Cabinet earthquake latch assembly

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, in general, to cabinet latches and, in particular, to cabinet earthquake latches.

2. Description of the Related Art

During an earthquake, the doors of cabinets are frequently jolted open and the cabinet contents (e.g., jars, glassware, china and cans) consequently ejected, causing damages to the contents and/or injury to persons. Standard cabinet latches offer little protection from such damage or injury since the forces generated during an earthquake often overcome (i.e., release) a standard cabinet latch.

Over the years, cabinet earthquake latches that employ various combinations of levers, springs and pushbuttons have been developed, in response to the forgoing problem. These conventional cabinet earthquake latches are configured such that the forces generated during an earthquake are not able to release the latch. Conventional cabinet earthquake latches can, however, be released using a specific operating procedure. Since release requires a specific operating procedure, such conventional cabinet earthquake latches also function as child safety cabinet latches.

Conventional cabinet earthquake latches, however, suffer from several drawbacks. Many require more than one hand to operate. For example, a specific operating procedure may require that one hand be used to press a pushbutton or move a lever, while the other hand is opening the cabinet door. As a consequence, a user is precluded from performing routine tasks, such as opening a cabinet door with one hand while placing contents held in the other hand into the cabinet. Conventional cabinet earthquake latches are also often visible from outside of the cabinet, resulting in an unattractive appearance. Furthermore, frequently conventional cabinet earthquake latches are functional with only certain configurations of cabinets (e.g., cabinets with inner lips of a predetermined size).

Still needed in the field, therefore, is a cabinet earthquake latch that can be operated with one hand, is functional with a wide variety of cabinet configurations and is not visible from outside of the cabinet.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a cabinet earthquake latch assembly designed to be attached on an inner surface of a cabinet (hereinafter referred to as a “cabinet inner surface”) and a back surface of a cabinet door, thereby making it invisible from outside of the cabinet. The cabinet earthquake latch assembly can be operated with one hand and is functional with a wide variety of cabinet configurations.

One exemplary embodiment of the present invention includes a door arm, a cam and a strike. When the cabinet earthquake latch assembly is in use, the door arm is attached to a back surface of the cabinet door, the cam is rotatably attached to the door arm and the strike is attached to the cabinet inner surface.

The cam and strike are configured and attached to the door arm and cabinet inner surface such that the cam collides with the strike when the cabinet door is being initially opened at at least a predetermined speed (e.g., a cabinet door speed that would result from forces generated in an earthquake that are strong enough to cause movement of cabinet contents). This collision causes rotation of the cam from a rest position. The cam then becomes lodged against the strike in a rotated position, thus preventing further opening of the cabinet door. However, when the cabinet door is initially opened at less than the predetermined speed, the cam collides with the strike and is rotated from the rest position. But, the cam then rotates back towards the rest position and, thereafter, clears the strike during further opening of the cabinet door.

The rotational response of the cam to the speed, at which the cabinet door is opened, determines whether the cam will become lodged against the strike (and thus prevent further opening of the cabinet door) or clear the strike (and thus allow further opening of the cabinet door). When the cabinet door is opened at at least a predetermined speed (i.e., opened quickly), the cam is rotated from a rest position by its collision with the strike and becomes lodged against the strike before it is able to return to the rest position. However, when the door is opened at less than the predetermined speed (i.e., opened slowly), the cam is rotated by its collision with the strike but then is able to return to the rest position and clear the strike. Whether or not the cam becomes lodged against the strike or clears the strike is, therefore, a function of the speed at which the door is opened.

Since the operation of earthquake cabinet latch assemblies according to the present invention is based on the rotational response of the cam, they can be operated with only one hand (or even one finger). In addition, since the door arm can be attached to the cabinet inner surface and a back surface of the cabinet door, earthquake cabinet latch assemblies of the present invention are not visible from outside of the cabinet and can be used with a wide variety of cabinet configurations.

A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C

are top, side and cross-sectional end views, respectively, of a door arm of a cabinet earthquake latch assembly according to one exemplary embodiment of the present invention.

FIG. 2

is a side view of a cam of a cabinet earthquake latch assembly in accordance with one exemplary embodiment of the present invention.

FIGS. 3A-3C

are cross-sectional side, front and bottom views, respectively, of a strike of a cabinet earthquake latch assembly according to one exemplary embodiment of the present invention.

FIG. 4

is a side view of a cabinet earthquake latch assembly according to one exemplary embodiment of the present invention with the cam rotatably attached to the door arm, the door arm attached to a back surface of a cabinet door and the strike attached to a cabinet inner surface. In

FIG. 4

, the cam is at a rest position with the cabinet door closed.

FIG. 5

is a side view of a cabinet earthquake latch assembly according to the present invention with the cam rotatably attached to the door arm, the door arm attached to a back surface of a cabinet door and the strike attached to a cabinet inner surface. In

FIG. 5

, the cabinet door is being opened and the cam is just colliding with the strike.

FIG. 6

is a side view of a cabinet earthquake latch assembly according to one exemplary embodiment of the present invention with the cam rotatably attached to the door arm, the door arm attached to a back surface of a cabinet door and the strike attached to a cabinet inner surface. In

FIG. 6

, the cabinet door has been initially opened such that the cam is rotated from a rest position.

FIG. 7

is a side view of a cabinet earthquake latch assembly according to one exemplary embodiment of the present invention with the cam rotatably attached to the door arm, the door arm attached to a back surface of a cabinet door (not shown in

FIG. 7

) and the strike attached to a cabinet inner surface. In

FIG. 7

, the cam is lodged against the strike.

FIG. 8

is a side view of a cabinet earthquake latch assembly according to the one exemplary embodiment of the present invention with the cam rotatably attached to the door arm, the door arm attached to a back surface of a cabinet door and the strike attached to a cabinet inner surface. In

FIG. 8

, the cam has returned to the rest position and is thus able to clear the strike as the cabinet door is further opened.

DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

FIGS. 1A-4

are illustrations of one exemplary embodiment of a cabinet earthquake latch assembly

10

for use on a cabinet with a cabinet inner surface (labeled I in

FIG. 4

) and a back surface of a cabinet door (labeled D in FIG.

4

). Cabinet earthquake latch assembly

10

includes a door arm

12

, a cam

14

and a strike

16

. Door arm

12

, cam

14

and strike

16

can be formed, for example, of injection molded plastic and are, therefore, relatively inexpensive to manufacture.

FIGS. 1A-1C

are top, side and cross-sectional end views, respectively, of door arm

12

, which is configured for attachment at a suitable attachment location on the back surface of cabinet door D when cabinet earthquake latch assembly

10

is in use. Door arm

12

can be attached to the back surface of the cabinet door D using screws (not shown) inserted through door arm openings

18

and

20

included in door arm

12

, as illustrated in FIG.

1

C. Door arm

12

includes a cam stop portion

22

, the function of which is explained below.

Cam

14

is configured to be rotatably attached to door arm

12

when cabinet earthquake latch assembly

10

is in use, as illustrated in FIG.

4

. Cam

14

is rotatably attached to door arm

12

at a pivot point of the cam (labeled P in

FIG. 4

) that is offset from the center of gravity of cam

14

. Cam

14

is, therefore, attached to door arm

12

in a manner that allows cam

14

to rotate about pivot point P. However, cam stop portion

22

of door arm

12

serves to limit gravity-induced rotation of cam

14

and to define the rest position of cam

14

, as shown in FIG.

4

. Cam

14

can be attached to door arm

12

using, for example, a screw placed in countersunk opening

23

.

Cam

14

also includes a cam opening

24

, a convex cam lower surface

26

, a concave cam lower surface

28

and a flat upper surface

30

. When cam

14

is in the rest position, flat upper surface

30

abuts cam stop portion

22

, as illustrated in FIG.

4

.

FIG. 4

depicts cabinet earthquake latch assembly

10

in use with the back surface of the cabinet door D in a closed position. Therefore, in

FIG. 4

, cam

14

is in a rest position determined by (i) gravity, (ii) pivot point P being off-set from the center of gravity of cam

14

and (iii) cam stop portion

22

.

Cam

14

can have an overall length L of 1.025 inches, a height H in the rest position 0.525 inches and a thickness of 0.25 inches (see

FIG. 2

, where the dimensions L and H are marked). Furthermore, convex cam lower surface

26

can have a 1.00 inch radius of curvature and concave cam lower surface

28

can have a 0.150 inch radius of curvature.

Strike

16

is configured for attachment to cabinet inner surface I when cabinet earthquake latch assembly

10

is in use. Strike

16

includes a skid portion

32

and a locking portion

34

. Strike

16

can be attached to cabinet inner surface I using screws (not shown) inserted through strike openings

36

and

38

provided in strike

16

, as illustrated in

FIGS. 3B and 3C

.

Strike

16

also includes an alignment opening

40

that extends partially through strike

16

, as shown in

FIGS. 3A and 3B

. Alignment opening

40

is positioned in strike

16

such that when strike

16

is attached to cabinet inner surface I and cabinet door D is closed, alignment opening

40

is aligned with a suitable attachment location on the back surface of cabinet door D for door arm

12

.

As is well known to one skilled in the art, cabinets can be configured with either left-handed or right-handed hinge positions. Door arm

12

, cam

14

and strike

16

are configured to possess left and right-handed symmetry in order that cabinet earthquake latch assembly

10

can be used on a cabinet with either left-handed or right-handed hinges. This left and right-handed symmetry enables the cabinet earthquake latch assembly to function on a cabinet regardless of hinge position.

FIG. 5

depicts cabinet earthquake latch assembly

10

when cabinet door D is in the process of being initially opened (i.e., being opened only a small distance, for example, less than 0.125 inches). Regardless of the speed at which cabinet door D is opened, cam

14

and strike

16

are configured and attached to door arm

12

and cabinet inner surface I, respectively, such that convex cam lower surface

26

of cam

14

collides with skid portion

32

of strike

16

.

Since cam

14

is rotatably attached to door arm

12

, convex cam lower surface

26

rides along skid portion

32

and cam

14

rotates in a counter-clockwise direction from the rest position as cabinet door D is initially opened. Convex cam lower surface

26

is curved to facilitate such a rotation of cam

14

. The force of the collision also serves to induce a rotating motion in cam

14

that is maintained even after convex cam lower surface

26

is no longer in contact with skid portion

32

, as illustrated in FIG.

6

.

In the circumstance that cabinet door D is being opened at at least a predetermined speed (i.e., at a relatively high speed that is equal to or greater than a speed induced on the cabinet door by forces generated in an earthquake that are strong enough to cause movement of cabinet contents), cam opening

24

is sufficiently rotated to become lodged (i.e., latched) against locking portion

34

of strike

16

with cam

14

in a rotated position (see FIG.

7

). Since cam opening

24

is lodged against locking portion

34

, further opening of cabinet door D is prevented. Since the cabinet door is prevented from opening fully, damage to cabinet contents or persons due to ejection of the cabinet contents is barred.

When cam opening

24

is lodged against locking portion

34

, cabinet door D will be open to a slight extent. The extent to which cabinet door D is open depends on the width of cabinet door D and the distance between the cabinet earthquake latch assembly and the hinges of cabinet door D. However, a typical distance that cabinet door D will be open is only in the range of 1.00 inches to 1.50 inches.

In the circumstance where cabinet door D is opened at less than the predetermined speed (i.e., at a speed that is less than a speed induced on the cabinet door by forces generated in an earthquake that are strong enough to cause movement of cabinet contents), convex cam lower surface

26

of cam

14

will collide with skid portion

32

of strike

16

, as depicted in FIG.

5

. Furthermore, this collision will result in cam

14

being rotated from the rest position (see FIG.

6

). However, since cabinet door D is being opened at less than the predetermined speed (i.e., being opened slowly), cam

14

is able to return to the rest position (by rotating under the influence of gravity) without becoming lodging against strike

16

, as shown in FIG.

8

. Cam

14

is, thereafter, able to clear strike

16

during further opening of cabinet door. D In this regard, the vertical distance between skid portion

32

and locking portion

34

is predetermined such that cam

14

can pass between the skid portion and the locking portion when cabinet door D is opened at less than the predetermined speed.

When cabinet earthquake latch assembly

10

is in use, a user can fully open cabinet door D with one hand (or even one finger) by merely pulling cabinet door D open at a speed that is less than the predetermined speed. However, should cabinet door D be jolted open during an earthquake at a speed that is equal to or greater than the predetermined speed, cabinet earthquake latch assembly

10

will prevent cabinet door D from opening more than a slight extent.

When cabinet door D is being closed from a fully open position, concave cam lower surface

28

is configured to collide with skid portion

32

and facilitate rotation of cam

14

, thus allowing cabinet door D to fully close.

Alignment opening

40

of strike

16

is configured to contain a nail such that the nail protrudes from alignment opening

40

. Alignment opening

40

can, therefore, aid in the proper attachment of door arm

12

to cabinet door D in the following manner. Strike

16

is first attached to cabinet inner surface I. A nail is then placed in alignment opening

40

such that the pointed end of the nail is slightly protruding from alignment opening

40

and the head of the nail is abutted against strike

16

. Cabinet door D is then forcibly closed. The pointed end of the nail will have marked a suitable attachment location on the back surface of cabinet door D for door arm

12

.

It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. For example, the configuration (e.g., shape) and attachment of the cam, strike and door arm can be altered from that described herein. It is intended that the following claims define the scope of the invention and that structures within the scope of these claims and their equivalents be covered thereby.