General purpose latch

Aug. 16, 1966 w. τ. appleberry 3,266,830

GENERAL PURPOSE LATCH Original Filed April 16, 1963

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3,266,83®

Patented August 16, 1966

United States Patent Office

3,266,830

GENERAL PURPOSE LATCH

Walter T. Appleberry, Long Beach, Calif., assignor to Douglas Aircraft Company, Inc., Santa Monica, Calif.

Original application Apr. 16, 1963, Ser. No. 273,474, now Patent No. 3,208,781, dated Sept. 28, 1965. Divided and this application July 6, 1965, Ser. No.· 469,375

Claims. (CI. 292—128)

This application is a division of application Serial No. 273,474, filed April 16, 1963, entitled “General Purpose Latch,” nov>' Patent No. 3,208,781.

This invention relates to latch assemblies and more particularly to those types of latch assemblies which employ pivotal levers. Latches of this type are used in connection with drawers, cabinet doors and any type of closure where an aperture is provided for entry into the closure compartment. Normal closures usually have an aperture which is closed by a cover portion or the like which is hingedly mounted to one side of the closure and adapted to be latched on the opposite side of the cover portion to the closure. Such latches generally utilize a lever pivoting about a pin which serves as the axis of rotation of the lever, as well as means for holding the lever in place.

Several separate manufacturing steps are required to produce latches having pivot pins. Also, considerable effort and special tools are required for installation of the latch to the closure. A more economical type of latch to manufacture employs a lever which is not pinned at its axis of rotation, but is fulcrumed without the use of pins and is held by guides against any sliding movement. The elimination of pivot pins furthers the economy of manufacture of the lever, but necessitates the use of other means for securing the latch in place. Prior to this invention, specially shaped springs and brackets have been employed which are fastened to the closure front or other structure to which the latch is mounted. But, the difficulty and expense of installation of such specially shaped springs and brackets is often greater than that required in the installation of latches with pinned types of levers. Furthermore, the fulcruming of the latches without pins usually causes substantial friction and wear, and the latches often do not operate smoothly.

The instant invention relates to a closure type of latch which incorporates a lever which is fulcrumed about the closure without the use of a pin. The latch assembly is supported wholly in the one portion of the closure by means of a channel-shaped pan portion. A spring member is inserted between the channel-portion and the lever to give the latch the necessary resilient latching movement when the latch is being engaged and disengaged. A hook extends from the lever to engage a corresponding strike means connected to another portion of the closure to engage the latch and close the closure compartment.

One feature of this invention is to incorporate in a latch a pinless lever which is economically manufactured and which may be quickly installed without the use of special tools.

Another feature of this invention is to decrease friction and accompanying wear which is often associated with pinless latch levers. This is accomplished by having the lever bear lightly against the guides which prevent sliding, and locating the handle portion of the lever so that the force applied to it in releasing the latch is held to a minimum.

Another feature of this invention is to form the latch levers economically as by the process of stamping or by slicing sections from an extrusion. In ordinary latches, springs are held to levers by pins, riveted or otherwise applied to the levers. This results in levers of uneven cross-sections and which cannot be easily manufactured as by extrusion or stamping. In this invention, the latch lever is formed of constant cross-section.

The incorporation of the several defined features of this invention enables the economical manufacturing of latches which may be installed in a closure in a few seconds and without the need for tools of any type. Furthermore, once installed, a lever cannot be accidentally removed and it operates smoothly and with little wear.

Accordingly, one object of this invention is to provide an easy installable latch.

Another object of this invention is to provide a latch installable in the closure without the use of tools.

Another object of this invention is to provide a latch which is held in place merely by the action of a spring.

Another object of this invention is to provide a latch using a spring bias pinless lever which operates smoothly and with little friction or wear.

Another object of this invention is to provide a latch using a spring bias pinless lever of constant cross-section which can securely retain a single spring.

Other objects and a more complete understanding of the invention will be had from the disclosures and the following detailed specification, and in claims, and accompanying drawings, wherein:

FIGURE 1 is an exploded pictorial view of the invention adapted for use with a semi-flush lever;

FIG. 2 is a partially sectional side elevational view of the latch of FIGURE 1; and

FIG. 3 is a side elevational view of the latch of FIG. 1 shown during assembly.

With reference to the accompanying drawings, FIG. 1 illustrates a latch that is substantially flush with the surface in which it is installed. This latch includes a lever 52 which extends through a pan housing 54. A coil .spring 56 is located between the pan housing 54 and lever 52. The pan 54 is channel-shaped and has a bottom portion 57, open end portions 58 and 60, and flange portions 62 extending outwardly from the open side of the channel opposite the bottom portion 57. The lever 52 includes a handle portion 64, a hook portion 66 extending substantially perpendicular to the handle portion 64, and a center portion 68 therebetween. The spring 56 is positioned on the bottom portion 57 of the pan and located in hollow portion 70 of the handle portion 64 of the lever. The latch is useful for holding, in . a closed position, a cover portion 76 or the like to which the latch is fixed, such holding being accomplished by the engagement of the hook portion 66 with a strike portion 72 which is fixedly and non-movably mounted in the closure compartment.

This invention is adapted to be installed within a generally rectangular opening 74 formed in the cover portion 76. The pan 54 is situated within the rectangular hole 74 and the flanges 62 rest upon the surface of the cover 76.

Most of the handle portion 64 of the lever lies within the pan 54. Extending portion 78 of the lever projects through the end portion 58 of the pan and the lever center portion 68 extends through the end 60¹ of the pan. .The hook portion 66 extends downwardly and engages strike portion 72.

The spring 56 located between the lever 52 and pan 54 serves to bias the handle portion 64 of the lever away from the pan. The lever 52 is held on one side of the cover 76 by the extending portion 78 and shoulder 80 which rests on the inner side 82 of the cover 76. The lever is held against lateral movement by a stepped handle boss 84 and a protrusion 86 which abuts the edges of the rectangular opening 74. A finger portion 88 formed by the boss 84 and protrusion 86 serves to indicate that the handle portion 64 should be pushed to operate the latch.

The latch is installed in the opening 74 in the manner shown in FIG. 3. The pan 54 is partially inserted

3,266,830 through the opening 74 from above the cover 76, and placed so that a cutaway portion 90' of the pan 54 rests on one edge of the cover 76. The handle portion 64 of the lever is inserted from the inner side of the cover 76 and through the end portion 60 of the pan to a position wherein the extending portion 78 projects through the end 58 of the pan and lies against the inner side 82 of the cover 76. The pan 54 is then completely inserted into the opening 74. Thereafter, the coil spring 56 is compressed and inserted through the end portion 58 of the pan 54 and located in the hollow portion 70 of the lever 52. From the foregoing description, it may thus be seen that the latching assembly is supported in relation to the cover 76 solely by the cooperation of the pan flanges 62 with the extending portion 78 and shoulder 80 of the lever 52, thereby negating any need for screws, rivets, welds, glue or other such common fastening means.

In order to remove the lever 52 from the latch, the end portion of the pan 54 must be lifted so the cutaway portion 90 rests on top of the cover 76 in a maimer similar to the method of installation of the latch shown in FIG. 3. However, when the cutaway portion 90 rests on the cover 76 the handle portion 64 of the lever 52 almost contacts the bottom portion 57 of the pan 54. The depth of the hollowed portion 70 is controlled so that the coil spring will reach full compression before the handle portion 64 contacts the bottom portion 57 of the pan 54. When the latch is assembled, the pan 54 cannot be lifted sufficiently for disassembly of the latch. The latch can be disassambled by compressing the coil spring 56 and withdrawing the end portion 58 of the pan 54.

Although the spring is designed so¹ that when fully compressed it prevents accidental removal of the latch, this feature is not necessary. The pan 54 is never lifted when the latch is in operation so there is no possibility that the latch could be disassembled accidentally. However, the design of the spring 56 does prevent undesired disassembly by those who might tamper with the latch.

To release the latch of this invention, the handle boss 84 is depressed as shown in FIG. 2. When sufficient force is applied to overcome the force of the spring 56, the handle portion 64 moves toward the bottom portion 57 of the pan 54 and the lever pivots in a direction herein defined as counterclockwise. The lever 52 may rock on the rounded shoulder 80 or on the inner radius 92 of the center lever portion 68, depending on the point of force application. Line 55 in FIG. 2 represents a center line of the spring 56. If the unlatching force is applied to the right 61 of the center line 55, such unlatching force must be greater than the force exerted by the spring 56 to provide a net counter-clockwise torque. Therefore, the net force of lever 52 will compress the spring and the lever 52 will pivot about the inner radius 92 of the center lever portion 68. Conversely, the application of the unlatching force to the left side 59 of the spring center line 55 will result in the net force on the lever being such as to cause the lever to pivot on the rounded shoulder 80.

When the lever 52 pivots counter-clockwise, the hook portion 66 disengages from the strike 72. To facilitate easy opening of the cover 76, an indentation 91 is provided in the finger portion 88. Typically, the latch is released and cover opened by means of pressure applied by a thumb of a person to the handle boss 84 and by means of the application of a pulling force applied by a finger to the indentation 91, both of these forces being applied simultaneously.

Spring 56 is so located that the force exerted on the handle boss in opening the lever is approximately equal to the force exerted by the spring. This provides for a minimum net force on the shoulder 80 so that the friction and wear on the lever 52 are at a minimum. In order to promote economy of manufacture, the lever 52 is formed of one piece of constant cross-section.

It can be appreciated from this invention that such a latch using a pinless lever operates with a minimum frictional resistance. Also, by providing a lever of constant cross-section, the latch can be economically manufactured. Other innovations shown in the particularly described embodiment such as the utilization of a coil spring to prevent accidental disassembly of the latch, insure that the latch may be easily installed, will operate smoothly and with a minimum of service problem, and will present the utmost in efficient design and operation. It should be noted that although a coil spring is shown in the embodiment, various other types of resilient means may be employed.