Mechanism for controllably deadlocking a door to a door frame, for panic release

Apparatus deadlocking a door member to a door frame member, one of the members rigidly supporting a bolt to project freely in the direction of a first axis, for captivation by said mechanism, comprises: PA1 (a) a body attachable to the other member, PA1 (b) a rotary latching structure carried by the body to pivot about a second axis generally parallel to the first axis, the latching structure including a latch forming a recess to relatively receive the bolt as the members relatively close and so that the bolt pivots the latch about the second axis into full latching position, therby to deadlock the two members, PA1 (c) a confinement wall on the body to face and confine the bolt in the recess in full latching position, PA1 (d) the latching assembly including a latch dog, PA1 (e) and a blocking and unblocking part extending in co-operation with the body and movable from a first location in which the latch dog is blocked to prevent pivoting of the latch to release the bolt, to a second location in which the dog is unblocked, to allow latch pivoting.

BACKGROUND OF THE INVENTION 
This invention relates generally to mechanisms for deadlocking door members 
to door frame members in such manner as to accommodate sudden opening of 
the door members as by sudden pushing of associated panic bars. 
Safety exit doors are widely used, and they commonly incorporate lock 
mechanisms which lock the doors to door frames, and which are releasable 
by operation of panic bars. See U.S. Pat. Nos. 1,638,748; 4,130,306; 
4,083,590; and 4,368,905. 
There is need for simple, compact, reliable mechanisms of this type which 
are readily installable upon such doors and door frame members to thereby 
provide safety exit door operation. U.S. patent application Ser. No. 
067,132, filed June 29, 1987, and entitled "Lock Mechanism for a Safety 
Exit Door" provides a mechanism of this type, wherein a latching part in 
the form of a drum is rotatable about a horizontal axis to captivate a 
bolt member that projects downwardly from a door frame member. One 
disadvantage of such a latching part in the form of a drum is the 
requirement for precise relative vertical spacing of the drum relative to 
the bolt, i.e. the lack of sufficient vertical spacing tolerance as 
between the drum and bolt. Such tolerance is very desirable to accommodate 
installation of the apparatus to doors of different types and which may 
tend to move vertically somewhat as they swing between open and closed 
positions. 
Another latching mechanism of this class is shown in U.K. Patent No. 20 
80391 entitled, "Exit Door Locking Mechanisms Having Multiple Bolts." One 
problem with that mechanism is the lack of full captivation of the bolt, 
i.e. on all sides, by the latching part. 
SUMMARY OF THE INVENTION 
It is a major object of the present invention to provide an improved 
mechanism for deadlocking a door member to a door frame member, one of the 
members rigidly supporting a bolt to project freely in the direction of a 
first axis, for captivation. As will be seen, the mechanism basically 
comprises: 
(a) a body attachable to the other member, 
(b) a rotary latching means carried by the body to pivot about a second 
axis generally parallel to the first axis, the latching means including a 
latch forming a recess to relatively receive the bolt as the members 
relatively close and so that the bolt pivots the latch about the second 
axis into full latching position, thereby to deadlock the two members, 
(c) a confinement wall on the body to face and confine the bolt in said 
recess in the full latching position, 
(d) the latching assembly including a latch dog, 
(e) and a blocking and unblocking part extending in co-operation with the 
body and movable from a first location in which the latch dog is blocked 
to prevent pivoting of the latch to release the bolt, to a second location 
in which the dog is unblocked, to allow said latch pivoting. 
As will be seen, the latching means is typically rotatable in one direction 
about said second axis toward its full latching position, and in the 
opposite rotary direction about said second axis toward and into bolt 
releasing position, and including a spring associated with said body and 
rotary latching means for urging the rotary latching means toward bolt 
releasing position; also, the body typically includes a side wall 
attachable to one of said members, a top wall relative to which said 
confinement wall projects upwardly proximate one end of the top wall, 
there being an upright shaft mounted on the top wall and mounting said 
latching means above said top wall to rotate at a level proximate the top 
of said confinement wall. 
In addition, the blocking and unblocking part may comprise an elongated rod 
adapted to be carried by said other member for endwise movement relative 
thereto; the body in typically attachable to upper extent of the door 
member so that the rod extends vertically beneath the body and is adapted 
to be displaced endwise vertically by a panic bar mounted on the door 
member. The panic bar is elongated and typically has a smooth decorative 
surface which is channel shaped in cross sections. 
Also, the mechanism advantageously incorporates interengageable stops on 
the body and on said rotary latching means to limit rotation of the latch 
in one rotary direction about said second axis at said full latching 
position, and in the opposite rotary direction about said second axis at a 
bolt releasing position. 
As will appear, the bolt typically extends downwardly from a door frame 
member for captivation in the latch recess as the door closes and the 
latch rotates sidewardly about its vertical axis of pivoting, the latch 
spaced well above the top of its support plate on the body so that ample 
tolerance space is provided for bolts of different lengths or projected 
extents, relative to the mechanism. 
These and other objects and advantages of the invention, as well as the 
details of an illustrative embodiment, will be more fully understood from 
the following specification and drawings, in which:

DETAILED DESCRIPTION 
In FIG. 1, a locking bolt 10 is carried by, and projects rigidly and freely 
downwardly from a door frame upper transverse member 11, i.e. at the 
general level of the top 12a of a door member 12. Mechanisms 13, in block 
form, and incorporating the invention, is attached to the exterior 
uppermost side 12b of the door member. A panic bar 17 extends horizontally 
and is carried by the door at a lower "manual push" level; and block 14 
also carried by the door represents actuator mechanism between the bar 17 
and a vertically movable part 15, such as a rod acting as a latch blocking 
and unblocking part, as will appear. Arrows 16 indicate such rod up and 
down movement, as controlled by the panic bar. See for example the 
structures in U.K. Patent No. 20 80391. 
Referring now to FIGS. 2-6, the mechanism 13 includes a hollow metallic, 
box-like body 19 having a side wall 20 attachable to the side of the door 
12, as via fasteners 21 receivable through holes 22' in side wall 20. The 
body also includes upright flanged walls 21 and 22 integral with wall 20 
and bent at 90.degree. thereto. Walls 21 and 22 serve to support wall 23 
if and when 23 bends downward under load. Further, the body includes top 
and bottom flanged walls 23 and 24 integral with wall 20, and bent at 
90.degree. thereto. See for example bends 23a and 24a A further upright 
wall 25 is integral with top wall 23, and bent upwardly at 25a, for 
purposes as will appear. 
A rotary latching means 26 is carried by the body, and typically by top 
wall 23, to pivot about an axis 28 which extends parallel to the axis 27 
of bolt 10, both axes typically extending vertically. The latching means 
includes a latch 29 in the form of a plate which is generally C-shaped in 
horizontal plane, and forms a reces 30 having a C-shaped inner wall 30a 
defined by arms 31 and 32 of the C-shaped latch. The recess 30 is adapted 
to relatively receive the bolt 10 as the door member closes or pivots 
relatively toward the plane of the door frame member 11, whereby the bolt 
engages the inner edge 30a' of the arm 31 and forcibly pivots the latch 
plate about the second axis 28 as referred to, and into FIG. 5 position. 
In that position the bolt is confined by the C-shaped latch 29, and also 
by the upwardly projecting wall 25, referred to above. Thus, the bolt 
relatively moves from FIG. 4 position to FIG. 5 position, generally 
parallel to wall 25. In actuality, the wall 25 moves relative to the bolt, 
which is typically carried by the fixed position frame member 11. 
Pivoting of the latch is accommodated by a pivot shaft 33 carried by the 
top plate 23 to project upwardly, for spacing the latch 29 well above the 
top plate 23. Spacers 34-38 are mounted on shaft 33 and confined in 
stacked relation between 23 and 29, as shown. Other spacers may be 
employed, such as using one mechanism or spacer only. A pre-determined 
torsion spring 40 is located beneath plate 23 and wrapped about shaft 33 
to urge the shaft, latch plate and spacers in one direction in FIGS. 4 and 
5, and toward FIG. 5 position; thus as the bolt centers the recess 30, it 
rotates the latch in the opposite direction and against the force of the 
spring, further tensioning the latter. A head 41 on the lower end of the 
shaft holds the spring between 41 and 23. Torsion spring arm 42 engages 
the wall 23, and the opposite arm 43 of the spring is attached to head 41. 
Of particular advantage is the fact that the space 45 between the latch 
plate 29 and the top wall 23 accommodate bolts of different lengths, i.e. 
that project downwardly to different extents into that space, as the bolt 
moves relatively into the recess 30 during door closing. Thus, the 
invention affords wide tolerance levels for interengaging parts, upon 
latching and unlatching. 
A blocking and unblocking part, as in the form of rod 15 previously 
referred to, extends in cooperating relation with the body 19. As shown, 
the polygonal cross-section rod 15 extends upwardly into the hollow 
interior of the body, i.e. between walls 21 and 22, as via polygonal 
(square) cross-section guide openings 47 and 48 through the walls 23 and 
24. The rod uppermost extent 15a in FIG. 5 extends into laterally blocking 
relation with a latch dog 50 integral with and projecting radially 
outwardly of spacer 35, which is rotatably attached to shaft 33 as via 
engagement therewith at flat area 51. When the rod extent 15a retracts 
downwardly below the level of the latch dog, as by panic pushing of the 
bar 17, the spring urges the latch toward FIG. 4 position, suddenly 
freeing the latch from the bolt, and allowing rapid opening of the door. 
Also, the force pushing bar 17 accelerates freeing of the latch from the 
bolt. Alternatively when the rod upper extent 15a engages the dog 50 at 
50a in FIG. 5, the door is positively latched to the bolt 10. 
The plate 34 defines two angularly spaced stops or stop shoulders 75 and 76 
(see FIG. 5), alternately engageable with a stop pin 77 integral with top 
wall 23, thereby to limit rotation of the latch at FIG. 4 and FIG. 5 
positions. 
Note in FIG. 7 that the panic bar 17 is elongated and has channel 
cross-section shape with structural flanges 55 and 56 integral with 
structural web 57. A thin, metallic U-shaped finishing sheet of metal 58 
is attached to the outer sides of elements 55-57, as shown, and has a 
smooth or polished exterior surface, of chosen decorative polished bronze 
or stainless steel trim.