading and unloading the contents.

The drawer 11 shown in FIGS. 1 and 2 is integrated with the front plate 14.
Alternatively, it may be a conventional linearly moving shelf, in which case the front plate 14 may be hinged or slidably mounted to the cabinet 12 for independent operation.

Cabinet 12 is provided with an interlocking device 16 according to the invention to allow only one drawer to be opened at a time.

The interlocking device 16 includes a plurality of locking rods 17 associated with each drawer 11 and aligned vertically.

The drawers 11 are designed to withstand the load of the overlapping drawers when all the drawers are closed.
The bottom drawer 11 is located on the bottom plate 18 of the cabinet.
is being pressed.

The locking rod 17 is lowered toward the bottom plate 18 by gravity, but in order to ensure reliable and quick operation, it is desirable to apply a counterforce using a spring.

The interlocking device 16 includes a plurality of elongated lock rods 17 corresponding to the number of drawers 11, and a top lock piece 19 that is short in the vertical direction and into which the upper end of the uppermost lock rod 17 can be fitted in a telescopic manner. ing.

The lock piece 19 is attached to the top plate 23 of the cabinet 12.
It is very small in size.

The upper surface 21 of the lock piece 19 is connected to the cabinet 12.
The lock piece 19 is located directly below the stop surface 22 on the lower surface of the top plate 23 of the drawer, and when one of the plurality of drawers is pulled out and the interlocking device is activated, the lock piece 19 is prevented from rising further and another The drawer is designed to never open.

The top lock piece 19 is attached to the top drawer 11.
However, when it is closed, it abuts against the upper end surface of the lock piece 17 at the upper end.

A pair of conventional compression coil springs 24 are attached to the stop surface 2.
2 and the top locking piece 19, and the locking rod 17 and the locking piece 19 are pushed downward.

Vertically aligned locking rods 17 are vertically slidable in vertical shallow groove rods 26 (FIG. 3) secured to the inner surface of sidewall 27 of cabinet 12. The groove rod 26 holding the lock rod 17 opens toward the side of the drawer 11, that is, toward the inside.

In the interlocking device 16 of the present invention, a rotatable locking cam 31 is provided near the upper end of each locking rod 17.

Each locking cam 31 is connected to a locking rod 17 provided with the locking cam 31.
When the associated drawer 11 comes out of the storage position,
It engages with the locking rod 17 directly above it to raise it.

As each drawer is pulled out, the locking cam 31
It is actuated by engaging an actuation pin 29 that projects laterally from the side wall of each drawer. The operation of this locking cam 31 and its cooperation with the locking rod 17 will be explained in detail later.

The structure of the locking rod 17 shown in FIGS. 4 and 5 will be explained.

This consists of a pair of vertically elongated end walls 33.
and a central web 32 connecting them,
It has an I-shaped cross section. Both end walls 33 are connected to the lower end surface 34 of the locking rod 17, that is, the central web 32.
It ends slightly above the lower end surface 34 defined by.

This lower end surface 34 is a generally horizontal flat surface.

A vertical reinforcing rib 36 is preferably provided at the center of the central web 32 of the locking rod 17 in the longitudinal direction.

The upper end surface 37 of the locking rod 17 coincides with the upper end surface of its central web 32. From one corner of this upper end surface to about half the width of the locking rod 17,
A notch 38 is provided. This notch 38
is directed downward from the upper end surface 37 and inward from the end wall 33. The bottom surface 39 of the notch 38 is
It is located below the upper end surface 37 of the locking rod 17. This bottom surface 39 passes through the slope 41 and the upper end surface 3
It is connected to 7.

A slot 42 is provided on the upper end surface of the locking rod 17 into which the locking cam 31 is rotatably inserted. This slot 42 is provided in the central web 32 and extends downwardly from the upper end surface 37 of the locking rod 17 by the required amount. Both side edges 43 of the slot 42 are oriented vertically downward. The lower ends of both side edges 43 of the slot 42, which are parallel to each other, form semicircular receiving surfaces 44 for rotatably supporting the locking cam 31.

This semicircular receiving surface 44 is perpendicular to the central web 32 and extends from the rotation axis 4 which is approximately an extension of the bottom surface 39.
It is centered around 6. The axis of rotation 46 is close to the end wall 33 of the locking rod 17 remote from the notch 38 and is laterally offset from the centerline of the locking rod 17.

The locking rods 19 and 17 at the top are
Preferably, it is made of a hard plastic material, such as ABS plastic. The locking cam 31 is integrally formed, for example, by molding of a hard plastic material, and includes a spool-shaped hub for rotatably mounting within a slot 42 provided at the upper end of the locking rod 17. .

As shown in FIGS. 6 to 10, the locking cam 3
The spool-like hub in 1 includes a cylindrical bearing portion 48 located between a pair of generally parallel lateral flanges 49 . The diameter of the hub is such that it is rotatably supported within the receiving surface 44. The side flanges 49 are arranged with a width slightly larger than the thickness of the central web 32 in order to rotatably hold the locking cam 31 on the upper part of the locking rod 17.

The side flange 49 is provided with a lever-like arm 51 which is integral therewith and projects radially from the cylindrical bearing part 48 . Moreover, between the two arms 51, the central web 3
Part 2 is fitted.

The free ends of the two parallel arms 51 are connected via a cam piece 52.

As shown in FIG. 10, the cam pieces 52 are arranged at constant intervals in the radial direction from the bearing part 48. a pair of generally flat cam surfaces 53, 54;
are formed, and these cam surfaces 53 and 54 are generally orthogonal to each other and have a rounded corner 55.
connected by.

The arm 51 also includes a flange 56 that projects outward from the cam surfaces 53 and 54. The spacing between the flanges 56, 56 is approximately equal to or slightly greater than the width of the central web 32, so that the central web of the locking rod 17 extends beyond the width of the flange 5.
It can fit between 6 and 56.

A pair of arms 51 parallel to each other and a cam piece 52 located between them rotate the locking cam 31 when the drawer 11 is pulled out from the storage position, as will be described later, and lock the lock directly above it. Rod 1
A cam portion 58 is configured to operate to raise 7.

The locking cam 31 includes a lever 59 that contacts an actuating pin 29 at the top of the drawer 11 so that it can be rotated when the drawer 11 is moved in a linear direction.

This lever 59 is arranged adjacent to one side of the central web 32 of the locking rod 17, in particular adjacent to the innermost side, so that it is located within the path of movement of the actuating pin 29. . This lever 59
1 protrudes radially outward from the large diameter hub 63
A pair of arms 61 and 62 are provided. Large diameter hub 6
3 is coaxial with the central bearing part 48,
It is integral with one side flange 49 and projects outward therefrom.

The angle between these arms 61 and 62 is, for example, less than 90 degrees, and they are separated by a recess 64.

Both arms 61, 62 are generally in the same plane, but arm 61 is considerably longer than arm 62. Both arms 61, 62 are formed as part of one continuous rib along the outer edge of a single plate-like lever 66, although this is solely for manufacturing convenience.

In the normal position, ie, when each drawer 11 is stowed, the long arm 61 faces generally downward from the axis of rotation 46, and the short arm 62 faces generally rearward with respect to the cabinet.

When the drawer 11 is pulled out, the locking cam 31 is rotated through an angle of about 90 degrees between the unlocked position and the locked position shown in FIGS. 11 and 12, respectively.

Therefore, the positions of the arms 61 and 62 change as shown in FIG. 1, with the long arm 61 generally facing forward and the short arm 62 generally facing downward.

〔operation〕

The operation of the interlocking device of the present invention will now be briefly described in order to provide a thorough understanding.

When all the drawers 11 of the storage unit 10 are stored, the vertically arranged locking rods 17 and the top locking pieces 19 contact each other, and the lowermost locking rod 17
contacts the bottom plate 18 of the cabinet. The top surface 21 of the top locking piece 19 is located at a distance L (FIG. 12).
A distance equal to or slightly greater than
It descends from the top 22.

In this position, the lower end surface of the uppermost locking rod 17 is in contact with the upper end surface of the locking rod 17 directly below it. Further, the lower surface of the top wall of the top locking piece 19 is in contact with the upper end surface 37 of the locking rod 17 at the upper end.

Each locking cam 31, like the one at the bottom in FIG. 1, is tilted slightly backwards, with the long arm 61 facing downward and the short arm 62 facing rearward.

The operating pin 29 provided on the side of each drawer 11 is
It is located a certain distance slightly behind the long arm 61. The actuating pin 29 is located at a slightly lower level than the short arm 62, and therefore can pass under the short arm 62 and move horizontally forward without contacting the short arm 62. However, as the drawer 11 moves forward, it comes into contact with the long arm 62.

The locking cam 31 is provided with a cam piece 52 that can perform its predetermined function as shown in FIG. 11 when it is in the unlocked position. The cam piece 52 has a notch 38
and is in contact with the bottom surface 39 thereof. Also, the cam piece 52 is connected to the locking rod 17 directly above it.
It is in contact with the lower end surface of.

The flanges 56 on both sides of the cam piece 52 project upwardly and pinch the central web 32 of the locking rod 17 directly above them.

In this way, the locking cam 31 is connected to the locking rod 17 directly above it, converting rotational movement into vertical and linear movement.

Further, the locking cam 31 is positioned between the locking rods 17, and the locking rods 17 are arranged in a straight line in the vertical direction.
7, it can rotate in a controlled manner.

Place one of the drawers 11 into the middle drawer 1 in FIG.
1, when moved forward, the operating pin 29 contacts the long arm 61 and locks the locking cam 31.
Rotate clockwise approximately 90 degrees forward. As a result, the arm 61 generally protrudes forward, and the drawer 11
The actuating pin 29 provided at the locking cam 31 moves forward and away from the locking cam 31.

While the locking cam 31 is rotating clockwise forward about 90 degrees, the cam piece 52 rotates upward and backward and comes into contact with the lower end surface 34 of the locking rod 17 directly above it. Therefore, the locking lever 17 immediately above rises, and the locking cam 31 moves to the position shown in FIG.
It slides along the lower end surface 34 of the locking rod 17.

In this position, the bearing portion 48 of the cam piece 52 is rotatably supported in the slot 42 of the locking rod 17, so that the upper locking rod 17
is raised a distance L above the upper end surface 37 of the lower locking rod 17.

As shown in FIGS. 11 and 12, when the cam piece 52 moves from the unlocked position to the locked position,
The cam piece 52 moves beyond the rotating shaft 46. That is, when in the locked position shown in FIG. 12, the cam piece 52 contacts the lower end surface 34 of the upper locking rod 17 at the rear of the rotating shaft 46. Also, the 11th
When in the unlocked position shown in the figure, it is in front of the rotating shaft 46.

Also, the flange 56 is connected to the end wall 33 of the locking rod 17.
The locking cam 31 stops at the position where it makes contact with the locking cam 31.
is held in a locked position beyond the rotating shaft 46 as shown in FIG.

The locking cam 31 is arranged so that it can be raised by a distance L relative to the locking rod 17 directly above it and the top locking piece 19, as in the locked position shown in FIG. The top lock piece 19 is raised against the bias of the compression coil spring 24 so that its upper surface abuts against the stop surface 22.

In this state, the locking cams 31 of the vertically aligned series of locking rods 17 and locking pieces 19 are
In the activated or locked condition, the locking lever, which is in contact with the upper stop surface 22 and the bottom plate 18 of the cabinet, cannot be operated.

When the drawer is pulled out, its operating pin 29 abuts against the long arm 61 of the locking cam 31. Therefore, the locking cam 31 rotates and locks the locking rod 1 directly above it.
Raise 7.

When the drawer 11 is closed, the actuating pin 29 contacts the short arm 62 and rotates the locking cam 31 counterclockwise from the position shown in FIG.
Return to the position shown in the diagram. Due to this action, the interlocking device returns to its original state and only one drawer is opened.
It can be opened.

Although the above description deals with opening the middle drawer, it is obvious that the interlocking function operates in exactly the same way when opening the bottom drawer. Similarly, opening the top drawer basically works in the same way. However, in this case, each locking cam 31 raises only the top locking piece 19.

If you try to pull out two drawers at the same time, the rotation of the locking cam 31 for each drawer will be restricted, none of the locking cams will rotate sufficiently, and the actuating pin 29 will move forward. prevent them from doing so. Therefore, the interlocking device will lock any drawer.

To unlock one of the two drawers, return at least one drawer to the storage position,
Then just open the other drawer.

In the improved interlocking device of the present invention, the cam piece 52
is associated with the adjacent locking rod 17, and engages with both sides of the central web of the locking rod directly above it.
Since the two flanges 56 are provided, the locking cam 31 is properly supported.

Moreover, its movement is controlled at all times, and the locking cam 31 is supported within the slot 42 without the need for any other retaining means.

Further, since the locking rods 17 are in direct contact with each other when the locking cam 31 is in the unlocked state, the locking cam is free from interference and the sum of errors resulting from a vertical series of components. There will be no increase.

As a result, the dimensional overlap of the interlocking devices is small;
Accurate control is possible, and inadvertent malfunctions are minimized.

Furthermore, a lock lever 17 that interlocks with the drawer 11
is not displaced vertically by itself, but when the shaping cam 31 provided thereon rotates, it raises the upper locking rod 17.

Therefore, the locking rod 1 must be raised.
7 is minimized, and the dimensional tolerances and interaction of the actuating pin 29 and the movement pattern associated with the pin 29 and each locking cam 31 are minimized.

As is clear from the above explanation, locking rod 1
7 and the number of top locking pieces 19 is one more than the number of drawers, ie the number of storage elements 11. however,
The lowest locking lever 17 does not move vertically during operation of the interlock and rotatably supports the locking cam 31.

Although specific embodiments of the present invention have been described above in detail, it goes without saying that the present invention can be modified in various ways, including rearrangement of parts, within its technical scope.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of a main part showing the interlocking device of the present invention in conjunction with a plurality of movable storage bodies, that is, drawers, in a storage unit. Figure 2 shows
FIG. 2 is a longitudinal sectional front view of main parts of the interlocking device shown in FIG. 1, with some parts omitted for clarity.
FIG. 3 is a partial sectional view taken along line - in FIG. 1. FIG. 4 is an enlarged side view of the locking rod. FIG. 5 is a front view of the locking rod shown in FIG. 4. FIG. 6 is a side view showing the locking cam enlarged at the ratio shown in FIG. 4. FIG. 7 is a right side view of the locking cam shown in FIG. 6. FIG. 8 is a plan view of the locking cam shown in FIG. 6. 9th
10 are cross-sectional views taken along lines - and - in FIG. 8, respectively. FIG. 11 is a partial front view showing the cooperative relationship between adjacent locking rods and locking cams when the locking lever is not in operation, that is, when it is stored. FIG. 12 is a view similar to FIG. 11 showing the locking cam in operation, that is, in locking. Figure 13 shows the line in Figure 12 --
FIG. 10...Storage unit, 11...Drawer, 12
... Cabinet, 13 ... Rail, 14 ... Front plate, 16 ... Interlocking device, 17 ... Lock rod, 1
8... Bottom plate, 19... Top lock piece, 21... Top surface, 22... Stopping surface, 23... Top plate, 24... Compression coil spring, 26... Groove rod, 27, 28... Side wall, 29... ...Operating pin, 31...Lock cam, 32
... Central web, 33 ... End wall, 34 ... Lower end surface,
36...Reinforcement rib, 37...Top end surface, 38...Notch, 39...Bottom surface, 41...Slope, 42...Slot, 43...Side edge, 44...Best surface, 46...
Rotating shaft, 48...Bearing part, 49...Side flange, 51...Arm, 52...Cam piece, 5
3, 54...cam surface, 55...corner, 56...flange, 58...cam part, 59...lever, 6
1, 62...Arm, 63...Large diameter hub, 64...
...Recessed part, 66...Plate lever.

Claims (1)

[Claims] 1. In order to interlock the storage bodies generally horizontally and linearly between the open state and the closed state, the storage bodies are arranged vertically in parallel inside the cabinet and are movably supported. In the storage unit, the storage unit includes an interlocking device that is linked between the cabinet and the plurality of storage objects to open the cabinet, the plurality of storage objects, and only one storage object. an elongate guide means provided on a side of the cabinet in a generally vertical direction between an upper end and a lower end of the cabinet to define a vertically oriented guide passage; and upper and lower stops respectively disposed adjacent to the lower ends and fixedly provided at the upper and lower ends of the guide means, respectively; and vertically along the guide path. a plurality of vertically oriented locking rods arranged in a straight line; a top locking piece disposed above the uppermost locking rod so as to be slidably movable along the guideway; an equal number of rotatable locking cams engaged with the locking rod and rotating each locking cam as each housing moves in a direction toward an open position away from the closed position; , an operating body provided in each of the storage bodies, the number of locking rods being equal to that of the storage bodies,
and a locking rod is disposed close to a side portion of the storage body, the locking rod has an upper and a lower abutting portion, and a lower abutting portion of the lowest locking rod has an upper and a lower abutting portion. , is located adjacent to the lower stop, and the lower abutment of the other locking rod is in contact with the upper abutment of the locking rod immediately below it when the interlock is in the unlocked position. The top locking piece is adapted to be in close engagement with an upper abutment portion of the top locking rod when the interlocking device is in the unlocked position. and wherein the top locking piece has an upper abutment that is spaced downwardly from the upper stop by a predetermined distance when the interlock is in the unlocked position. The rotating locking cam is rotatably supported by the locking rod adjacent to its upper end, and each of the locking cams is rotatably supported by the locking rod adjacent to its upper end. The locking cam has a cylindrical bearing portion that allows the locking cam to rotate about a generally horizontal axis of rotation in each locking rod, and the locking cam is configured such that each storage body is in an unlocked position. When moving from the lock position to the lock position, the lock rotates at a specified angle.
an arm projecting radially from the rotating shaft for engaging the actuating body; , when the cams are rotated toward the locked position and away from the unlocked position, the cams operate by directly engaging only the bearing surface directly above the cams, and are arranged at regular intervals radially from each rotation axis. and by rotating one of the locking cams to the predetermined distance, the rotation of the other locking cams is prevented and the same cam is supported in its locked position. An interlocking device for a drawer unit, characterized in that: 2. said locking rod has a vertically extending central wall and has upper and lower bearing surfaces adjacent to its upper and lower ends, respectively, and the locking cam is configured to form a narrow groove; , having a pair of outwardly projecting side flanges, said side flanges being configured to engage the locking cam when the locking cam is operated in its unlocked and locked positions, or between these positions. 2. An interlock for a drawer unit as claimed in claim 1, characterized in that it projects upwardly for engaging the lower end of the center wall of the locking rod directly above. 3. The locking rod has a slot opening downwardly from the central wall from each upper bearing part, said slot terminating in said bearing part, and each said locking cam having a slot connected to said bearing part. 3. The locking rod according to claim 2, wherein the locking rod is freely positioned and supported on each locking rod by being moved downwardly through the upper end of the slot for rotational engagement. Interlocking device for the drawer unit described. 4. A slot is disposed adjacent one side of the central wall along the vertical centerline, at which point a groove is formed in the central wall of the locking rod adjacent to the other side; The groove accommodates the locking cam therein when each locking cam is in its unlocked position, and the locking cam is arranged at a location radially at a constant distance from the bearing portion. 4. The interlock for a drawer unit according to claim 3, further comprising a pair of arms which are adapted to be firmly connected to both sides of the drawer unit and project radially from the bearing portion toward the central wall. Device. 5. By rotating the locking cam from the unlocked position to the locked position, the locking cam is moved beyond the central position so that when in the locked position, it is on one side of the vertical plane with the rotating shaft. 5. The interlocking device for a drawer unit according to claim 4, wherein the cam is moved by the drawer unit, while being located on the opposite side of the vertical plane when in the unlocked position.