Latch assembly having pull-up action

• US 4,583,775 A
• Filed: 09/24/1985
• Issued: 04/22/1986
• Est. Priority Date: 05/16/1984
• Status: Expired due to Term

• Current Assignee: Southco Incorporated (South Chester Tube Company)
• Original Assignee: Southco Incorporated (South Chester Tube Company)
• Inventors: Bisbing, Robert H.
• Primary Examiner(s): Moore, Richard E.
• Application Number:
  US06/779,313
• Time in Patent Office: 210 Days
• Field of Search: 292/61, 292/62, 292/63, 292/64, 292/65, 292/58, 292/59, 292/68, 292/69, 292/212
• US Class Current: 292/64
• CPC Class Codes: E05B 17/0025 Devices for forcing the wing firmly against its seat or to initiate the opening of the wing E05B15/022, E05B65/0817, E05B81/20, E05C19/14 take precedence
• CPC Class Codes: E05C 3/042 the handle being at one side, the bolt at the other side or inside the wing
• CPC Class Codes: Y10T 292/0887 Operating means

Abstract

A latch of the pull-up type for a cabinet door is latched and unlatched by turning the latch in one direction or the other. When the door is in latched position, rotating the latch in the unlatching direction initially causes a spring-biased shaft, which carries a latching pawl, to move axially inwardly. This inward movement of the shaft is permitted because a sleeve cam having cam slots is moved rotationally to present inwardly sloping cam surfaces to opposite ends of a cross pin which is mounted on the shaft and which functions as a cam follower. The shaft is prevented from rotating on its own axis until the cross pin, which also functions as a motion-control pin, is moved axially inwardly a sufficient distance to escape from axial motion-control slots provided in a motion-control sleeve which is mounted coaxially on the shaft. When the motion-control pin reaches the inward ends of the axial motion-control slots, the opposite ends of the cross pin are able to move laterally into lateral motion-control slots provided in the motion-control sleeve, thereby to allow the shaft and the latch pawl to move pivotally out of the way of the cabinet frame. To latch the door, the action described takes place in reverse order.

Claims

1. A pull-up latch mechanism comprising:

a. a fixed support base having an inwardly projecting sleeve;

b. a plug-type cap within said support base and coaxial with said base sleeve;

c. a shaft having its outward end supported in said cap and having an intermediate portion supported by said base sleeve, said shaft projecting in an inward direction from said base sleeve;

d. a rotatable sleeve cam coaxial within said base sleeve, said sleeve cam having diammetrically opposed cam slots;

e. a motion-control sleeve fixed within said base sleeve and coaxial with said sleeve cam;

f. a pair of diametrically opposed axially extending motion-control slots in said motion-control sleeve;

g. a pair of diametrically opposed laterally extending motion-control slots in said motion-control sleeve;

h. each of said axial motion-control slots intersecting with one of said lateral motion-control slots at a motion translation position;

i. a cross pin secured to said shaft and extending laterally in opposite directions therefrom, each opposite end of said cross pin projecting into one of said motion-control slots and into one of said cam slots;

j. means interconnecting said cap and said sleeve cam, whereby the application of torque force to said cap moves said cam rotationally;

k. whereby, in response to said cap being moved rotationally in the same one direction, rotational and axial motions are imparted sequentially to said shaft, in that order or in reverse order depending upon the direction of rotation of said cap.

2. A pull-up latch mechanism according to claim 1 wherein a latch finger is mounted on said shaft.

3. A pull-up latch mechanism according to claim 2 wherein said fixed support base is mounted on a closure member and said base sleeve projects inwardly through an opening in said closure member.

4. A pull-up latch mechanism according to claim 3 wherein biasing means are provided for biasing said shaft in one direction for maintaining said opposite ends of said cross pin in engagement with one wall of each of said cam slots.

5. A pull-up latch mechanism according to claim 4 in which said biasing means urges said shaft in the inward unlatching direction.

6. A pull-up latch mechanism according to claim 5 in which said cap is provided with a non-circular recess for receiving the non-circular head of a torque drive tool.

7. A pull-up latch mechanism according to claim 6 in which a retainer ring is provided to prevent relative axial movement between said support base and said cap.

8. A pull-up latch mechanism according to claim 7 in which said means interconnecting said cap and said sleeve cam comprise ears projecting from one into notches in the other.

9. A pull-up latch mechanism according to claim 8 wherein said motion-control sleeve is fixed against rotation relative to said base sleeve by ears projecting from one into notches in the other.

10. A pull-up latch mechanism according to claim 8 wherein said ears project axially outwardly from said sleeve cam into notches in said cap.

11. A pull-up latch mechanism according to claim 9 wherein said ears project axially inwardly from said motion-control sleeve into notches in said base sleeve.

12. A pull-up latch mechanism according to claim 1 wherein each of said cam slots extends in a direction having both axial and circumferential components.

13. A pull-up latch according to claim 1 wherein said rotatable sleeve cam is positioned between said fixed motion-control sleeve and said support base sleeve.

14. A pull-up latch mechanism according to claim 3 in which said fixed support base has ears for receiving screws for securing said support base to said closure member.

15. A pull-up latch mechanism according to claim 3 in which said base sleeve is externally threaded and is secured to said closure member by a nut screwed onto said base sleeve.

16. A pull-up latch mechanism comprising:

a. a fixed motion-control sleeve having in its wall a pair of diametrically opposed axially extending slots and a pair of diametrically opposed laterally extending slots, each of said axial slots intersecting with one of said lateral slots at a motion translation position;

b. a rotatable cam sleeve coaxial and coextensive with at least a portion of said motion-control sleeve, said cam sleeve having diametrically opposed cam slots each of which extends in a direction having both axial and circumferential components;

c. a shaft coaxial within said sleeves, said shaft projecting therefrom in one axial direction;

d. a cross pin mounted in said shaft and extending laterally in opposite directions therefrom, and projecting into each of said cam slots and into each of said motion-control slots; and

e. means for applying a torque force to said cam sleeve for moving said cam sleeve rotationally, whereby, in response to said cam sleeve being moved rotationally in the same one direction, rotational and axial motions are imparted sequentially to said shaft, in that order or in reverse order depending upon the direction of rotation of said cam sleeve.

17. A pull-up latch mechanism acording to claim 16 wherein a latch finger is mounted on said shaft.

18. A pull-up latch mechanism according to claim 17 wherein said means for applying a torque force to said cam sleeve includes a plug type cap coaxial with said cam sleeve and means connecting said cap to said cam sleeve.

19. A pull-up latch mechanism according to claim 18 in which said cap is provided with a recess for receiving the head of a torque drive tool.

20. A pull-up latch mechanism according to claim 19 wherein biasing means are provided for biasing said shaft in one direction for maintaining opposite ends of said cross pin in engagement with a wall of each of said cam slots.