U.S. patent number 3,617,080 [Application Number 04/747,293] was granted by the patent office on 1971-11-02 for door latch.
Invention is credited to Wesley E. Miller.
United States Patent |
3,617,080 |
Miller |
November 2, 1971 |
DOOR LATCH
Abstract
This invention relates to improvements in door locking and
latching apparatus suitable for use with double or swinging doors
and with sliding doors. The embodiment illustrated and described in
the specification includes a plate which overlies the free edge of
one door. The vertical central section of that plate is recessed
for the full height of the door and latching apparatus including an
upper and lower bolt, means to bias those bolts upward and
downwardly respectively, and means for retracting the bolts are all
disposed within the recess. The upper bolt is adapted to cooperate
with a catch in the door frame above the door and the lower bolt is
adapted to cooperate with a catch opening in the threshold.
Inventors: |
Miller; Wesley E. (Westminster,
CA) |
Family
ID: |
25004477 |
Appl.
No.: |
04/747,293 |
Filed: |
July 24, 1968 |
Current U.S.
Class: |
292/38;
292/171 |
Current CPC
Class: |
E05C
9/045 (20130101); E06B 3/365 (20130101); Y10T
292/0841 (20150401); Y10T 292/0992 (20150401) |
Current International
Class: |
E06B
3/36 (20060101); E06B 3/32 (20060101); E05C
9/00 (20060101); E05C 9/04 (20060101); E05c
001/12 (); E05c 009/04 () |
Field of
Search: |
;292/8,32-42,141,143,145,171,175,237,DIG.16,DIG.21
;49/366-370,394-395,449 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Wolfe; Robert L.
Claims
I claim:
1. A locking mechanism for use with a door comprising, in
combination:
a structure having dimensions to form at least part of the free end
of said door, said structure being provided with an elongate recess
extending the height of the door;
an upper bolt and a lower bolt disposed in said recess and
reciprocably movable relative to said structure between a first
position in which their ends project above and below the top and
the bottom of said door structure respectively, and a second
position in which said bolt ends are retracted;
means normally biasing both of said bolts to first position;
retracting means disposed entirely within said recess in a
midregion along its length and being manually operable to retract
said bolts against said bias to second position;
in which said structure comprises a plate of dimensions to cover
the free edge of said one door from top to bottom and having guide
means formed along a central vertical section of its length on one
side thereof for confining said bolts and said retracting members
to movement in a vertical direction, said guide means comprising
structures of size to fit within an elongate recess formed in the
free edge of the material of the door and extending throughout its
height and including a track, said retraction members being mounted
upon the track and confined by the track to movement within said
guide means.
2. A locking mechanism for use with a door comprising, in
combination:
a structure having dimensions to form at least part of the free end
of said door, said structure being provided with an elongate recess
extending the height of the door;
an upper bolt and a lower bolt disposed in said recess and
reciprocably movable relative to said structure between a first
position in which their ends project above and below the top and
the bottom of said door structure respectively, and a second
position in which said bolt ends are retracted;
means normally biasing both of said bolts to first position;
retracting means disposed entirely within said recess in a
midregion along its length and being manually operable to retract
said bolts against said bias to second position;
in which said bolts are generally cylindrical including cam means
for camming said bolts to said second position upon closure of said
one door comprising a follower surface formed at the end of each
bolt in the form of a rounded end; and
in which said structure comprises a plate of dimensions to cover
the height and width of the free edge of said one door and having
its central vertical section recessed to form a channel of uniform
depth and width throughout its length; cover means for covering
said channel along all but a midregion along its length comprising
an upper cover section of dimensions to cover the upper section of
the channel above said midregion and a lower cover section of
dimensions to cover a lower section below said midregion; a pair of
guides disposed within the upper section of said channel and a pair
of guides disposed within the lower section of said channel, at
least one guide of each pair being fixed against movement, said
upper bolt being reciprocably mounted for vertical movement in said
one guide of the upper pair of guides and said lower bolt being
reciprocably mounted for vertical movement in said one guide of
said lower pair of guides; a pair of retraction members disposed
within said channel at said midregion and movable therealong, one
being movable upwardly into engagement with the lower end of said
upper cover section and the other being movable downwardly into
engagement with the upper end of said lower cover section; the
upper retraction member having connection to the upper bolt and the
lower retraction member having connection to the lower bolt; means
for biasing said upper bolt and said retraction member upwardly to
urge said upper retraction member into engagement with the lower
end of said upper section of the cover and means for urging the
lower bolt and lower retraction member downwardly and tending to
engage said lower retraction member with the upper end of said
lower cover section.
3. The invention defined in claim 2, in which said bolts are formed
with a shoulder at a point along their length and said bias means
comprises a pair of coiled springs each wound about a respectively
associated one of said bolts and trapped between the shoulder of
its bolt and one of said guides.
4. The invention defined in claim 3, in which said recessed portion
of said plate comprises a track defined by conformations on its
opposing surfaces and in which said retraction means are disposed
within said track and have complementary conformations on their
surfaces by which they are confined to vertical movement entirely
within said recess.
5. A locking mechanism for use with a door comprising in
combination:
an elongated channel member having height to extend the height of a
door and having its channel extending over that height;
means comprising a removable cover plate for covering at least all
but a central region of a channel recess;
an upper bolt and a lower bolt disposed in said recess and
reciprocably movable relative to said channel and cover plate
between a first position in which their ends project above and
below the top and bottom of said channel member respectively, and a
second position in which said bolt ends are retracted, said bolts
being carried by and removable with said cover member;
bias means normally biasing said bolts to first position; and
retracting means disposed within said central region of said
recess;
said biasing means comprising springs carried by and removable with
said cover plate.
6. The invention defined in claim 5, in which said cover plate is
divided into two separately removable sections.
7. The invention defined to claim 6, including means for permitting
assembly and disassembly of the cover plate and channel member and
retracting means by sliding the cover plate endwise upon the
channel member while precluding perpendicular separation comprising
mating tracks and conformations.
8. The invention defined in claim 7, in which saId cover plate is
divided into two separately removable sections and in which said
retracting means comprises a pair of manually engageable retraction
elements and means connecting them to respectively associated ones
of said bolts, said bias means comprising a pair of bias springs
carried by a respectively associated one of said cover plate
sections normally biasing said retraction elements into engagement
with an end of its respectively associated cover plate section
whereby each cover plate section and its respectively associated
bolt and spring and retraction element may be assembled on said
channel member as a unit.
Description
This invention relates to improvements in door locking and latching
apparatus and it relates in particular to a novel apparatus for
locking and latching double swinging doors and sliding doors.
The swinging or double door presents a latching and a locking
problem substantially different than that presented by the ordinary
single-door construction. In the swinging or double-door
arrangement, two doors are set within a single frame. Each of the
two doors is hung on a respectively associated side of the frame by
a hinge mounting so that each can be swung to the same side of the
plane which contains the frame. Each door has a width to span half
the width across the frame opening so that the free ends of the two
doors are closely contiguous when closed, that is, when both doors
are swung into the plane of the frame. Unlike the single-door
construction in which a bolt or lockkeeper carrier by the door may
be inserted in a catch mounted on the frame, the free ends of
swinging or double doors can only be latched and locked to one
another or to the threshold or the overhead section of the
frame.
In many applications for swinging doors the need for both doors to
open occurs rather infrequently. Accordingly, it is common to
provide an arrangement which permits latching one door closed and
to mount a striker and catch on its free edge which can cooperate
with the keeper or bolt of a conventional lock mounted at the free
edge of the other door. Thus, the latch is associated with the less
frequently used of the two doors. This one door is provided with a
bolt which moves vertically and engages a catch formed in the
threshold or in the overhead section of the frame. Prior art
devices which enjoy widest acceptance, especially in those
installations where the doors are to provide security against
entrance, are arranged to bolt both to the threshold and to the
frame header. When the latching structure is to form part of the
structure which serves to lock the doors closed, then the bolts and
their actuating mechanism are advantageously made inaccessible when
the doors are closed.
One of the prior art latching and locking structures for double
doors employs apparatus which is mounted at the free edge of the
door to be latched. It incorporates two bolts both of which are
movable vertically. One is moved to a position with its ends
projecting above the door so that it may engage an overhead section
of the door frame. The other bolt is movable downwardly so that it
extends below the bottom of the door where it can engage a catch
formed in the threshold. This structure comprises a plate which
fits over the free edge of the door. A central vertical section of
the plate is offset laterally from the face of the plate to form an
elongate recess which is disposed in a recess formed in the free
edge of the door upon which the plate is mounted. The sidewalls of
the recessed portion of the plate are formed with conformations
that define a track. A bolt in the form of a U-shaped channel is
disposed in this track so that the bottom portion of its U-shape
lies flush with the surface of the plate. Two such bolts are
employed, one in the lower section and the other in the upper
section of the track. The bolts extend from the bottom and top of
the door respectively to a midregion of the plate where the
contiguous ends of the bolts are spaced apart a distance
corresponding to the height of hardware employed to move the bolts
up and down. Springs are employed in the recess of the plate which
are trapped between the recess and the bolt and urge the bolt into
frictional engagement with the track portions of the plate
hopefully to prevent motion of the bolt relative to the plate
except when the bolt is moved up and down, into and out of
engagement with its catch. Swing-out handles are provided on the
contiguous ends of the bolts. These handles are designed to lie
entirely within the recess of the plate and are withdrawn from the
recess to a horizontal or near horizontal position in which they
may be used as handles to force the bolt up or down as required.
When the bolt is repositioned, the handles, which are mounted
pivotally on the bolt, are rotated back into the recess of the
plate.
This prior art arrangement has several disadvantages. Children
playing with the handles may rotate them out of the recess of the
plate to a position where they may catch clothing of passers-by or
be struck when the other door is closed. To overcome this problem,
which is troublesome in commercial and public buildings, it is
common to use a spring biasing and detent construction which will
return the handles to position within the recess in the absence of
a force holding them out in operating position. Another
disadvantage of the prior art apparatus is that one must remember
each time the door is to be locked that both latch bolts must be
moved lest the bolt handles interfere with the lock bolt or keeper.
Another serious disadvantage arises because door widths and heights
are not standard so that a substantial amount of on-the-job
fabrication is required for installation of the prior art
apparatus.
It is an object of the present invention to provide a latching and
locking system which overcomes these disadvantages.
Thus, it is an object of the invention to provide a double-latch
bolt arrangement which does not rely upon friction to maintain
proper positioning of the bolts. Another object is to provide a
latching apparatus in which the bolt actuators do not extend beyond
the free edge of the door being latched in any operating condition
of the actuators or door.
Another object of the invention is to provide a latching system in
which the door is automatically latched upon being closed. Other
objects are to provide a latching system and apparatus which is
stronger, which is less prone to rattle and sound insecure, and
which can be made inexpensively or less expensively than prior art
systems of similar apparent quality.
These and other objects and advantages of the invention are
realized in part by the provision of a locking and latching
mechanism for use with a pair of swinging doors including a free
end structure for one door which includes an elongate recess
extending throughout the height of the door; by the provision of an
upper bolt and a lower bolt disposed in that recess and
reciprocably movable between a first position in which their ends
project above and below the top and bottom of the door respectively
and a second position in which said ends are retracted; by the
provision of means normally biasing both of said bolts to said
first position; and by the provision of retracting means disposed
entirely within said recess in a midregion along the length of the
door and being manually operable to retract said bolts against said
bias to said second position.
To facilitate comparison of the invention with the prior art and to
emphasize the structural features of the invention by which the
prior art is distinguished, an embodiment has been selected which
employs a door edge plate of the kind employed in one of the prior
art devices. It is to be understood, however, that the invention is
not limited to this construction in that various modifications may
be made in this embodiment and that other embodiments are possible.
For example, it will be apparent that the invention is suitable for
use with sliding doors. In the sense that the term is employed
herein both ends of sliding doors are free and locking mechanism
according to the invention may be mounted at either end at the edge
of one end or at the side of the door at one end. The upper and
lower bolts are engaged, when the door is latched, in the upper and
lower door track structures, respectively.
In the drawings:
FIG. 1 is an isometric view of a fragment of one door of a pair of
swinging doors showing at its free edge, a latching and locking
mechanism embodying the invention and also showing a fragment of a
threshold with which that apparatus is adapted to cooperate;
FIG. 4 is a cross-sectional view is a fragmentary vertical
sectional view of apparatus embodying the invention, taken on line
2--2 of FIG. 1;
FIG. 3 is a view, partly in cross section, of a fragment of a
door-latching apparatus whose bolts are of alternative design;
and
FIG. 4 is a cross-sectional view of the locking and latching
mechanism of FIGS. 1 and 2, taken on line 4--4 of FIG. 2.
Referring to FIG. 1 of the drawings, there are shown three
fragments, all designated by the reference numeral 10, of one door
of a set of swinging or double doors. The other door of the set is
not shown in this view. That portion of the door structure which
comprises the free edge or end of the door is provided with a
recess which extends the height of the door. Advantageously, this
recess has uniform depth and width and is formed midway between the
two sides of the door. This structure may be formed integrally with
the door, that is, the recess of groove may be formed in the
material of the door. Alternatively, it could comprise an addition
to the width of the door or it could have other forms including the
one shown in FIG. 1. Here the free edge of the door material is
recessed or slotted to receive the laterally offset, channellike
section of a plate 12 which overlies the free edge of the door with
its offset channel section disposed within the recess formed in the
door material. This plate is as high as the door is high and it is
as wide as the door is thick. Thus, the end plate 12 entirely
covers the free edge or end of the door 10. The plate 12 is divided
into vertical sections each occupying approximately a third of its
width. The two outer vertical sections or strips 14 and 16 lie in a
common plane. Between them, occupying the third section, is an
elongate, U-shaped channel 18 which opens at the common plane of
the sections or strips 14 and 16. The sides of the U of channel 18
are integrally formed with the contiguous edges of the strips or
sections 14 and 16. The channel 18 and the side sections 14 and 16
are uniform in cross section throughout their length. A
cross-sectional view is shown in FIG. 4. The sides 20 and 22 of the
channel are parallel and perpendicular to the side sections 14 and
16. The bottom of the U-shaped channel is identified by the
reference numeral 24. It is perpendicular to the sidewalls 20 and
22 and lies in a plane parallel to the plane of the side sections
14 and 16. At the juncture of side section 16 and channel wall 20,
a lip 26 is formed as an integral extension of the section 16 which
extends a very short distance into the interior of the channel. A
similar lip 28, formed as an extension of the side strip or section
14 to plate 12, extends into the channel space from the side
opposite the lip 26. These two lips, or a variety of other
conformations the shape of which would occur to one skilled in the
art, form tracks for a bolt-retracting means to be described
below.
The end plate 12 shown in FIG. 1 is designed for use with exterior
doors. It is generally T-shaped in cross section. The plate member
described above, including sections 14 and 16 and 18 comprise the
stem of the T. The crossbar section is generally designated by the
reference numeral 26. One-half of this crossbar section, the half
designated by the numeral 28, overlies the exterior side of the
door 10. The other side of the crossmember, the side designated 30,
overlies the other door when it is closed upon door 10 and it
includes a weather-stripping sealing member 32 which presses
against the other door when the two are closed to seal against the
entry of moisture between the two doors. This plate configuration
has the advantage that it may be made of extruded material such for
example as extruded aluminum.
In addition to one of the structures described above which makes an
elongate recess available at the free edge of the door, a pair of
bolts are provided in the invention and they are disposed for
reciprocal motion in a vertical direction within that recess. One
bolt is arranged so that its upper end can be extended above the
top of the door and can be retracted to the level of the door. The
other bolt is arranged so that it can be extended below the level
of the door and can be retracted to the level of the bottom of the
door. Means are provided in the invention for biasing the upper
bolt upwardly so that its upper end extends above the level of the
door and for biasing the lower bolt so that its lower end extends
below the lower level of the door.
In the embodiment illustrated in the drawings, means are provided
for covering all but the midregion of the recess in the coverplate
12. Advantageously, as shown, this cover means comprises a separate
cover 34 for that portion of the recess which extends from the
upper limit of the midregion of the recess to the top of the door.
The other section 36 extends from the lower limit of the midregion
to the bottom of the door. Both of the cover members 34 and 36 are
U-shaped in cross section. They fit within the U-shaped channel 18
of the end plate so that the bottom of the U, designated 40, lies
in the same plane as the side sections 14 and 16 of the cover plate
12 such that its outer surface is flush with theirs. At the
juncture of the bottom 40 of the U and the sidewalls OF THE
U-shaped member 34, the surface is formed with conformations which
are complementary to the conformations, in this case the lips 26
and 28, of plate 12. Thus arranged, the conformations of the plate
serve as tracks for the vertical movement of the cover members 34
and 36 and to prevent withdrawal of the covers 34 and 36 except by
withdrawal at the ends of the channel section 18 of the plate.
In the embodiment of the invention illustrated in the drawings, the
two bolts are each mounted in the space between the channel section
18 and one of the two covers 34 and 36. The upper bolt is
designated 42; the lower is designated by numeral 44. Both are
cylindrical in form. The upper portion 46 of the upper bolt 42 has
a diameter greater than the lower portion 48. The bolt is guided in
two blocks 50 and 52 which are fixed between the side arms of the
U-shaped cover member 34, one near the upper end of the cover
member and the other a short distance below. The upper guide block
50 is bored to receive the upper end 46 of bolt 42 and the block 52
is bored to receive the smaller diameter lower end 48 of the bolt.
A shoulder 54 is formed at the transition from the lower diameter
section to the larger diameter section of the bolt. A compression
spring 56 is trapped between that shoulder 54 and the upper end of
guide block 52. The spring 56 supplies the bias that urges the bolt
42 upwardly so that its end extends above the door sufficiently far
to engage a bolt-receiving opening formed in a catch 58 which is
secured to the overhead section 60 of the door frame.
Cam means for camming the bolt to a retracted position is provided
in the invention. It comprises a follower surface formed at the end
of the bolt in this embodiment. The end of the bolt is rounded so
that it may follow the cam surface generally designated 62 and
formed in the striker portion of the catch 58. The lower bolt and
guide lock assembly are similar except that they are inverted. That
assembly includes the bolt 44 the end of which is rounded to form a
cam follower surface which cooperates with the surface of threshold
64 below the door. In the drawing, the threshold has been lowered
out of engagement with the bolt so that the catch opening 66 is
more clearly visible. This assembly includes guide blocks and a
springlike guide blocks 50, 52 and spring 56 of the upper assembly
but these elements of the lower assembly are not visible in the
drawings.
Means are provided in the invention for retracting the two bolts
and this means includes a pair of manually operable members which
are disposed entirely within the recess in the door in a midregion
along its height. In a preferred form the two retraction members or
elements are mounted for reciprocal movement within the recess and
are formed so that they can be squeezed together to retract the two
bolts against the bias of their respective bias springs. Means are
included for attaching these members mechanically to the bolts and
in the embodiment illustrated this means comprises a cable one end
of which is connected to the retraction member and the other end of
which is connected to the respectively associated bolt. The length
of the cable is adjusted on the job at the time of installation of
the latching apparatus to accommodate a door of any height.
Referring to FIG. 2 of the drawing, the retraction member
associated with bolt 42 is designated by the reference numeral 70.
The other retraction member 72 is associated with the lower bolt
44. These two elements include finger portions, 74 in the case of
member 70 and 76 in the case of member 72, which can be engaged by
the thumb and forefinger of one hand and squeezed together to pull
the top bolt down and the bottom bolt up. A cable 78 connects the
retraction members 70 with the lower end of bolt 42 and a cable 80
connects the lower retraction member 72 with the upper end of the
lower bolt 44.
Advantageously, the two retraction members 70 and 72 are spaced
just sufficiently, when the two bolts are extended to latching
position, to accommodate between them the keeper or bolt from the
other door, but so that the retraction members are as close
together as necessary to ensure that they can be grasped with the
fingers of one hand. To this end, means are provided in the form of
a limit stop for limiting the upward travel of the retraction
member 70 and for limiting the downward travel of the retraction
member 72. Advantageously, as shown, these limit stops comprise the
lower edge of the upper cover member 34 and upper edge of the lower
cover member 36.
If it is desired to prevent entry of the keeper into the recess of
the latched door, except when the two bolts occupy latched
position, is necessary only to replace the flexible cables 78 and
80 with links of fixed length. Thus, for example, if it is assumed
that in FIG. 2 that links or cables 78 and 80 are inflexible and if
it is assumed that the keeper 84 of the other door 86 has the width
that it is shown to have in FIG. 2 then when the bolt 42 is
retracted, or when bolt 44 is retracted, the retraction member 70
or 72 will occupy a position that interferes with proper extension
of the keeper 84.
In the modification shown in FIGS. 1, 2 and 4 the bolts slide
longitudinally within guide members the upper one of which is
designated 50. In the modification illustrated in FIG. 3, the bolt
has uniform diameter throughout its length and it is fixed to its
upper guide member 90. The guide member 90 has dimensions so that
it can slide reciprocably up and down the space between the
interior surfaces of the cover member 34 and the wall 24 of the
channel 18. The lower guide block 92 is fixed to the channel as is
the guide block 52 as shown in FIG. 2. These two guide blocks are
the same except that the opening through guide block 92 is made
larger to accommodate the larger diameter of the lower end of the
bolt 94 of FIG. 3. The bias spring 96 is trapped between the lower
surface of the guide 90 and the upper surface of the guide 92. The
modification of FIG. 3 differs from that shown in the other FIGS.
in that the member in FIG. 3 corresponding to the flexible cable 78
of FIGS. 1 and 2 has been replaced by a stiff link 98 of fixed
length.
In operation of the latching and locking system shown in the
drawings, the door 10 is closed to a position in which it lies in
the plane of the door frame while the other door remains ajar. As
the door 10 approaches the closed position, its bolts 42 and 44
will be cammed toward the second position or retracted position by
the cooperating cam surfaces of the striker and catch 58 above the
door and by the threshold and catch below the door. When the door
has reached closed position in which the upper bolt 42 is in
alignment with the catch opening 100 of catch 58, the bias spring
56 urges the bolt upwardly into the catch opening. Upward travel of
the bolt is limited by the lower stop limit surface of the cover
plate 36 when the retraction member 70 is drawn upwardly by bias
springs 56 until its upper surface engages the limit surface of the
cover. At the same time when the end of bolt 44 reaches alignment
with the catch opening 66 in the threshold the bias spring
associated with that bolt urges it downwardly into the catch
opening 66. The downward travel of the lower bolt is limited by the
upper limit stop surface of the lower cover 36 when the lower
surface of the lower retraction member 72 engages that limit
surface. As in the case of the upper bolt assembly, the lower
retraction member is pulled to position by the same bias spring
that biases bolt 44 to the latched position. The door 10 having
thus been latched, the two retraction members are spaced a distance
permitting the entry between them of the keeper 84 of the lock
mechanism of door 86. The lock may then be actuated to move the
keeper to a position corresponding to that shown in FIG. 2. The
doors having thus been closed one upon the other and locked, there
is no way to get at the retraction member to unlatch the door 10.
If the door 86 is unlocked to retract keeper 84 it may be opened to
expose the free edge of door 10. It is then necessary only to grasp
the finger portions 74 and 76 on the two retraction member and
squeeze them together to withdraw the bolts 42 and 40 from their
respective catches. The door may then be opened.
It will be apparent that the invention is useful for latching
sliding doors as well as double doors and, indeed, the door end
shown in FIG. 1 could be either end of a sliding door. In certain
sliding door installations, such for example as those which include
double sliding doors operable in parallel, side-by-side tracks, the
latching mechanism is advantageously arranged so that the recess is
formed on one side of the door adjacent one end or is formed at a
vertical corner where the side and edge meet. Alternatively, the
means for manually retracting the bolts may be accessible from the
side rather than the front of the recess.
Although I have shown and described certain specific embodiments of
my invention, I am fully aware that many modifications thereof are
possible. My invention therefore is not to be restricted except
insofar as is necessitated by the prior art and by the spirit of
the appended claims.
* * * * *