Cabinet earthquake latch assembly

Information

  • Patent Grant
  • 6619706
  • Patent Number
    6,619,706
  • Date Filed
    Tuesday, August 7, 2001
    23 years ago
  • Date Issued
    Tuesday, September 16, 2003
    21 years ago
  • Inventors
  • Original Assignees
  • Examiners
    • Miller; William
    • Lugo; Carlos
    Agents
    • Townsend and Townsend and Crew LLP
Abstract
A cabinet earthquake latch assembly designed to be attached on a cabinet inner surface and a back surface of a cabinet door. The cabinet earthquake latch assembly includes a door arm, a cam and a strike. When in use, the door arm is attached to 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 speed generated in an earthquake). This collision causes the cam to rotate from a rest position and then to become lodged against the strike in a rotated position, thus preventing further opening of the cabinet door.
Description




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.



Claims
  • 1. A cabinet earthquake latch assembly for use on a cabinet comprising:a door arm configured for attachment to a back surface of a cabinet door; a cam configured for rotatable attachment to the door arm, the cam comprising: a cam opening; and a convex cam lower surface; a strike configured for attachment to an inner surface of the cabinet, the strike comprising: a skid portion; and a locking portion; wherein the cam collides with the strike when the cabinet door is being initially opened at at least a predetermined speed, thereby causing rotation of the cam from a rest position, the cam thereafter becoming lodged against the strike in a rotated position, thus preventing further opening of the cabinet door, wherein the cam collides with the strike when the cabinet door is initially opened at less than the predetermined speed, thereby causing rotation of the cam from the rest position, the cam thereafter clearing the strike during further opening of the cabinet door, and wherein the convex cam lower surface collides with the skid portion when the cabinet door is being initially opened at at least a predetermined speed thereby causing rotation of the cam from the rest position, the cam opening thereafter becoming lodged against the locking portion with the cam in a rotated position, thus preventing further opening of the cabinet door.
  • 2. The cabinet earthquake latch assembly of claim 1, wherein the cam collides with the skid portion when the cabinet door is being initially opened at at least a predetermined speed thereby causing rotation of the cam from the rest position, the cam thereafter becoming lodged against the locking portion in a rotated position, thus preventing further opening of the cabinet door.
  • 3. The cabinet earthquake latch assembly of claim 2, wherein the cam collides with the skid portion when the cabinet door is opened at less than the predetermined speed thereby causing rotation of the cam from the rest position, the cam thereafter clearing the strike during further opening of the cabinet door by passing between the skid portion and the locking portion.
  • 4. The cabinet earthquake latch assembly of claim 1, wherein the cam further includes:a concave cam lower surface; wherein the concave cam lower surface collides with the skid portion when the cabinet door is being closed thereby causing rotation of the cam.
  • 5. The cabinet earthquake latch assembly of claim 1, wherein the door arm is attached to a suitable attachment location on the back surface of the cabinet door, andwherein the strike includes an alignment opening partially therethrough, and wherein the alignment opening is positioned in the strike such that when the strike is attached to the cabinet inner surface and the cabinet door is closed, the alignment opening is aligned with the suitable attachment location of the door arm.
  • 6. The cabinet earthquake latch assembly of claim 5, wherein the alignment opening is configured to contain a nail such that the nail protrudes from the alignment opening.
  • 7. The cabinet earthquake latch assembly of claim 1, wherein the cam is rotatably attached to the door arm at a pivot point of the cam that is offset from a center of gravity of the cam.
  • 8. The cabinet earthquake latch assembly of claim 7, wherein the door arm includes a cam stop portion configured to limit rotation of the cam and thereby define the rest position of the cam.
  • 9. The cabinet earthquake latch assembly of claim 1, wherein the strike includes:a skid portion; and a locking portion; wherein the skid portion and the locking portion are spaced apart by a distance sufficient to provide clearance for the cam to pass therebetween when the cam is in the rest position.
  • 10. The cabinet earthquake latch assembly of claim 1, wherein the predetermined speed is a speed that is induced on the cabinet door by forces generated in an earthquake that are strong enough to cause movement of cabinet contents.
  • 11. The cabinet earthquake latch assembly of claim 1, wherein the door arm, strike and cam are each have left and right-handed symmetry.
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