US 3596952 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
United States Patent Inventors Ewan M. l-linkle Laguna Niguel; David E. Hall, Costa Mesa, both of, Cnllll. Appl. No. 37,579 Filed May 15, 1970 Patented Aug. 3, 1971 Assignee Shur-Lok Corp., Santa Ana, Calif.
LATCH ASSEMBLY 7 Claims, 8 Drawing Figs.
11.8. C1 292/27, 292/29, 292/30, 2921124, 292/127, 292/D1G. 37 Int. 0131 E05: 9/08, 1505c 9/14 Field of Search 292/25- -27, 29-30, 92-93, 9598, 100, 121-124, 126-127,.22-1, D10. 34, DIG. 37, DIG. 42, 224, 226; 70/69, 71, 76
 References Cited UNITED STATES PATENTS 1,422,691 7/1922 Gape 292/111 1,564,593 12/1925 Lawrence 292/96 3,199,322 8/1965 Brown 70/240 FORElGN PATENTS 167,727 2/1951 Austria 292/98 Primary Examiner-Robert L. Wolfe Attorney-Lynn H. Latta AhS'llRAC'lI: A slide button actuates a bellcrank or pair of bellcranks which in turn latch or latches by converting the linear motion of the slide button to rotary motion and transmitting this motion through connecting rods to the latch or latches. The button, its housing, the bellcranks and rods are embodied in a planar assembly which can be quite thin for maximum concealment in a door panel or the like.
PATENTED A 3197' 3,596,952
36 37 36 1/ 1,0 iii" INVENTURS BY ['VA/V M Mame LATCH ASSEMBLY OBJECTS OF THE INVENTION The invention has as its object to provide a latch assembly:
I. Which transfers linear motion to rotary motion with a minimal wear factor and concurrently is inexpensive with a high reliability factor.
2. Which transfers linear motion to rotary motion by means of a bellcrank assembly in which the projection of the bellcrank rides on an inclined plane in the handle assembly.
3. Through which a reverse actuation of the latch assembly, i.e., pressure of the latch against the latch keeper, provides a positive actuation of the handle, thus indicating that definite latching has taken place.
4. Which, through its simplicity, is lightweight, easily maintained, and simple to repair.
5. In which both latches are connected in a positive mechanical manner whereby motion on either end of the assembly will create a reaction through the operating handle.
6. Which inherently is adjustable for various widths of closures utilizing the same basic components.
7. Which is designed so that it may be used as a double or single latch system.
8. Which, due to its compactness, may be installed in a very thin structure and can be completely obscure except for the actuating handle and latches.
DESCRIPTION These and other objects will become apparent in the following description and appended drawing, in which:
FIG. 1 is afragmentary plan view of a latch assembly embodying the invention;
FIG. 2 is an end view of the same;
FIG. 3 is a fragmentary front elevational view of the same;
FIG. 4 is a rear elevational view of the actuator button, housing and bellcrank assembly;
FIG. 5 is a vertical cross-sectional view taken on line 5-5 of FIG. 4;
FIG. 6 is an end view of the same;
FIG. 7 is a rear elevational view of one of the latch units; and
FIG. 8 is a vertical sectional view of the same.
Referring now to the drawing in detail, and in particular to FIGS. 1-3, I have shown therein, as an example of one form in which the invention may be embodied, a dual latch assembly comprising, in general, an actuator unit A, a pair of latch units B, B on respective sides thereof, a pair of actuator rods C, C extending from respective sides of actuator unit A to the respective latch units B and a pair of keepers D arranged to be engaged by the respective latch units B. Units A and B are relatively thin and flat in a common plane and the assembly of actuator and latch units and shaft is a relatively thin, planar assembly which can be largely concealed in a door panel, cover or the like. Keepers D are adapted to be attached to respective sides of a doorway or other frame structure in which the door or other closure member incorporating the latch-actuator assembly is framed. As best shown in FIG. I, the latches B project from the plane of the actuator assembly, and the keepers D are disposed at right angles to that plane. The entire assembly is readily adapted to closures of varying widths by selecting rods C of appropriate length. In some installations, one of the latch units B and its shaft C and keeper D may be omitted, and only a single latch and keeper utilized.
Actuator unit A (FIGS. 4-6) comprises a housing including a frame portion 10 of rectangular arch form, open at the bottom, a marginal flange ll of corresponding form, a pair of bearing bosses 12 extending outwardly from respective sides of frame portion 10, a central vertical guide boss 13, of bar form, extending downwardly from the top of frame portion l0, and a pair of cover-attachment bosses 14 extending inwardly from the lower ends of the sides of frame portion 10. Bosses l3 and M are recessed slightly below the plane of the rear face of flange 11, to receive a cover plate l5 which is attached to the bosses by means of screws I6. This provides in the housing a planar rear face which can be fitted to the surface of a door panel skin (not shown) to which the housing can be attached by screws or the like extended through fastener openings 17 in the flange III.
The unit A includes an actuator button comprising a slide body of bifurcated flat slab form having a central slot 21 separating a pair of opposed slide fingers 22 which embrace the guide boss 13 to guide the button in vertical sliding movement in the housing. The button has a stem 23 which projects downwardly through a slide opening defined between the bosses 14 (thereby assisting in the guiding function) and through the open bottom of the housing, for engagement by an operators fingers. The button is normally maintained in a retracted position by a pair of coil springs 24 positioned in sockets 25 in slide fingers 22 and compressively engaged against the top member of frame portion 10. In the retracted position (shown in FIG. 4) the fingers 22 are spaced from the top of the frame portion to allow for upward movement (yieldingly opposed by springs 24) to effect actuation of the latches.
In the outer sides of fingers 22 are diagonal cam slots 27 which are inclined at angles in the range of 4050 to the plane of sliding movement of the button, an optimum angle being 45", which provides maximum effectiveness of reversible action.
The bosses 12 are provided with bearing bores 29, aligned on a common axis in the plane of the actuator assembly. In the bores 29 are journaled the trunnions 30 of bellcranks having crank arms 31 and crankpins 32, the latter being received in respective cam slots 27. In the normal retracted position of the actuator button, the crankpins 32 are disposed near the upper ends of slots 27, adjacent the rear side of the housing. Upon upward movement of the actuator button, the pins 32 will be moved toward the front side of the housing as indicated by the arrow in FIG. 5, thus rocking the bellcranks in that direction. Upon releasing the button it will be returned to its retracted position by its spring loading, and the bellcranks will be rocked in the opposite direction.
Trunnions 30 are provided with squared sockets 35 in which are received squared shanks 36 of actuator rods C, of which the body shafts 37 may be of tubing. At their outer ends the rods C have squared tails 38 for attachment to latch units B.
Each latch unit B (FIGS. 3, 7 and 8) comprises a support including a faceplate 40, a sheath 41, and a bearing boss 42 having a bearing bore in which is journaled the hub 43 of a latch element having a latch hook 44. Faceplates 40 have openings for fasteners for attaching them to the same panel skin or surface to which actuator housing flange I1 is mounted. Latch hook 44 is integral with and projects radially from the hub 43 and upon rotation of the hub, it is rotated from a latched position to an unlatched position. When the latch hook is at rest, it is in the latching position projecting from sheath 41 as shown in FIGS. 1, 2 and 8. In this projected position the latch hook 44 is engageable with a lug 46 projecting laterally from a bracket ear 47 of a respective keeper D. The bracket ears 47 are attachable to doorframe members; 50.
Because of the substantially 45 inclination of the slots 27, the assembly will transfer linear to rotary motion and vice versa with maximum efficiency and minimum wear, thus achieving a high reliability factor at minimum cost of production.
The opposed surfaces defining slots 27 function as inclined planes or ramps for camming action with the crankpins 32.
Back pressure of the latch keeper against the latch will be transferred through the respective actuator rod and bellcrank to the actuator button so as to lock the button in the normal retracted position of FIG. 4, thus indicating positively that latching has taken place.
The assembly will now be seen to be of such simplicity as to be lightweight, easily maintained, and simple to repair.
lt will also be apparent that the two latches are connected positively through the actuator rods and the mechanism of actuator unit'A so that motion at either end of the assembly will create a reaction through the button of actuator unit A.
The assembly can be adjusted to different closure widths by selecting actuator rods C of varying lengths.
The assembly can be used as a single latch system simply by eliminating one of the actuator rods and latch units and using only one of each.
1. In a latch assembly:
an actuator comprising a housing defining a slide chamber for an actuator button movable on a slide axis;
a bellcrank journaled in a side of said housing on an axis transverse to said slide axis, said bellcrank having a crankpin projecting into said slide chamber;
an actuator button slidable in said chamber on said slide axis and having a laterally opening cam slot in which said crankpin is slidably received, said slot being inclined with reference to said slide axis so as to impart to said bellcrank arcuate swinging movement:
a latch unit comprising a support and latch hook carried thereby for arcuate swinging movement; and
an actuator rod coupled to said bellcrank and to said latch hook at its respective ends for transmitting rotary movement from said bellcrank to said latch hook in response to sliding actuation of said button.
2. A latch assembly as defined in claim 1;
said actuator housing being relatively shallow and fiat and disposed in a common plane with said actuator rod.
3. A latch assembly as defined in claim 2, wherein said bellcrank and latch hook have opposed, aligned sockets in which respective ends of said actuator rod are drivingly coupled.
4. A latch assembly as defined in claim 1, wherein said bellcrank is one of two bellcranks arranged symmetrically at opposite sides of said actuator unit and both connected to said button for rotation in a common direction;
there being two of said latch units disposed at respective sides of said actuator unit, and two of said actuator rods connecting them to respective bellcranks in a common plane.
5. A latch assembly as defined in claim 1;
said housing embodying a pair of bosses at respective sides thereof, said bosses being laterally spaced to define a slide opening;
said housing having a centrally disposed guide boss of bar form disposed along said slide axis and in opposed relation to said slide opening;
said button including a bifurcated slide body comprising a pair of slide fingers separated by a median slot slidably receiving said guide boss and a stem of reduced width in opposed aligned relation to said slot, said stem being slidably extended through said slide opening for operator engagement.
6. A latch assembly as defined in claim 5; including a pair of springs compressively engaged between the respective slide fingers and an opposed marginal frame portion ofsaid housing.
7. A latch assembly as defined in claim 1;
said housing embodying a marginal frame including a longitudinal top portion and respective side portions;
bearing bosses integral with said side portions and extending laterally outwardly therefrom on a common longitudinal axis;
said bellcrank being one of two bellcranks having respective trunnions journaled in the respective bearing bosses, both of said bellcranks being connected to said actuator button for simultaneous rotation in a common direction;
there being two of said latch units disposed at respective sides of said actuator unit and two of said actuator rods connecting them to respective bellcranks in a common plane.