US3125873A

US3125873A - Locking mechanism

Info

Publication number: US3125873A
Authority: US
Publication date: 1964-03-24
Anticipated expiration: 1981-03-24

Description

March 24, 1964 M. A. ROBINSON LOCKING MECHANISM Filed Sept. 10, 1962 IIIIIIIIIIIIIIIII INV EN TOR. flme/rr A. 206/460 United States Patent 3,125,873 LOCKING MECHANEM Merritt A. Robinson, Marin County, alif., assignor t0 Kimball Manufacturing Qorporation, San Rafael, Galifi, a corporation of California Filed Sept. 10, 1%2, Ser. No. 222,6% 9 Claims. (Cl. 70-63) This invention relates to a locking mechanism and more specifically to a locking mechanism having flexible tumbler portions and designed for minimum security purposes.

The present invention finds particular utility in household containers such as boxes or cabinets wherein medicines, household chemicals and other dangerous items are to be kept away from children. For such purposes, a lock is required which will keep the container securely closed but which will enable the container to be opened easily when desired. Since small children are equipped with but limited coordination and mechanical knowledge, it is not necessary that a lock be unduly complicated to perform the necessary locking function. It is the primary object of the invention to provide such a lock.

A further object of the invention is to provide an inexpensive locking mechanism which can be molded integrally with a plastic container.

Although the present invention finds utfiity in connection with household containers, it is to be realized that the use is not necessarily limited thereto. Instead, the present invention has widespread application where it is desired to provide an inexpensive lock for fastening two members together.

Other objects and advantages will become apparent in the course of the following detailed description.

In the drawings which form a part of this application and in which like reference numerals are used to indicate like parts throughout the same,

FIG. 1 is a perspective view of a container and key embodying the principles of this invention;

FIG. 2 is a plan view in enlarged scale of the locking mechanism of FIG. 1;

FIG. 3 is a sectional view taken on lines 3-3 of FIG. 2;

' FIG. 4 is a sectional view taken on lines 4-4 of FIG. 2, showing the mechanism in locked position;

FIG. 5 is a side elevational view of the key utilized in the present invention;

FIG. 6 is an end elevational view of the key of FIG. 5;

FIG. 7 is a sectional view, similar to FIG. 4, showing the key being utilized to move the locking tumblers to unlocked position; and

FIG. 8 is a plan view of the showing of FIG. 7, illustrating the parts in their unlocked position. 7

Referring now to the drawings wherein is illustrated a preferred embodiment of the invention, reference numeral 10 refers generally to the container which comprises a lid member 11 and a body member 12 which lid and body members are joined together by hinges such as are indicated generally at 13. Also fllustrated in FIG. 1, is a key 14 shown in general positionto cooperate with the "ice are two aligning apertures or

slots

25 and 26. As is noted, the

aligning apertures

25 and 26 extend into the recess 15 and intersect the locking apertures 16 and 18.

The container body 12, which is preferably an injection molding of polypropylene, has provided therein as an integral part thereof three

tumblers

27, 28 and 2%, which are integrally molded with an internal partition 30 of the body 12. As is shown in FIG. 4, the tumbler member 28 has a reduced-thickness neck 31 which enables the tumbler member to flex slightly to the left and right as viewed in FIG. 4. The tumbler 28 has the upper portion 28a thereof extending through the locking aperture 17 and when the tumbler member 28 is in its unfiexed position shown in FIG. 4 the locking shoulder 32 formed on the tumbler portion 28a hooks over and engages the locking shoulder 21 of the locking aperture to prevent the lid and body from being opened relative to each other.

It will also be noted that the portion 28a of the locking tumbler 28 which projects through the locking aperture is completely within the recess 15 of the lid and does not extend thereabove. This enclosure of the tumblers in the recess makes it very difiicult to open the lid without the use of key 14. The over-all width of the tumbler 28, from the locking shoulder 32 to the opposite side thereof, is less than the distance betwen the

opposite shoulders

21 and 22 of the locking aperture.

In like fashion, the

tumbler members

27 and 29 extend through the locking apertures 1'5 and 18, respectively, and the tumblers are provided with locking shoulders 33 and 34, respectively, which engage the locking shoulders 19 and 23 of the apertures 16 and 13 when the tumblers are untiexed.

The tumbler member 28 has a recess 36 formed into the end thereof which is provided with a cam surface 37 for use in unlocking the tumbler, as will be described hereinafter. Similarly,

tumblers

27 and 29 are provided with recesses 38 and 39 into the ends thereof, which recesses are provided with unlocking cam surfaces 4-9 and '41, respectively.

FIG. 5 illustrates the key 14 utilized for unlocking the tumblers of the invention; As is noted, key 14 is provided with five depending prongs, the outermost being alignment prongs 42 and 43 for cooperation with the

alignment apertures

25 and 26 of the lid. The intermediate unlocking prongs 44, 45 and 46 are designed to cooperate with the

recesses

38, 36 and 39 of the tumblers, respectively.

To open the container 10, the alignment prongs 42 and 43 of the key are inserted into the

alignment apertures

25 and 26 of the lid. As the key is moved downwardly, the unlocking prongs 44, 45 arid 46 enter the locking mechanism of the container 10 to unlock the lid from the body 12. 7

As best seen in FIGS. 2, 3 and 4, the lid 11 is provided with a recess 15 in the top thereof. Three generally rec tangular locking apertures 16, 1'7 and 13 are formed through the bottom of the lid recess. Locking aperture i 16 has a locking shoulder 19 and a shoulder 20 opposite thereto. Likewise, locking aperture 17 has a locking shoulder 21 and a shoulder 22 opposite thereto, and locking aperture 13 has a locking shoulder 23 and a shoulder 24 opposite thereto. Also formed through the lid 11 recesses in the ends of the tumblers. The cam surface 47 of prong 45 engages the cam surface 37 of recess 36 in tumbler 28, and the downward movement of the key relative to the tumbler causes the tumbler 28 to flex slightly to the right, to the position shown in FIG. 7, so that the unlocking shoulder 32 on the tumbler clears the unlocking shoulder 21 of aperture 17. In' like manner, the cam surface 48 on key prong 46 engages the cam surface 4-1 of tumbler 29 so that the tumbler 29 is flexed slightly to the left, to the position shown in FIG. 7, so that the unlocking shoulder 34 thereof clears the locking shoulder 23 of aperture 18. In like manner, the tumbler 27 is moved to its unlocking position by the unlocking prong 44 of key 14. When the key 14 has been moved downwardly as far as it goes, all of the

tumblers

27, 28 and 29 will be unlocked so that the lid may be opened. The key may be left in place, if desired, as the lid is opened. a

After the lid has been opened, the key may be removed. The tumblers will now return to their unflexed positions shown in FIGS. 2 and 4. In order to allow the lid to close, the

tumblers

27, 28 and 29 are provided with

inclined cam surfaces

51, 52 and 53, respectively, for cooperation with the

locking shoulders

19, 21 and 23 of the locking apertures 16, 17 and 18. For example, the locking shoulder 21 of aperture 17 will engage the inclined cam surface 51 of tumbler 28 causing the tumbler 28 to flex slightly to the right so that the tumbler may pass through the locking aperture 17. When the lid is completely closed, the flexibility of the tumbler will cause it to snap over into hooked engagement with the locking shoulder of the aperture so that the lid is again secured. In like manner, the other two

tumblers

27 and 29 will be cammed to their unlocking position as the lid is closed and they also will snap into hooked engagement with the locking shoulders of their respective locking apertures when the lid is completely closed.

The

tumblers

27, 2S and 29 are also designed so that they will not unlock if they are flexed beyond their unlocking position. As shown in FIG. 7, when the tumbler 28 is in its unlocking position, the locking shoulder 61 thereon clears the shoulder 22 of the locking aperture 17 so that the tumbler can pass through the locking aperture. However, if the tumbler 28 is flexed too far to the right, the locking shoulder 61 of the tumbler will engage the aperture shoulder 22 to prevent unlocking. This construction prevents accidental unlocking by merely pushing the tumbler all the way to its right, as might be done by a child. The

tumblers

27 and 29 are similarly formed for cooperation with the

shoulders

20 and 24 of the locking apertures 16 and 18, respectively.

As may be seen from the foregoing description, an inexpensive locking mechanism has been provided which will enable the box to be securely fastened when the lid is closed but which will at the same time permit easy access into the box by means of the key 14.

Although the tumblers have been shown in the drawings as being in a slightly staggered row when unfiexed, it is to be realized that the tumblers in their unfiexed position could all be in a row, aligned with one another. In such event, the locking apertures in recess would have to be slightly rearranged so that the locking shoulders of the locking apertures would underlie the locking shoulders of the tumblers when the tumblers are in their unfiexed position. If such a modification were made, the unlocking and locking would take place in exactly the same manner as previously described. Similarly, the locking apertures 16, 17 and 18 could all be in a row, aligned with one another. In such an event, the tumblers would have to be originally molded in a much more staggered unfiexed relationship than shown, in order that the locking shoulder of the tumblers would overlie the locking shoulder of the apertures when the tumblers are in their unfiexed positions. However, the principle of operation would remain the same.

It is also possible that the tumblers, which are shown in the figures as adjacent one another, could be slightly spaced apart. In this case, separated locking apertures could be provided. However, if the apertures and tumblers are arranged in such manner that the tumblers, when unfiexed, have the locking shoulders thereon overlying the locking shoulders of the apertures and the apertures are of a width wider than the width of the tumbler, the principles of the present invention would still be employed.

As an even further modification, the tumblers could be arranged in some other manner than in a row. For example, the tumblers could be arranged in a generally circular manner with either individual locking apertures being provided for each tumbler or merely one large aperture provided in such manner that the locking shoulders of the tumblers would overlie the edge of the locking aperture. In order for the tumblers to be then unlocked in the last instance, they could be moved to- 4. ward the center of the one large aperture, away from their hooked engagement with the shoulder of the aperture.

Other configurations utilizing the principles of this invention will suggest themselves. However, in any of these arrangements it is considered essential that at least two of the tumblers move in different directions in order to unlock the lid. There are at least two reasons for this requirement. One reason is that if all tumblers moved in the same direction to unlock the lid, it would be quite easy for a small child to accidentally manipulate the tumblers in this direction to open the lid, thereby defeating one of the main objects of the invention. Another reason for the different direction of movement of the tumblers to their unlocking position is that unlocking cannot occur because of relative sliding movement of the lid on the body of the box. As may be appreciated, one of the purposes of the present invention is to provide locking mechanisms for inexpensive, plastic containers, which containers have a relatively high degree of flexibility. If all of the tumblers were movable in the same direction to their unlocking position, it would be quite possible for the box to accidentally open by a sidewise shifting movement of the lid relative to the body in the opposite direction which would cause the unlocking shoulders of the tumblers and apertures to disengage. This, however, is prevented when the tumblers have to move in different directions to their unlocking positions. Thus, if the lid were shifted to unlock one tumbler, at least one other tumbler would still lock the lid closed.

Although the preferred embodiment of the invention which is illustrated herein is shown as having three tumblers, it is to be realized that the invention is not limited to that precise embodiment, but that any number of tumblers from two on up may be used as desired.

The present invention, as described, has been formed by injection molding of polypropylene. However, it is to be realized that other materials could be used for the formation of the locking mechanism, as long as the tumblers have sufiicient flexibility to enable them to be flexed back and forth from their locking to their unlocking positions, in the manner as described herein.

Although the particular embodiment of the invention illustrated herein has been depicted as used with a box having a hinged lid, it is to be realized that the invention could be used with other types of door members. For example, the invention would find utility in a sliding door arrangement, wherein the tumblers were carried on the sliding door and the locking apertures were provided in the door frame. Naturally, the opposite arrangement could be made, if desired.

Still another change that could be made would be to bridge over the top of the recess to provide only a narrow slot for the insertion of the key into the recess. Such construction would be slightly more expensive, but it would increase the security of the locking mechanism since it would prevent entry of little fingers into the recess.

As may thus be appreciated, the embodiment of the invention described herein is merely a preferred embodiment of the same, and various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the attached claims.

Having thus described my invention, what I claim and deisre to secure by Letters Patent is:

1. Locking mechanism for locking two members when closed, comprising:

one of said members having a plurality of locking apertures therethrough, said locking apertures each having a locking shoulder and another shoulder opposite thereto;

a plurality of flexible tumblers on the other of said members, said other of said members and said tumblers thereon comprising an integrally molded plastic member, each tumbler being associated and in alignment with one of said locking apertures, each tumbler having a portion thereof projecting through its associated locking aperture when said members are closed, which portion has a locking shoulder thereon normally hooking over the locking shoulder of the locking aperture when said tumblers are unflexed, the tumbler portions each having an over-all width less than the distance between the opposed shoulders of the associated locking aperture, said tumblers each being flexible to an unlocking position wherein the locking shoulders of said tumbler and locking aperture are out of hooked engagement, said locking apertures and tumblers being arranged so that at least two of said tumblers flex in different directions to their unlocking positions;

interengageable cam surfaces on said tumblers and said one member for flexing said tumblers to their unlocking positions as said members are closed together to enable said tumbler portions to pass through said locking apertures.

2. Locking mechanism for locking two members together, comprising:

a plurality of flexible tumblers on the other of said members, each tumbler being associated and in alignment with one of sad locking apertures, each tumbler having a portion thereof projecting through its associated locking aperture when said members are closed, which portion has a locking shoulder thereon normally hooking over the locking shoulder of the locking aperture when said tumblers are unflexed, the tumbler portions each having an over-all width less than the distance between the opposed shoulders of the associated locking aperture, said tumblers each being flexible to an unlocking position wherein the locking shoulders of said tumbler and locking aperture are out of hooked engagement, said locking apertures and tumblers being arranged so that at least two of said tumblers flex in different directions to their unlocking positions;

a key, interengageable cam means on said key and tumblers for flexing all of said tumblers simultaneously to their unlocking positions.

3. In a locking mechanism as set forth in claim 2 and further including interengageable cam surfaces on said tumblers and said one member for flexing said tumblers to their unlocking positions as said members are closed together to enable said tumbler portions to pass through said locking apertures.

4. In a locking mechanism as set forth in claim 2 wherein said interengageable cam means on said key and tumblers for flexing said tumblers to their unlocking positionscomprises said tumbler portions having a recess formed thereinto from the end of said tumbler portions, said key having unlocking prongs insertable into the recesses of said tumbler portions, said unlocking prongs and said tumbler portion recesses having interengageable cam surfaces for moving said tumblers to their unlocking positions as said unlocking prongs are inserted into said tumbler portion recesses.

5. Locking mechanism as set forth in claim 4 wherein said other of said members and the tumblers thereon comprise an integrally molded plastic member.

6. Locking mechanism for locking two members together, comprising:

one of said members having a plurality of aligning aper tures and locking apertures therethrough, said locking apertures each having a locking shoulder and another shoulder opposite thereto;

a plurality of tumblers on the other of said members, each tumbler being associated and in alignment With one of said locking apertures, each tumbler having a portion thereof projecting through its associated locking aperture when said members are closed, which portion has a locking shoulder thereon normally hooking over the locking shoulder of the locking aperture, the tumbler portions each having an overall Width less than the distance between the opposed shoulders of the associated locking aperture, said tumblers each having a flexible neck to permit flexing of said tumbler portions to an unlocking position wherein the locking shoulders of said tumbler and locking aperture are out of hooked engagement, said locking apertures and tumblers being arranged so that at least two of said tumbler portions flex in different directions to their unlocking positions;

a key having alignment prongs insertable into said alignment apertures, interengageable cam means on said key and tumbler for flexing all of said tumbler portions to their unlocking positions when said alignment prongs on said key are inserted into said alignment prongs; and

interengageable cam means on said tumbler portions and said one member for flexing said tumbler portions to their unlocking positons as said members are closed together to enable said tumbler portions to pass through said locking apertures.

7. Locking mechanism for locking two members together, comprising:

one of said members having a recess therein and a plurality of locking apertures therethrough within said recess, said locking apertures each having a locking shoulder and another shoulder opposite thereto;

a plurality of flexible tumblers on the other of said members, each tumbler being associated and in alignment with one of said locking apertures, each tumbler having a portion thereof projecting through its associated locking aperture into and completely within said recess when said members are closed, which portion has a locking shoulder thereon normally hooking over the locking shoulder of the locking aperture when said tumblers are unflexed, the tumbler portions each having an over-all width less than the distance between the opposed shoulders of the associated locking aperture, said tumblers each being flexible to an unlocking position wherein the locking shoulders of said tumbler and locking aperture are out of hooked engagement, said locking apertures and tumblers being arranged so that at least two of said tumblers flex in different directions to their unlocking positions;

a key, interengageable cam means on said key and tumblers for flexing all of said tumblers simultaneously to their unlocking positions;

8. Locking mechanism for locking two members together, comprising:

one of said members having a recess therein and a plurality of locking apertures therethrough within said recess, said locking apertures each having a locking shoulder and a shoulder opposite thereto, said one member having a plurality of aligning apertures therethrough;

a plurality of tumblers on the other of said members, each tumbler being associated and in alignment with one of said locking apertures, each tumbler having a portion thereof projecting through its associated locking aperture into and completely within said recess when said members are closed, which portion has a locking shoulder thereon normally hooking over the locking shoulder of the locking aperture, the tumbler portions each having an over-all width less than the distance between the opposed shoulders of the associated locking aperture, said tumblers each having a flexible neck to permit flexing of said tumbler portions to an unlocking position wherein the locking shoulders of said tumbler and locking aperture are out of hooked engagement, said locking apertures and tumblers being arranged so that at least tWo of said tumbler portions flex in different directions to their unlocking positions;

interengageable cam means on said tumbler portions and said one member for flexing said tumbler portions to their unlocking positions as said members are closed together to enable said tumbler portions to pass through said locking apertures.

9. In a locking mechanism as set forth in claim 8 wherein said interengageable cam means on said key and tumblers for flexing said tumblers to their unlocking positions comprises said tumbler portions having a recess formed thereinto from the end of said tumbler portions, said key having unlocking prongs insertable into the recesses of said tumbler portions, said unlocking prongs and said tumbler portion recesses having interengageable cam surfaces for moving said tumblers to their unlocking positions as said unlocking prongs are inserted into said tum bler portion recesses.

References Cited in the file of this patent UNITED STATES PATENTS 406,173 Lipe July 2, 1889 571,169 McCartney Nov. 10, 1896 2,906,579 Magnenat Sept. 29, 1959

Claims

2. LOCKING MECHANISM FOR LOCKING TWO MEMBERS TOGETHER, COMPRISING: ONE OF SAID MEMBERS HAVING A PLURALITY OF LOCKING APERTURES THERETHROUGH, SAID LOCKING APERTURES EACH HAVING A LOCKING SHOULDER AND ANOTHER SHOULDER OPPOSITE THERETO; A PLURALITY OF FLEXIBLE TUMBLERS ON THE OTHER OF SAID MEMBERS, EACH TUMBLER BEING ASSOCIATED AND IN ALIGNMENT WITH ONE OF SAD LOCKING APERTURES, EACH TUMBLER HAVING A PORTION THEREOF PROJECTING THROUGH ITS ASSOCIATED LOCKING APERTURE WHEN SAID MEMBERS ARE CLOSED, WHICH PORTION HAS A LOCKING SHOULDER THEREON NORMALLY HOOKING OVER THE LOCKING SHOULDER OF THE LOCKING APERTURE WHEN SAID TUMBLERS ARE UNFLEXED, THE TUMBLER PORTIONS EACH HAVING AN OVER-ALL WIDTH LESS THAN THE DISTANCE BETWEEN THE OPPOSED SHOULDERS OF THE ASSOCIATED LOCKING APERTURE, SAID TUMBLERS EACH