Background of the Invention

This invention relates generally to door locks and more particularly to door locks for passage and privacy functions. Interior doors of buildings are equipped with latch assemblies often having a locking capability. A locking capability is generally desirable in doors used on bathrooms, bedrooms, and other areas where limited privacy is desired. Closets and hallways usually do not require a privacy locking capability.

During construction, handing of doors is an important consideration affecting comfort and convenience within the building. Whether a door swings inwardly or outwardly and is hinged on the right side or the left side, it will affect the necessary handing of the latch assembly to be installed. Privacy locking capability must also be appropriately oriented regardless of handing or direction of door swing. In addition, backset distance must also often be accounted for. Since standard door preparations include both

2 3/8" and 2 3/4" backset distances, this must also be considered along with the previously described locking and handing requirements .

Depending upon the size of a building, its purpose, and the styling options which are chosen, it is clear that the potential number of different latch assembly options required for different locations is

very large. This large number of options increases proportionately the potential for supply errors, inappropriate installations, delayed installations, and losses associated with replacement of erroneously installed latch assemblies.

The foregoing illustrates limitations known to exist in present devices and methods. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.

Summary of the Invention

In one aspect of the present invention this is accomplished by providing a door latch providing non-handed installation capability for passage and privacy applications, including a latch housing having a rear portion and a forward portion, the forward portion having provision for attaching a faceplate; a bolt and drawbar assembly; two independent cams mounted in the rear portion of the housing for independently operating the drawbar to retract the drawbar and bolt assembly; provision for locking either of the two independent cams; and provision for biasing the bolt and drawbar assembly to an extended position relative to the housing.

The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.

Brief Description of the Drawings

Figure 1 is a fragmentary sectional elevation view showing a preferred embodiment of the latch assembly of the present invention;

Figure 2 is a fragmentary sectional plan. view of the embodiment of Figure 1; and

Figure 3 is a fragmentary sectional elevation view showing the bolt assembly of Figure 1 in its retracted position.

Detailed Description

Referring to Figure 1, it is seen that a door latch assembly 100 according to the present invention consists of a housing with a rear portion 175, a forward portion 140, the forward portion having tabs 25

(or ears) for mounting a faceplate. Within rear portion 175 of the housing, cam 110, locking plate 115, and drawbar link 165 are seen. Note that there are two cams but only one can be seen in this view, and drawbar link 165 is found both above and below cam 110. Note also that the door latch assembly 100 shown here is symmetric about an imaginary horizontal center plane in Figure 1. "U" shaped drawbar link 165 extends within forward portion 140 to connect with bolt 60 by registering with groove 161 or 61 between bolt bosses

164 and 63 or boss 63 and bolt stop ring 62.

Figures 1 to 3, considered together, provide a clear demonstration of features of construction and function of the preferred embodiment. Rear portion 175 of the latch housing contains independent cams 109 and 110 separated by cam spacer 90. Cam lock 115 is mounted forward of cams 109 and 110 and can be moved transversely within the housing by pushing lock pin 119 or 120. If pin 119 is pushed, cam lock 115 moves such that lock tongue 118 becomes engaged with cam slot 111 of cam 110 to immobilize the cam. Independent cam 109, however, is still operable; and, when cam 109 is turned to retract bolt 60, drawbar link 165 retracts, and cam surface 166 of link 165 engages guide 117 of locking plate 115 and moves it to a centered, or unlocked, position so that both cams 109 and 110 are again free

to operate. The same action between cam surface 166 of drawbar link 165 and guide 117 of lockplate 115 results when bolt 60 is pushed back into the housing, for example, when the door is being closed. When a faceplate is in place, extension of bolt 60 is limited by bolt stop ring 62.

Forward portion 140 of the housing is composed of outer housing 150 and inner housing 125. Inner housing 125 telescopes within outer housing 150 in order to accommodate the 3/8" difference between 2 3/4 and 2 3/8" backset distances. Bolt 60 is also adapted to accommodate that difference.

Since inner housing 125 telescopes within outer housing 150, a bias spring 190 is provided to maintain a bias between the inner forward face of outer housing 150 and the rear face of inner housing 125. Spring 185 biases bolt 60 to extend from inner housing 125 so that, unless retracted by action of cams 109 or 110 and link 165, bolt 60 remains extended. The dual backset capability described is provided by slots 161 and 61 which lie between rearward bolt boss 164 and center bolt boss 63, and the rear face of bolt stop ring 162 and center bolt boss 63, respectively. Boss 164 is oriented with its long flat faces parallel to the long elevation face of bolt 60, while boss 63 is axially turned to a 45 degree offset from the bolt boss 164 and the bolt face. Since the opening in the forward portion of link 165 has its long dimension oriented transversely with respect to that of boss 164 when in the operating position, and since motion of link 165 between grooves 161 and 61 only requires a 45 degree rotation in order to pass center bolt boss 63 through the opening of link 165, it can be seen that bolt 60 is secured to link 165 under operating conditions of the assembly.

Inner housing 125 has a boss 126 which protrudes slightly through slot 151 of outer housing

150. Slot 151 is substantially "U" shaped with its legs axially spaced by 3/8", center to center, and a circumferential extent of 45 degrees. Boss 126 and slot 151 guide the rotation and telescoping movements of inner housing 125, outer housing 150, and bolt 60. This 45 degree rotational limitation prevents disconnection of bolt 60 when the faceplate is in place.

The door latch of the present invention with all of, the versatility embodied therein, provides almost universal application capability for passage and privacy applications.