Note: Descriptions are shown in the official language in which they were submitted.
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Slam Latch
sackground of the Invention
Latches for windows, doors and the like are well
known and are generally comprised of a catch fixed to
the door or window and movably engageable with the
panel or frame of the portal in question. The catch
is engageable with a keeper that is attached to the
other panel/frame of the portal depending on the
arrangement and will so engage when the portal is in
the closed position. Metal latches on window frames
are perhaps the most familiar latches whereby the
catch pivots or swings about a post in a base secured
to one of the window frames. The catch slides under
and engages the keeper which is generally comprised of
a metal flange secured to the other frame when the
catch and keeper are in ~uxtaposition to one another.
As such, the window is closed and locked. Turning the
catch in the opposite direction unlocks the window and
allows its opening.
Latches may also be comprised of a catch that is
biased by a spring or other means that actuates the
catch in a generally lock-wise direction with respect
to the keeper. This allows for the automatic engage-
ment of catch and keeper when the window or door is
forcefully closed. There is no need for manual
manipulation of the catch into the flange of the
keeper.
The present invention is a novel latch whose
catch is biased in this manner so that when applied to
sliding doors or windows, the catch automatically
engages the keeper when the door/window is slideably
closed. The present invention also comprises a latch
that is easibly opened through the application of
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manual pressure at a point on the catch that pivotally
forces it ln a direction opposite to that of its bias
thereby disengaging it from its locked position with
the keeper so as to allow the door/frame to be
slideably opened.
United States Patent No. 3,918,754 to Isbister
shows a plastics fastener for use in an automobile
glove box whereby the latch unit is formed as a one-
piece resiliently flexible plastics material
comprising two body portions that are hinged to one
another and which are further hinged to a latch and
button respectively. Manual actuation of the button
moves the catch from an operative, keeper engaging
position to an inoperative, keeper-disengaged
position. This enables the glove box door to open
accordingly.
United States Patent 3,841,674 to Bisbing
discloses a sliding-action slam latch for securing a
door panel in closed position. The slam latch is of
one-piece construction and is installed in a single
opening in the door panel and is self retained
therein. The latch operates by a spring biased
sliding action to engage the door frame or stricker
plate. In one embodiment of the invention, the spring
bias is provided by the resilience inherent in the
plastic material from which the latch is made.
Finally, US Patent No. 5,158,329 issued October 27, 1992
also discloses a slam latch for a sliding or hinged
cabinet door that is comprised of side and rear walls
from which extends a flexible lower plate having a
catch. The latch mounts in an aperture positioned so
that the flexible lower plate extends beyond the edge of
B
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the door and over the edge of an adjacent panel to
secure the two together.
The slam action principle disclosed in the above
references is well known in the art and is embodied in a
number of designs which usually incorporate a housing
that encloses several components, one of which is a
sliding bolt or pivoting spring biased catch. The gen-
eral characteristic of these slam latches is the
actuation of the latch to secure the door or window by
cooperation with a door-frame-mounted stricker plate when
the door or window is pushed or slammed shut. In order
to open the door/window secured with such a latch, a
finger or pawl is provided for the manual exertion of
force against the spring bias which disengages the catch
from the striker plate.
The present invention is a novel slam latch for use
in sliding glass doors that is of simplistic design and
manufacture. The novel slam latch of the present inven-
tion is easy to operate and has eliminated the need for
a pinned, biased connection between the catch and
housing. Simple exertion of lateral pressure against
the resilient portion of the latch is then translated
into outward movement of the catch element itself,
thereby disengaging it from the keeper unit. The slam
latches of the present invention are particularly useful
in sliding windows of automobiles and vans.
Summary of the Invention
The present invention is a simple, easy to use slam-
latch for use on sliding doors or windows wherein a
plate serves as the attachment base for the latch to the
door/window and also serves as the pivot and retainer
for the catch, thereby eliminating the need for a pinned
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connection between the catch and housing. The construc-
tion and design of the slam latch also transfers any
force applied against the door or glass (such as
attempts at forced entry) directly from the attachment
plate to the catch, rather than from the plate through
the housing to the catch. The slam latch also includes
a spring mechanism that is integral with the catch so as
to bias it in a keeper-engaging direction and therefore
does not require a separate spring for this purpose.
Brief Description of the Drawings
Fig. 1 is a top view of the entire slam latch
assembly in operative relationship with an open
door/window.
Fig. 2 is a lateral side view of the same assembly
taken from a perspective of lines 2-2 in Fig. 1.
Fig. 3 is a lateral side view of the same assembly
set forth in Fig. 2 with the door/window in a closed and
locked position.
Fig. 4 is an exploded schematic of the catch assem-
bly showing its three operative parts - catch, base and
housing.
Fig. 5 is an exposed cross-sectional side view of
the catch assembly of the present invention in closed
and locked position.
Fig. 6 is an exposed cross-sectional side view of
the catch assembly when force is exerted to open it.
Fig. 7 is a partial cross-sectional view taken along
lines 7-7 of Fig. 5.
Detailed Description of the Invention
Referring now to Fig. 1, the entire slam latch
assembly of the present invention is shown in operative
relationship with a sliding door or window to which it
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is attached. The catch assembly (2) is secured to the
glass of the door or window using any suitable adhesive
and is aligned with the keeper element (3) which is
attached to the surrounding frame. The components may
be made out of metal or plastic although plastic is the
preferred embodiment. Movement of the door/window as
denoted by arrow A which closes same brings the catch
assembly (2) into close proximity with the keeper (3)
until they become operatively joined in a locked or
secured position as will be examined more fully below.
Referring now to Fig. 2, the catch assembly (2) of
the present invention is shown from a side view as it
appears attached to a sliding glass window or door (5).
The catch assembly (2) consists of a housing (4) which
is attached by a base plate (6) directly to the glass or
panel surface and the catch (8) itself which is one
piece construction comprised of essentially four
operative components. A spring biasing means (not
shown) operates within the housing as will be more fully
described below. A button section (10), integral and
operatively associated with said spring means, protrudes
from the housing aperture (12) and is actuated by the
application of force in the direction of arrow B.
The catch (8) extends from the button (10) by a
tongue section (16) and ends in a pointed lip (18) that
actually engages the keeper (3) and secures the
door/window in a locked position. The lip (18) hangs
down from the tongue section (16) and is separated from
the base of the housing (6) a sufficient distance (x) to
enable engagement with the keeper element.
The fixed keeper portion (3) of the slam latch of
the present invention is also shown in Fig. 2. The
keeper assembly (3) consists of the glass window or door
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panel (20) the frame (22), a U-shaped rubber gasket (24)
and the L-shaped keeper (26). As will be described in
greater detail and briefly described in Fig. 1, move-
ment of the sliding door or window for purposes of clos-
ing it (arrow A) forces the tapered lip (18) over the
U-shaped rubber gasket (24) and into a mechanically cou-
pled engagement with the keeper assembly (3) securing
and locking the window/door (5) to the frame (22) as
shown in Figure 3.
Figure 4 shows the catch assembly (2) in an exploded
perspective comprising the three unit elements, namely
the housing (4), the catch (8) and the base plate (6).
As shown by the arrows, the catch (8) fits into the
aperture of the housing (12) so that the spring means
(28) abuts with and is flush against the inside of the
rear wall (30) of the housing (4). Integral with the
spring means (28) is a pivot (32) which movably engages
a U-shaped journal (34) of the base plate (6) by a pin
or roller member (36). Assembled, the abutment of the
spring means (28) against the inside of rear wall (30)
provides a point of tension against which the spring
means (28) can bias about the pivot (32) and journal
(34).
Figure 5 show a cross-sectional lateral view of the
catch assembly (2) with the elements of Fig. 4 in assem-
bled relationship to one another. The catch (8) is con-
tained within housing (4) which is attached to the door
or window (5) by the base plate (6). The catch (8) is
secured to the housing assembly (4) by the pivot (32)
which is movably connected or inserted into the U-shaped
journal (34).
When the catch assembly (2) and keeper unit (3) are
in juxtaposition and operatively joined to one another
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such that the door or window is closed as shown in Fig.
5, the spring means (28) which comprises a flange or
lever is in abutment with the rear wall of the housing
(4). This point of contact provides the spring with a
reference to which it can bias the tongue (16) and lip
(18) downward towards the plane created by the surface
of the window or door. (arrow C). The force exerted by
the bias of the spring means (28) retains the catch (8)
in the secured or locked position when the catch assem-
bly (2) and keeper assembly (3) are in close proximityand engaging relationship with one another whereby the
door or window is closed. The same bias maintains the
catch (8) parallel with the surface of the window/door
(5) when the catch and keeper assemblies are not so
engaged. This allows for the slam-latch function of the
device as will be hereinafter described.
Figure 6 is a cross-sectional lateral view of the
present invention as shown in Fig. 5 with force (arrow
D) being applied to the button (10) so that the catch
assembly (2) is releaseably opened from the keeper
assembly (3) allowing for the opening of the window or
door in question. As can be seen from the drawing,
force applied against the button using ones thumb or
fore-finger results in a pivoting action of the catch
(8) about the U-shaped journal (34) in a clockwise
direction (arrow E) afforded by the operative connection
of the pin (36) portion of the pivot (32) to the journal
(34) in the base (6). Manual pressure against the
button (10) must be strong enough to over-come the bias
of the spring forcing the catch (8) downward (arrow C,
Fig. 5). Application of this force (arrow s, Fig. 2)
pivots the catch (8) in a clockwise direction (arrow E)
and results in the upward movement of the catch (8)
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(arrow F) thereby disengaging it from the keeper element
(26).
Assembled then, as seen in Fig. 5, the pointed lip
(18) is urged downward as indicated by arrow C by the
biased force exerted laterally by the spring means (28)
as it pushes against the inner wall of rear wall (30) as
indicated by arrow G. This is brought about by the
translation of lateral force (G) into vertical force (C)
occurring at the point where the pivot (32) and journal
(34) are rotatively coupled.
Referring now to Fig. 6, the lateral force exerted
against the button (10) (shown by arrow D) will be
resisted by the bias of the spring means (28) but, as
opposed to the bias, will translate into an opposite,
upward vertical movement of the lip (18) (arrow F)
which, operationally, disengages the catch (8) from the
keeper element (26) and allows for window/door movement.
The same upward movement (arrow F) of the catch (8) will
occur when the window/door is closed as lateral force
(arrow H, Fig. 5) is exerted against the tapered,
pointed lip (18) as the keeper element (26) is forced
against the lip (18) and moves along the slanted or
curved frontal edge (38) of lip (18). In operation,
this occurs during the sliding of the door/window to a
closed position whereby the lip (18) initially engages
the keeper which operationally engages and moves along
the lip's edge (38) until it comes to the tip (40) at
which time the compacted spring means (28) which is now
compressed forces the lip (22) down into locking engage-
ment with the keeper element (26).
Figure 7 is a cross-sectional lateral view of the
catch assembly (2) taken along lines 7-7 of Fig. 5 show-
ing the geometric and functional relationship of the
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housing t4) the base plate (6) and the pivot (32) of the
catch (8). This arrangement enables lateral forces
exerted by the bias of the spring to be translated into
longitudinal, downward forces of the catch (8) so as to
enable engagement with the keeper assembly (3) in order
to secure the door or window in the closed position.
This arrangement also enables the application of manual
force, opposite to that of the spring bias, against the
button which is then translated in longitudinal, upward
movement of the catch resulting in the disengagement of
the catch from the keeper.
Returning to Fig. 3, this operative relationship of
the catch assembly (2) and keeper assembly (3) can be
seen when the door/window is in the closed and secured
position. As the window or door is slideably closed,
the pointed tip (18) abuts the U-shaped rubber gasket
(24) which, due to its resilient character, bends and
gives way to the biased force of the spring means (28).
The L-shaped keeper (26) however, is firmly attached to
the glass/panel (20) and frame (22) and is an immovable
ledge over which the catch (8) must move. The force
exerted on the catch (8) against the keeper (26) once
contact is made moves the tapered lip and tongue in an
upward direction (Fig. 6, arrow F) as the tension
against the bias in the spring means (28) is increased.
The point of abutment between keeper (26) and lip (18)
moves along the edge of the lip (38) which may be curved
or slanted until it reaches and passes the tip (40) of
the lip (18) of the catch at which time the tension that
has built up in the spring means forces the lip (18)
downward into locking engagement with the keeper (26) as
shown in Fig. 3. The U-shaped rubber gasket (24),
extending beyond the plane as defined by the sliding
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door or window (5) is again, resilient in character,
and bends in favor thereof as engagement takes place,
thereby forming a seal at the junction between the
sliding window/door and the main frame glass or panel.
It is recognized that minor alterations and changes
can be made with respect to the slam latch as herein
described and disclosed. These changes may not be
reflected in the specific embodiments as set forth
herein but they are still considered within the spirit
and scope of the present invention as set forth in the
following claims.
