Quick cam latch mechanism

• US 20070007773A1
• Filed: 07/08/2005
• Published: 01/11/2007
• Est. Priority Date: 07/08/2005
• Status: Active Grant

• Current Assignee: Hardware Specialties, Inc.
• Original Assignee: Hardware Specialties, Inc.
• Inventors: Berkseth, John, Kondratuk, Michael
• Granted Patent: US 7,703,815 B2
• Time in Patent Office: Days
• US Class Current: 292/169
• CPC Class Codes: E05B 53/00 Operation or control of locks by mechanical transmissions, e.g. from a distance
• CPC Class Codes: E05C 1/16 the handle or member moving essentially in a plane substantially parallel to the wing or frame
• CPC Class Codes: Y10T 292/097 Operating means
• CPC Class Codes: Y10T 292/0971 Cam and lever
• CPC Class Codes: Y10T 292/0977 Cam

Abstract

A quick cam latch mechanism having an operatively coupled bolt and cam assembly disposed in a latch housing. A handle is coupled to the cam assembly for moving the bolt between an extended or engaged position and a retracted or disengaged position. The cam assembly includes a primary cam operatively coupled to a secondary cam or linkage that is in turn operatively coupled to the bolt. Rotation of the primary cam translates into increased pivoting of the linkage and thereby increased retraction of the bolt. As a result, less rotation of primary cam is needed to retract the bolt. In an example embodiment of the invention, at least two linkages are utilized to quickly retract the bolt regardless of the direction of rotation of the handle.

Claims

1. A quick cam latch mechanism comprising:

a housing;

a bolt disposed in the housing, the bolt being positionable between an extended position and a retracted position; and

a cam assembly disposed in the housing and operatively coupled to the bolt, the cam assembly having at least one rotatable primary cam that is in operative contact with at least one pivotal linkage adapted to pivot at a rate generally greater than a rate of rotation of the primary cam, the linkage being operatively coupled to the bolt, wherein rotation of the primary cam directly pivots the at least one linkage which in turn translates into linear retraction of the bolt from the extended position toward the retracted position.

2. The latch assembly of claim 1, further comprising a handle operatively coupled to the primary cam to actuate the cam assembly and retract the bolt into the housing.

3. The latch assembly of claim 1, wherein the cam assembly further comprises at least one biasing member disposed in the housing and operatively confronting at least a portion of the bolt, wherein the biasing member moves the bolt from the retracted position toward the extended position.

4. The latch assembly of claim 3, wherein the biasing member comprises a coiled spring.

5. The latch assembly of claim 1, wherein the bolt comprises a body portion and a pair of spaced leg portions extending away therefrom, the at least one linkage operatively confronting at least one of the leg portions.

6. The latch assembly of claim 5, wherein the leg portion includes a linkage notch formed therein, the at least one linkage being selectively engaged with the linkage notch.

7. The latch assembly of claim 5, wherein the leg portion includes a linkage notch formed therein, the at least one linkage being continuously engaged with the linkage notch.

8. The latch assembly of claim 1, wherein the at least one linkage has an undulating peripheral edge defining a flared portion, wherein engagement between the primary cam and the flared portion of the linkage increases the rate of pivoting of the linkage and thus increases the rate retraction of the bolt.

9. The latch assembly of claim 8, wherein the primary cam has an arm portion having a pair of opposed protuberances that engage the peripheral edge of the at least one linkage.

10. The latch assembly of claim 8, wherein the at least one linkage has a post portion extending away therefrom pivotally coupling it to a portion of the housing.

11. The latch assembly of claim 8, wherein the at least one linkage has a peg portion extending away therefrom and extending into and operatively confronting a linkage notch formed in a portion of the bolt.

12. The latch assembly of claim 1, wherein the cam assembly comprises a pair of linkages, the pair of linkages being operatively disposed on opposed sides of the primary cam such that rotation of the primary cam in opposed directions causes engagement of the primary cam with either of the linkages.

13. A latch assembly comprising:

a housing and a cover defining an interior of the housing;

a bolt slidably disposed in the interior of the housing, the bolt being positionable between an extended position and a retracted position;

a first linkage pivotally coupled to a portion of the housing to engage at least a portion of the bolt, the first linkage having a flared portion defining an undulating peripheral edge;

a second linkage pivotally coupled to a portion of the cover to engage at least a portion of the bolt, the second linkage having a flared portion defining an undulating peripheral edge;

a primary cam rotationally disposed at least partially between the first and second linkages, rotation of the primary cam in a first direction causes it to engage at least a portion of the first linkage, rotation of the primary cam in a second direction causes it to engage at least a portion of the second linkage;

a handle rotatably coupled to the primary cam to rotate the primary cam in the first and second directions; and

wherein upon rotation of the primary cam in either of the first and second directions, a portion of the primary cam engages the flared portion of at least one of the first and second linkages creating a rotational differentiation between a rate of rotation of the primary cam and a rate of pivoting of the linkages such that the rate of pivoting of the first and second linkages is generally greater than a rate of rotation of the primary cam, whereby the increased rate of pivoting of the linkages translates into an increased linear retraction of the bolt.

14. The latch assembly of claim 13, further comprising a biasing member disposed between the bolt and a portion of the housing to bias the bolt from the retracted position toward the extended position.

15. The latch assembly of claim 13, wherein the bolt has a body portion and a pair of spaced leg portions extending away therefrom, the first and second linkages operatively coupling the leg portions.

16. The latch assembly of claim 15, wherein each of the spaced leg portions includes linkage notch extending therein for receiving a portion of the first and second linkages.

17. The latch assembly of claim 16, wherein the first and second linkages each have a peg portion for engaging the linkage notch of the spaced apart leg portions.

18. The latch assembly of claim 13, wherein the first linkage has a post extending away therefrom that is pivotally coupled to a portion of the housing, and the second linkage has a post extending away therefrom that is pivotally coupled to a portion of the cover.

19. A method of increasing latch retraction, comprising the steps of:

disposing a bolt in an interior of a latch housing, the bolt being positionable between an extended position and a retracted position;

coupling a pivotable first linkage to a portion of the housing to engage at least a portion of the bolt, the first linkage having a flared portion defining an undulating peripheral edge;

coupling a rotatable primary cam at least partially adjacent to the first linkage, rotation of the primary cam in a first direction causes it to engage at least a portion of the undulating peripheral edge of the first linkage;

operatively coupling a handle to the primary cam for rotating the primary cam in at least a first direction; and

wherein rotational engagement of the primary cam with the flared portion of the first linkage creates a rotational differentiation between a rate of rotation of the primary cam and a rate of pivoting of the first linkage such that the rate of pivoting of the first linkage is generally greater than a rate of rotation of the primary cam, whereby the increased rate of pivoting of the first linkage translates into an increased linear retraction of the bolt.

20. The method of increasing latch retraction of claim 19, further comprising the step of coupling a pivotable second linkage to a portion of the housing to engage at least a portion of the bolt, the second linkage having a flared portion defining an undulating peripheral edge, wherein rotation of the primary cam in a second direction causes it to engage the flared portion of the second linkage creating a rotational differentiation between a rate of rotation of the primary cam and a rate of pivoting of the second linkage such that the rate of pivoting of the second linkage is generally greater than a rate of rotation of the primary cam, whereby the increased rate of pivoting of the first linkage translates into increased linear retraction of the bolt.

21. The method of increasing latch retraction of claim 20, further comprising the step of positioning the primary cam generally between the first and second linkages.

22. The method of increasing latch retraction of claim 19, further comprising forming a peg on the first linkage that extends into and engages a linkage notch extending into a portion of the bolt.

23. The method of increasing latch retraction of claim 22, wherein the bolt has a body portion and a pair of leg portions with the linkage notch extending into at least a portion of at least one of the leg portions.

24. The method of increasing latch retraction of claim 23, wherein the peg is in continuous engagement with the linkage notch.

25. The method of increasing latch retraction of claim 19, further comprising the step of forming at least one depression in an inner surface of the housing to prevent interferences between the first linkage and the housing.

26. The method of increasing latch retraction of claim 19, further comprising the step of providing at least one stop extending away from the bolt to engage at least a portion of the housing, wherein the stop selectively engages a portion of the housing to limit a maximum extended position of the bolt out of the housing.

27. The method of increasing latch retraction of claim 26, wherein the stop selectively engages a portion of the housing to limit a maximum retracted position of the bolt in the housing.

28. The method of increasing latch retraction of claim 19, further comprising the step of operatively coupling a biasing means to the bolt to move the bolt from the retracted position toward the extended position.