Push To Release Latch Friction Type

Abstract

A push release latch particularly adapted for use on appliance cabinets and the like having first and second members movable toward each other to a closed position and away from each other to an open position, is provided comprising a first latch element carried by the first member, and a second latch element carried by the second member. At least one of the latch elements is adapted for rotation relative to the other latch element between a latched position and an unlatched position. At least one of the latch elements has a cam means associated therewith for rotating at least one of the latch elements toward the unlatched position when the members are moved toward each other from the closed position. By this arrangement, the members may be released by the latch from the closed position by moving the members toward each other from the closed position.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to push release latches and, more particularly, to a push-to-release latch for a closure which may be unlatched by pushing the closure beyond the normally closed position.

It is desirable in many cabinet applications, such as automatic clothes dryer cabinets, to provide the cabinet closure with a latch mechanism which may be readily opened by an operator whose hands are occupied with clothes or other materials. A variety of push-to-release latch arrangements have been proposed by the prior art for this purpose. However, most of these devices are of a complex design employing a multiplicity of intricate latch mounting and operation parts. A number of these devices further make no provision for the problem of overclosure which occurs when the closure is forced into a latching configuration with sufficient force to cause the latch to go over center, whereupon the closure is, in the same operation, both latched and unlatched leaving it free to be moved to the open position.

It is accordingly an object of the present invention to provide a push-to-release latch of simple construction which is easy to operate and which will releasably retain the closure in a latched configuration despite any overclosure action which may occur in latching.

It is a further object of my invention to provide such a push-to-release latch which is well suited for service on appliance and other cabinets.

SUMMARY OF THE INVENTION

Briefly stated, in accordance with one aspect of the present invention, there is provided a push release latch for first and second members movable toward each to a closed position and away from each other to an open position. The latch comprises a first latch element carried by the first member and a second latch element carried by the second member. At least one of the latch elements is adapted for rotation relative to the other latch element between a latched position and an unlatched position. At least one of the latch elements has a cam means associated therewith rotating at least one of the latch elements toward the unlatched position when the members are moved toward each other from the closed position. By this arrangement, the members may be released by the latch from the closed position by moving the members toward each other from the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention will be better understood from the following description of the preferred embodiment taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a clothes dryer incorporating the preferred embodiment of the present invention;

FIG. 2 is a fragmentary perspective view illustrating portions of both latch elements of my invention in a normally closed configuration;

FIG. 3 is a fragmentary perspective view illustrating certain details of the first latch element of my invention in a latched configuration;

FIG. 4 is a rear elevational view of the first latch element in the configuration of FIG. 3;

FIG. 5 is a bottom view of the first latch element of FIG. 4 and of the second latch element in engagement therewith;

FIG. 6 is a sectional view taken along line 6--6 of FIG. 5;

FIG. 7 is a fragmentary perspective view similar to FIG. 2 of the first latch element of my invention in the unlatched position;

FIG. 8 is a fragmentary perspective view illustrating the first latch element with its follower engaging a first stop;

FIG. 9 is a rear elevational view similar to FIG. 4 illustrating the first latch element in the configuration of FIG. 8;

FIG. 10 is a bottom view of the first latch element of FIG. 9 and of the second latch element in engagement therewith;

FIG. 11 is a sectional view taken along line 11--11 of FIG. 10;

FIG. 12 is a fragmentary perspective view similar to FIG. 8 illustrating the first latch element in a latched position with the follower positioned for a subsequent rotation to the unlatched position;

FIG. 13 is a fragmentary perspective view similar to FIG. 12 illustrating the first latch element in the unlatched position with the follower engaging a second stop;

FIG. 14 is a rear elevational view of the first latch element in the configuration of FIG. 13;

FIG. 15 is a bottom view of the first latch element of FIG. 14 and the second latch element in engagement therewith; and

FIG. 16 is a fragmentary perspective view similar to FIG. 13 illustrating the first latch element in a transition step between the unlatched position of FIG. 13 and the latched position of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, and initially to FIG. 1 thereof, there is illustrated an automatic clothes dryer 10 having a tumbling basket 11 arranged for rotation about the horizontal axis. The basket 11 is mounted within an outer cabinet 12, and a door or closure 13 is provided on the cabinet for access to the interior of the basket. During the operation of the machine 10 warm dry air is blown into the basket 11 through an opening 14 in a rear bulkhead closing the back of the basket. After passing through the basket and extracting moisture from the clothes therein, this air is then discharged into an exhaust opening 15 through a passageway 16 in the door 13. It will be understood that the dryer is provided with suitable air moving and heater means for creating this flow of warm dry air.

Door 13 may comprise an assembly of an outer door panel 17 and an inner door panel or first member 18 secured together with appropriate fasteners (not shown). The door 13 is hinged along a vertical axis by means of hinges 19 secured to inner door panel or first member 18 and to a front cabinet panel or second member 20. To facilitate continuity in describing my invention in conjunction with later figures in which only the first member 18 of door 13 is illustrated, it should be understood that reference to movement of first member 18 necessarily implies integral movement of door 13, of which first member 18 is a part. Member 18 is movable toward member 20 to a closed position and away from member 20 to the open position of FIG. 1. In order to hold the door 13 in the closed position during operation of the dryer 10, a push release latch is provided comprising a first latch element 21 carried by first member 18 and a second latch element 22 carried by the second member 20.

As will be explained in detail in conjunction with later figures, at least one of the latch elements 21 and 22 is adapted for rotation relative to the other latch element between a latched position and an unlatched position. Furthermore, at least one of the latch elements 21 and 22 has a cam means associated therewith for rotating at least one of the latch elements toward the unlatched position when members 18 and 20 are moved toward each other from the closed position. By this arrangement, members 18 and 20 may be released by the latch from the closed position by moving the members 18 and 20 toward each other from the closed position.

To provide a clearer understanding of the structure and operation of my latch, reference is made to FIG. 2 which illustrates members 18 and 20 in the closed position and latch elements 21 and 22 in the latched position. The first latch element 21 includes a strike 23 which projects from member 18. The second latch element 22 includes a catch spring 24 secured within a cavity 25 defined by wall 26 and other walls (not shown) which are integral with second member 20. Catch spring 24 is substantially C-shaped, the outer legs of which converge to produce a restricted opening 27 and then diverge to produce a smooth entrance to the restricted opening 27.

Strike 23 comprises a thin circular portion 28 disposed adjacent to and parallel with first member 18 and a projecting portion 29 which extends from the circular portion 28 in a plane perpendicular thereto. Projecting portion 29 narrows from a region 30 of relatively large cross-sectional area to a region 31 of constant, relatively small cross-sectional area. From region 31, projecting portion 29 widens to form an enlarged sector 32 and terminates forming a blunt-pointed or rounded tip 33.

As is readily apparent, the strike 23, and particularly the projecting portion 29 thereof is of complex configuration. Each of the various formations thereon has a specific purpose. Blunt-pointed or rounded end 33 enables the projection of enlarged sector 32 through restricted opening 27 when door 13 moves from the open position of FIG. 1 to the closed position of FIG. 2. Enlarged sector 32 cooperates with restricted opening 27 to hold door 13 in the closed position. Although restricted opening 27 is smaller than enlarged sector 32 and will thereby normally serve to hold strike 23 in the latched position, should a child be trapped within the dryer 10, an outward force on door 13 from the interior of the cabinet 12 will cause strike 23 to disengage catch spring 24 permitting door 13 to be moved to the open position. It should be understood, however, that this method of unlatching, wherein strike 23 is forcefully withdrawn from catch spring 24, is not the normal mode of unlatching movement, but is provided as a safety precaution.

As will be explained in greater detail in conjunction with later figures, normal unlatching is accomplished by causing strike 23 to rotate, thereby aligning the plane of projecting portion 29 with restricted opening 27 whereby the projecting portion 29 and enlarged sector 32 no longer restrictively engage catch spring 24 and may be withdrawn therefrom with minimal force. To provide for such strike rotation, cam surfaces 34 and 35 are formed between regions 30 and 31 on strike 23. Cam surfaces 34 and 35 are inclined from the plane of projecting portion 29 and are adapted to cooperate with restricted opening 27 such that when members 18 and 20 are moved toward each other from the closed position, strike 23 is caused to rotate in the direction of arrow 36 toward the unlatched position.

The portion of the first latch element 21 illustrated in FIG. 2 is only that portion which projects from first member 18. In order to support strike 23 for rotation, a shaft portion 37 of strike 23 extends through an opening in first member 18 and into the inner door chamber defined by the inner and outer door panels 17 and 18 as shown in FIG. 3. Associated with shaft portion 37 is a rotation control means 38 which is adapted to require a specific sequence of strike rotation before the strike 23 may assume the unlatched position. Such rotation control means is desirable in order to provide for the problem of "overclosure" which may occur when member 18 is moved toward member 20 with such closure force as to cause enlarged sector 32 to project through restricted opening 27 and also to cause cam surfaces 34 and 35 to engage the catch spring whereupon strike 23 is rotated toward the unlatched position. Such "overclosure," unless provided for with specific strike rotation control means, may result in the door 13 latching and unlatching in the same closure movement.

Rotation control means 38 operates to require rotation of strike 23 in the direction of arrow 36 to a position intermediate the latched and unlatched positions, and a return rotation to the latched position before the strike 23 is released by the rotation control means for subsequent rotation to the unlatched position. By such an arrangement, should overclosure occur, rotation control means 38 will permit rotation of strike 23 only so far as the intermediate position, and will require a return rotation to the latched position before the door may be opened. A subsequent movement of member 18 toward member 20 is then required to rotate the strike to the unlatched position thereby releasing the door 13 for movement to the open position.

Rotation control means 38, as seen in FIG. 3, comprises an arm 39 secured to shaft portion 37 for rotation therewith, a first cam 40 carried by the arm 39, and a second cam 41 supported from the first member 18. A cam follower 42 is pivotally mounted about shaft portion 37 at one end 43 thereof and is engageable with first and second stops 45 and 46 at the other end 44 thereof. Intermediate its ends, 43 and 44, cam follower 42 rests on first cam 40 between end surfaces 47 and 48. Resilient means comprising a compression coil spring 49 operates between a spring slip 50 secured to shaft portion 37 and the end 43 of follower 42, to bias follower 42 toward arm 39. This resilient mounting of follower 42 permits its movement along cam surface 40 from a first position engaging end surface 47 to a second position engaging end surface 48.

A biasing means is preferably provided to bias strike 23 toward its latched position. Such biasing means may comprise a torsion spring or the like, but is shown in FIG. 3 as comprising a weight 51 secured to arm 39 and positioned relative to shaft portion 37 so as to exert a torque in the opposite direction of arrow 36. The rotation of arm 39 in the direction opposite arrow 36 by weight 51 is limited by a stop 52 secured to first member 18.

In an analogous fashion to the operation of stop 52 which limits the rotation of arm 39 in one direction, rotation control means 38 operates to provide two alternatively operable stops 45 and 46 to limit the rotation of arm 39 in the other direction. To understand the operation of stops 45 and 46, it is important to understand the relative positions of "heights" of cams 40 and 41, stops 45 and 46, and end surfaces 47 and 48. Referring to FIGS. 4, 5 and 6 in conjunction with FIG. 3, and particularly to FIG. 5, it will be seen that the "lowest" position occupied by follower 42 is when follower 44 engages end surface 47 of cam 40, the follower in this position fitting into the deep recess at the left-hand end of the cam (as viewed in FIG. 3). By the term "lowest" is meant the position wherein follower 44 most nearly lies parallel to arm 39. In this lowest position, rotation of arm 39 by strike 23 in the direction of arrow 36 will cause follower 42 to engage the cup-shaped end portion of stop 45, which is positioned at the same height above or outward from first member 18 as is follower end 44. The next highest stable position that may be assumed by follower 42 is adjacent end section 48 of first cam 40, the follower in that position having ridden out of the recess in the cam 40 and onto the raised section adjacent stop 48. The highest position which follower 40 may assume, as will be illustrated in later figures, is atop second cam 41. It will be seen that stop 46 and end surfaces 47 and 48 extend upwardly or outwardly to a position above the aforedescribed highest position assumed by follower 42.

Before describing the operation of the rotation control means 38, reference is made to FIG. 7 which illustrates the unlatched position of my latch. In the unlatched position, strike 23 has rotated from the latched position of FIG. 2 in the direction of arrow 36 a total of 90.degree.. Such rotation serves to align the plane of projecting portion 29 with restricted opening 27 and to alleviate the restrictive frictional latching engagement between catch spring 24 and enlarged sector 32. In this position, a resilient gasket (not shown) which may be positioned between members 18 and 20 to provide an air seal therebetween and which is normally compressed when members 18 and 20 are moved to the closed position will urge member 18 to move away from member 20 toward the open position.

Turning now to the operation of my device and beginning with the closed position illustrated in FIGS. 2-6, when members 18 and 20 are moved toward each other from the closed position, strike 23 and attached arm 39 will be rotated in the direction of arrow 36 by the engagement between catch spring 24 and cam surfaces 34 and 35. As arm 39 rotates, follower end 44 engages stop 45. Continued rotation of arm 39 causes follower 42 to move along first cam 40 to a position adjacent end surface 48 as illustrated in FIGS. 8-11. When this position has been attained, strike 23 is prevented from rotating further in the direction of arrow 36 by the engagement of end surface 48 with the follower 42 which is being held by stop 45. The position of FIGS. 8-11 is intermediate to the latched and unlatched positions; yet, as is seen in FIG. 11, enlarged sector 32 is retained within catch spring 24 and door 13 is therefore held closed.

At this point, it is important to note the operational movement of stop 45 as is best illustrated by comparing its position in FIGS. 5 and 10. Stop 45 comprises a resilient arm 53 secured at one end through a spacer 54 to first member 18. In the transition between the positions of FIGS. 5 and 10, stop 45 arches upwardly while still retaining follower end 44.

When the force tending to move member 18 toward member 20 is released, catch spring 24 disengages cam surfaces 34 and 35, and weight 51 causes arm 39 and strike 23 to rotate in the direction opposite arrow 36. During such counterrotation, follower end 44 disengages stop 45 yet remains positioned on first cam 40 adjacent end surface 48. The extent of counterrotation is limited by stop 52, and the first latch element 21 comes to rest in the position of FIG. 12. As follower end 44 no longer engages stop 45, the stop 45 and resilient arm 53 return to their normal horizontal position as illustrated in FIG. 5.

In the position of FIG. 12, the first latch element 21 is "cocked" for unlatching. Any subsequent movement of member 18 toward member 20 will result in follower end 44 passing "above" or out of range of stop 45 which will permit strike 23 to rotate completely to the unlatched position of FIG. 7. It is the function of the rotation control means 38 to operate as aforedescribed to require this "cocking" of the first latch element 21 before unlatching may be accomplished in order to provide for the problem of overclosure. For example, should overclosure occur, door 13 and first latch element 21 will be moved from the open position of FIG. 1 through the closed position of FIG. 2 to the intermediate position of FIG. 8 whereupon strike rotation will be terminated by first stop 45 as aforedescribed, and the first latch element 21 will then counterrotate to the position of FIG. 12. Here the requirement of "cocking" the first latch element 21 prohibits the complete unlatching of door 13 during overclosure.

Therefore, it will be understood that the position of FIG. 12 may be achieved either by the steps of normal closure followed by manual movement of member 18 toward member 20, or by the single step of overclosure. From the cocked position, strike 23 and arm 39 will once again rotate in the direction of arrow 36 toward the unlatched position as member 18 is moved toward member 20.

Rotation in the direction of arrow 36 is limited at this time not by first stop 45 but by second stop 46. It will be seen in FIGS. 13-15 that immediately before strike 23 reaches the unlatched position, follower end 44 is lifted off first cam 40 by an inclined portion 55 of second cam 41. Rotation is then limited by contact between follower 42, second stop 46 and end surface 48. At this point, strike 23 has assumed the unlatched position of FIG. 7, and as previously explained, door 13 may be moved to the open position. Thereafter weight 51 once again causes counterrotation of arm 39 in the direction opposite arrow 36.

During such counterrotation, end surface 47 contacts follower 42 and causes it to move along second cam 41 as shown in FIG. 16. Follower 42 then drops off second cam 41 and onto first cam 40 adjacent end surface 47. In returning to the latched position of FIGS. 3-5, follower end 44 contacts the rear curved face of stop 45 causing stop 45 to deflect downwardly permitting passage of the follower end 44. Once again the first latch element 21 assumes the position of FIGS. 3-5. Subsequent movement of door 13 to the closed position will either result in strike 23 engaging catch spring 24, as shown in FIG. 2, and the first latch element 21 assuming either the position of FIG. 3 or of FIG. 12, depending on whether or not overclosure occurs as explained above.

It will be apparent to those skilled in the art that various minor modifications of structural design and arrangement may be made to facilitate production and to reduce stresses on the components of my latch. For instance arm 39 may be recessed into door panel or first member 18 such that the function of stop 52 is performed by the recess. Likewise the alignment of restricted opening 27, projecting portion 29, and stop 46 may be adjusted such that follower 42 will not contact end surface 48 in the unlatched position, thereby reducing stress on the latch components.

As was previously mentioned, my latch is particularly adapted for use in connection with appliance cabinets and the like wherein it is desirable to provide a latch mechanism of the push-to-release type which is of simple construction and which will releasably retain the closure in a latched configuration despite any overclosure action which may occur in latching. From the foregoing description it should now be apparent that the present invention, comprising only a few moving parts adapted to interact to overcome the problem of overclosure, provides such a latch which is well suited for service on appliance and other cabinets.

As will be evident from the foregoing description, certain aspects of the invention are not limited to the particular details of the construction of the example illustrated, and it is contemplated that various other modifications or applications will occur to those skilled in the art. It is therefore intended to cover such modifications and applications as do not depart from the true spirit and scope of the invention.

Claims

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A push release latch for first and second members movable toward each other to a closed position and away from each other to an open position, comprising:

a first latch element carried by the first member;

a second latch element carried by the second member;

at least one of said latch elements adapted for rotation relative to the other latch element between a latched position and an unlatched position;

cam means associated with said latch elements for rotating said one latch element toward said unlatched position when the members are moved toward each other from the closed position;

whereby the members may be released by the latch from the closed position by moving the members toward each other from the closed position; and

a rotation control means, associated with the latch element adapted for rotation, to require rotation of said latch element to a position intermediate said latched and unlatched positions and a return rotation to said latched position before said latch element may be rotated to said unlatched position;

whereby the members may not be released by the latch from the closed position for movement to the open position until said latch element adapted for rotation has been rotated to said intermediate position, has been returned to said latched position, and has been rotated to said unlatched position by moving the members toward each other from the closed position.

2. A push release latch for first and second members movable toward each other to a closed position and away from each other to an open position, comprising:

a first latch element carried by the first member and adapted for rotation relative to the first member between a latched position and an unlatched position;

a second latch element secured to the second member;

biasing means adapted to bias said first latch element toward said latched position;

at least one of said latch elements having a cam means associated therewith for rotating said first latch element relative to said second latch element toward said unlatched position when the members are moved toward each other from the closed position;

whereby the members may be released by the latch from the closed position by moving the members toward each other from the closed position; and

a rotation control means associated with said first latch element to require rotation of said first latch element to a position intermediate said latched and unlatched positions and a return rotation to said latched position before said first latch element may be rotated to said unlatched position;

whereby the members may not be released by the latch from the closed position for movement to the open position until said first latch element has been rotated to said intermediate position, has been returned to said latched position, and has been rotated to said unlatched position by movement of the members toward each other from the closed position.

3. The invention of claim 2 wherein:

said first latch element includes a strike projecting from said first member;

said second latch element includes a catch spring adapted to engage said strike in the closed position; and

said cam means includes at least one cam surface formed on said strike.

4. The invention of claim 3 wherein:

said rotation control means includes a first stop, a second stop and a follower;

said follower and said first stop being operable to limit the rotation of said first latch element to a position intermediate said latched and unlatched positions; and

said follower and said second stop being operable to limit the rotation of said first latch element to said unlatched position.

5. The invention of claim 4 wherein said rotation control means additionally includes a first cam and a second cam, said first cam and said second cam being operable to alternatively cause said follower to cooperate with said first stop and said second stop on subsequent rotations of said first latch element toward said unlatched position.