Spring latch mechanism

A spring latch mechanism for releasably retaining longitudinally slidable members in preselected relationships includes an elongated strip of semi-rigid resilient material having a pair of longitudinally spaced protuberances extending away from opposite faces of the strip. The strip is of flat V-shaped longitudinal cross-section and has a pivot location so that the protuberances are resiliently urged into openings in the slidable members to lock the members into preselected relationships. At least one of the protuberances can be depressed in a manner such that the other protuberance is moved out of the opening in which it was received to allow the members to slide longitudinally into another desired relationship. The strip is adapted to be disposed in a space between the longitudinally slidable members in a concealed location.

BACKGROUND OF THE INVENTION 
Numerous devices have been employed for locking longitudinally slidable 
members in preselected positions. A commonly used system is a set screw 
which is threadably received in one member and adapted to be advanced 
tightly against the second member to prevent relative sliding movement. 
Some such set screws employ a knob which can be manually turned so that a 
screwdriver or other such implement is not needed. 
Other systems employed for releasably retaining longitudinally slidable 
members in preselected positions include a button attached to one of the 
slide members and biased away therefrom so as to fit into one of a 
plurality of openings provided in the other of the members to prevent 
relative sliding movement. The button is depressible to remove it from the 
opening so that the members can be slid relative to each other into 
different positions. 
One other system for releasably locking longitudinally slidable members in 
preselected positions utilizes a multipiece unit having a button 
protruding through one of the slidable members at an easily accessible 
location and a second button protruding through one of a plurality of 
holes in the other sliding member in a nonvisible position so that upon 
depression of the first button the second button is removed from its 
locking position in one of the openings whereby the members can be slid 
until a desirable relative relationship is obtained. Upon obtaining the 
new relationship the first button can be released to allow the second 
button to protrude into another hole in the second member. This system, 
however, consists of several component parts which make it relatively 
expensive to manufacture and more susceptible to malfunction than a 
simpler system. 
SUMMARY OF THE INVENTION 
The present invention is concerned primarily with a new and improved spring 
latch mechanism for retaining longitudinally slidable members in 
preselected positions and more particularly with a spring latch mechanism 
which can be employed in retractable awnings to retain brace members in 
preselected positions. 
The spring latch mechanism or system of the present invention includes as a 
primary element thereof an elongated strip of semi-rigid resilient 
material, such as spring steel, which has been shaped and formed to 
cooperate with openings provided in adjacent slidable members to 
releasably lock the members in preselected relative positions. 
The strip is of leaf spring configuration and formed to have a pair of 
protrusions or buttons thereon each extending away from the strip in 
opposite directions at longitudinally spaced locations. A first of these 
buttons is adapted to protrude through an opening in one of the slidable 
members while the other protrusion is adapted to fit into any one of a 
plurality of openings in the other slidable member. The strip is pivotally 
secured to one of the slidable members at a location between the two 
protrusions so that depression of the first protrusion will cause the 
second protrusion to retract from its disposition in a hole in the second 
slidable member, and release of the first protrusion will allow the second 
protrusion to be forced into a selected opening in the second slidable 
member due to a bias placed thereon by the leaf spring configuration of 
the strip. 
Accordingly, it is a primary object of the present invention to provide a 
new and improved spring latch mechanism that can releasably retain 
slidably related members in preselected positions. 
It is another object of the present invention to provide an inexpensive 
spring latch mechanism utilizing a unitary part which is virtually free of 
malfunction. 
Other objects, advantages and capabilities of the present invention will 
become more apparent as the description proceeds when taken in conjunction 
with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring first to FIG. 1, a house trailer 10 is illustrated having a 
retractable awning 12 mounted along one side thereof. The retractable 
awning 12 includes an awning sheet 14 anchored along an inner edge 16 to a 
vertical side wall 18 of the house trailer with the opposite or outer edge 
20 secured to a lead bar 22 which in the preferred form, is a roll bar 
adapted to be moved between a retracted position (not shown) immediately 
adjacent to the side wall and an extended position spaced laterally from 
the side wall (FIG. 1) in which position the awning sheet is extended 
across an area immediately adjacent to the house trailer. The awning sheet 
14 is supported at opposite ends by a pair of upper brace members 24 and a 
pair of lower brace members 26, each of which includes inner and outer 
sliding arms 30 and 28 respectively so that the braces are longitudinally 
extensible and retractable to move the awning between the extended and 
retracted positions respectively. Both the upper brace members and the 
lower brace members incorporate latching mechanisms or systems 32 to 
secure the inner and outer arms in selected longitudinal positions. Both 
of the brace members utilize the latch system 32 as illustrated in FIGS. 2 
through 4 which will be described in more particularity hereinafter. 
The latch system 32 will be described in connection with the lower brace 
members 26 which, as mentioned previously each consist of inner and outer 
sliding arms 30 and 28 respectively. The outer sliding arm 28, as seen 
best in FIG. 4, is generally C-shaped in transverse cross section having 
arcuate side walls 34 and 36 and a generally flat bottom wall 38 to define 
an elongated channel therewithin. Each arcuate side wall 34 and 36 and the 
bottom wall 38 has a pair of elongated inwardly directed guide fingers 40 
extending the entire length of the outer arm. The guide fingers, in 
cooperation with inturned ends 42 on opposite sides of the opening 44 in 
the outer arm cooperate in defining a pathway along which the inner arm 30 
is confined for longitudinal sliding movement relative to the outer arm 
28. 
The inner arm 30 is also of generally C-shaped tranverse cross section 
having a pair of parallel side walls 46 and 48 and a bottom wall 50 which 
are substantially parallel to the corresponding walls of the outer arm 28. 
The side wall 48 of the inner arm is provided with a plurality of 
longitudinally spaced circular openings 52 therethrough, as best 
illustrated in FIG. 2, while the corresponding side 36 of the outer arm 28 
has one such circular opening 54 which is of slightly larger diameter than 
the openings 52 in the inner arm. The openings, 52 and 54, as will become 
more clear later, are adapted to cooperate with an elongated spring strip 
56 in facilitating relative movement of the inner and outer arms between 
selected positions. 
The spring strip 56 is of generally V-shaped longitudinal cross section 
when free standing and functions as a leaf spring. The strip 56, as seen 
best in FIG. 6, includes a relatively thin elongated portion 58 extending 
in one direction from the apex 60 and a relatively broad elongated portion 
62 extending in the opposite direction from the apex 60. Near the apex, 
the strip is deformed to form a cylindrical protrusion or button 64 
extending away from one flat side 66 of the strip while a similar but 
larger protrusion or button 68 is formed in the broad portion 62 of the 
strip near the terminal end of that portion. As will be appreciated, the 
relatively large protrusion 68 extends away from the opposite flat side 70 
of the strip for a purpose to be described later. 
At approximately midway between the large and small protrusions 68 and 64 
respectively an opening 72 is provided through the broad portion of the 
strip and a raised arcuate shoulder 74 surrounding the opening is provided 
to extend in the same direction as the large protrusion 68. The shoulder 
74 and opening 72 define a pivot location 76 for pivotally securing the 
strip to the outer arm 28 as by a rivot 78 and collar 80 shown best in 
FIG. 5. 
The collar 80 is inserted into the opening 72 in the strip and has a 
circular arcuate surface 82 adapted to mate with a mating surface 84 on 
the shoulder 74 while the rivot 78 extends through the collar and is 
secured in position in a conventional manner so that the strip 56 can 
pivot or rock about the collar. 
When the strip 56 is positioned in a space 86 between the inner and outer 
arms 30 and 28 respectively so that the large protrusion 68 extends 
through the opening 54 in the outer arm and the small protrusion 64 
extends through one of the openings 52 in the inner arm, inward movement 
of the large protrusion is resisted by the flexible but resilient thin 
portion 58 of the strip, which as can be appreciated, is bent at the apex 
60 so that the thin portion engages the side wall 36 of the outer portion 
28. The broad portion 62 of the strip is bent along opposite sides to form 
raised flanges 88 which reinforce the broad portion and thereby 
substantially prevent it from flexing. 
The strip is preferably made of a semi-rigid but resilient material such as 
spring steel so that the broad portion 62 can be rigidified with the side 
flanges 88 to form a relatively rigid section while the thin portion 58 
can flex to function like a leaf spring to bias the protrusions 64 and 68 
into the openings in the inner and outer arms respectively for desired 
operation of the latch system. As will be appreciated, the broad portion 
62 of the strip has a tail 90 beyond the large protrusion 68 which is 
adapted to abut the side wall 36 of the outer arm 28 when the large 
protrusion is in a protruding position relative to the opening 54 as 
illustrated in FIG. 5. 
As illustrated best in FIGS. 4 and 5, the spring latch system 32 in its 
operative position is disposed so that the large protrusion 68 extends 
through the opening 54 provided in the side wall 36 of the outer arm 28 
while the smaller protrusion 64 extends through one of the longitudinally 
spaced openings 52 provided in the side wall 48 of the inner arm 30. The 
protrusions of course are yieldingly urged into these openings by the 
spring bias of thin portion 58 of the strip 56. Upon depression of the 
large protrusion, which extends outwardly in a readily accessible 
location, the broad portion 62 of the strip will pivot about the pivot 
location 76 thereby withdrawing the small protrusion from its position in 
an opening 52 of the inner arm so that the inner arm can be slid 
longitudinally relative to the outer arm. Once the small protrusion is 
aligned with another desired opening 52 in the inner arm, the small 
protrusion will snap into this opening due to the bias placed thereon by 
the narrow portion 58 of the strip thereby again securely locking the 
inner and outer arms and preventing relative longitudinal movement. 
A preferred embodiment of the present invention has been described with a 
degree of specificity to enable a relatively full and complete 
understanding of that embodiment. It should be understood, however, that 
the present invention is defined by the following claims which are 
intended to encompass a scope of the invention to the extent that the 
prior art allows.