Improvements in or relating to Panic Bolts.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Panic Bolts.
I, HENRY CLARKE PRUCE, of the Firm of A. Brown and Company, of Small-
brook Street, in the City of Birmingham, Merchant, do hereby declare the nature
of this invention to be as follows;-
This invention relates to panic or crush bolts applied principally to the exit
doors of theatres, concert halls and other public buildings, and has for its object,
to provide an efficient mechanism for automatically drawing the bolts on the
weight of a crush being exerted against the inside of an exit door.
According to my invention the crush or operating bar is disposed horizontally
and at a short distance from the back of the door, and is supported near its
ends by a pair of cranked arms or levers, directed downwardly and with their
inner ends pivoted upon pins or fulcra on the door. One of these arms is
arranged to work a bolt or bolts whose rods move or slide in opposite directions,
with their ends taking (when the door is locked) into sockets or staples in the
door frame.
This crush bar rocks about the pivoted ends of its supporting arms as centres,
and transmits its motion by means of one of the supporting arms taking through
and working in a long slot in the casing, to a rollered or other stud or pin car-
ried at the back edge of a sliding rack, whose fore part is continued into a long
rod or bolt, whilst the teeth on the inner or front edge engage or mesh with the
teeth of a loosely mounted pinion meshing with the teeth of, and adapted to
communicate motion to, a second rack carrying the second bolt which moves in
the contrary direction to the first-named bolt.
These bolts or their rod extensions work within guides secured to the back of
the door and the toothed wheel and rack mechanism is covered in by a cap or
casing, through and within which, the inner end of the cranked" crush-bar
support takes and works as aforesaid in transmitting movement from the said
crush bar to the mechanism.
Thus, on the weight of a crush coming against the bar, it is forced forwards and
its supporting arms are caused to rock upon the centres or fulcra at the lower
ends of them, and through the intervention of the rollered pin, one of them
causes the one rack and its bolt rod to slide inwards, whilst the intermediate
pinion communicates a corresponding movement, but in the reverse direction,
to the other rack and bolt, whereby both the bolts are simultaneously with-
drawn and the door freed.
Did 12th day of July 1899

page_text: Improvements in or relating to Panic Bolts.
I, HENRY CLARKE PRUCE, of the Firm of A. Brown and Company, of Small-
brook Street, in the City of Birmingham, Merchant, do hereby declare the nature
of this invention and in what manner the same-is-to be performed; to be parti-
cularly described and ascertained in and by the following statement:-
This invention relates to panic or crush' bolts applied principally to the exit
doors of theatres, concert halls and other public buildings, and has for its object,
to provide an'efficient mechanism for automatically drawing the bolts on the
weight of a crush being exerted against the inner side of an exit door.
Figure 1 of the accompanying drawing represents a front elevation of a panic
bolt constructed according to my invention, with the cover or front plate of the
casing removed to show the construction and arrangement of the internal
mechanism.
Figure 2 represents a vertical section of the holt, upon the dotted lines
Figure 1, the parts of the mechanism in both these said Figures 1 and 2, being
shown in their normal or fastening positions.
B
Figure represents a like sectional view as Figure 1, but with the parts of the
mechanism in the position they assume when the bolt-rods have been withdrawn
by the pressure of a crowd against the crush-bar.
Figure 4 is a perspective view of my improved panic bolt, showing the same
applied to a theatre or like door...
The same letter of reference indicate corresponding parts in the several
figures of the drawing.
According to my invention the crush or operating bar is disposed horizon-
tally and at a short distance from the back of the door band is supported near
its ends by a pair of cranked arms or levers c, d, directed upwardly and with
their inner ends pivotted to and turning upon pins or fulcra such as c¹, which
is carried by a bracket or extension of the bolt casing. One of these arms c,
is arranged to work a pair of bolts or rods e, f which move or slide in opposite
directions, with their ends e¹, f¹, taking respectively (when the door is locked)
into a top socket or staple e let into the cross bar of the door frame and a bottom
socket f, let into the floor.
This crush bar rocks about the pivotted ends of its supporting arms as centres,
and when forced towards the door by the pressure of a crush into the posi-
tion shown in Figure 3, its motion is communicated to the bolt withdrawing
mechanism, thus, the supporting arm c, which extends through and works within
a gap h, in the cover plate 2, of the casing, has a slot, which is engaged
by a rollered or other stud or pin f³, carried at the back edge of a sliding rack f*,
whose lower part is continued into the long rod or bolt f, whilst the teeth f³ on
the inner or front edge engage or mesh with the teeth of a loosely mounted
pinion, meshing also with the teeth e, of, and adapted to communicate motion
to, a second rack e, in connection with the second bolt e, which moves in the con-
trary direction to the first-named bolt.
These bolts or their rod extensions work within guides j, secured to the back
of the door whilst other guides for the same are formed in the ends of the
casing which encloses the toothed wheel and rack mechanism.
On the weight of a crush coming against the bar, it is forced forwards and
its supporting arms are caused to rock upon the centres or fulcra at the lower
ends of them, and through the intervention of the rollered pin, one of them
causes the one rack and its bolt rod to rise or slide inwards, whilst the inter-
mediate pinion communicates a corresponding movement, but in the reverse

page_text: direction, to the other rack and bolt, whereby both the bolts are simultaneously
withdrawn and the door freed.
To maintain the crush bar in its forced in position and to prevent the bolts
dropping on the pressure upon the bar being relieved, I provide the supporting
arm c, with a loosely pivotted catch k, which normally hangs down as repre-
sented in Figure 2, but when the crush bar has been raised, the nose 3, of this
catch falls into engagement with the bottom of the slot or gap h, in which
the arm works and so constitutes an automatically-operating means for retaining
the bolts in their withdrawn positions.
It is obvious that instead of one of the cranked levers supporting the crush
bar directly to one of the bolts whose motion is communicated to the other bolt
by rack and pinion mechanism, I may arrange for the fulcrum end of the said
crush bar lever to carry, or be directly or indirectly connected with, the pinion,
and for the racked ends of the bolts to come respectively on either side of the
said pinion.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is: -
:-
First In panic bolts having a pair of bolts sliding in opposite directions
and operated by a crush bar; mounting the said crush bar upon cranked arms
or levers, one of which is connected with rack-and-pinion mechanism, whereby
the bolts are simultaneously operated when the crush bar is forced inwards or
towards the door, substantially as herein described and also as set forth in the
accompanying drawings.
Secondly In panic-bolts having a pair of bolts sliding in opposite directions
and operated by a crush bar, mounting the said crush bar upon cranked arms
or levers, one of which is directly connected (at a point between its fulcrum
and the bar) to one of the bolts, whose motion is communicated to the other bolt
through the medium of rack-and-pinion mechanism, when the crush bar is forced
inwards or towards the door substantially as herein described and also as set
forth in the accompanying drawings.
Thirdly: The combination with panic-bolt mechanism operated by a crush-
bar and constructed and arranged as referred to in the preceeding claims, of a
catch, such as k, by which the bolts are automatically maintained in their with-
drawn positions, substantially as herein described and also as set forth in the
accompanying drawings.
Dated this 27th day of March 1900
HENRY CLARKE PRUCE.
By Henry Skerrett,
24, Temple Row, Birmingham, Agent for Applicant.