An Improved Automatic Bolt for Double Doors.
Year: 1887

page_text: Date of Application, 10th Jan., 1887
Complete Left, 10th Oct., 1887
Complete Accepted, 29th Nov., 1887
PROVISIONAL SPECIFICATION.
An Improved Automatic Bolt for Double Doors.
I, ADOLPHUS BEAUVAIS, Junior, of No. 83, Newman Street, in the County of
Middlesex, Manufacturer, do hereby declare the nature of this invention to be as
follows:
My invention relates to the construction of an improved automatic bolt for double
doors, and is intended to replace the well-known thumb-bolt upon that door of a pair
which is first closed, and which bolt must be properly shot before the second door is
closed, and to therefore remove the risk of uselessly locking the lock on the second
door after the first has been closed, and the shooting of its bolt overlooked.
Behind the plate of the bolt, I fix a tube within which the bolt slides.
A spiral
slot is cut in the side of the tube into which projects a stud upon the bolt. The end
of the bolt is turned outwards through the plate so as to be readily engaged by the
closure of the second door.
The action of my invention is as follows. The door upon which it is fixed is closed,
and the second one following after it presses against the projecting bolt end above
mentioned, when the stud rides up the spiral groove, and shoots the bolt into the
staple.
A suitable withdrawing spring is fitted to the bolt.
My invention can be used at either the top or bottom of the door, or at both top
and bottom.

page_text: I, ADOLPHUS BEAUVAIS, Junior, of No. 83, Newman Street, in the County of
Middlesex, Manufacturer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
My invention relates to the construction of an improved automatic bolt for double
doors.
A bolt constructed according to my invention is adapted to replace the well known
thumb or flush bolt.
A flush bolt of the ordinary construction must be properly shot by hand, before
the second door is locked; for unless said bolt shall be first properly shot into its
staple, the subsequent locking of the lock will, necessarily, fail to secure the doors.
According to my invention, the second door-that on which the lock is fixed-
cannot be completely closed, until the bolt on the first door has been properly shot
into its staple.
In carrying my invention into effect, I provide a spiral slot, or incline, with which
the bolt engages by means of a stud or studs. The inner end of the bolt projects
through the plate, so that it can be engaged by the second door as it is pushed to.
The act of completing the closure of said second door, therefore, causes the bolt to
move spirally outwards, and engage in its staple.
In order that my invention, and the means by which the same is to be carried into
practical effect, may be thoroughly understood, I will proceed to describe it in detail,
reference being had to the accompanying figures, which are to be taken as part of this
specification, and read therewith.
Fig. 1 is an elevation, partly in.section, illustrating the application of my invention
to the top of one of a pair of doors, e.g., those of a cabinet, or book case; and
Fig. 2 is an elevation, partly in section, illustrating the application of my invention
to the bottom of the same door.
Fig. 3 is a plan shewing the second door in the act of contacting with the
bolt; and
Fig. 4 is a plan shewing the relative position of the respective parts after the bolt
has been shot, and the second door closed.
Fig. 5 is an elevation; and Fig. 6, a plan taken on the line Y-Z thereof, of a
modification of my invention.
A is the door of a pair to be closed first; and, therefore, the one upon which the
bolt is to be fixed.
B is the plate of the bolt; and may either be angular, flat, or of any suitable
shape.

page_text: C is a guiding tube; and D, the bolt, adapted to slide therein. I form a spiral slot, d,
in the side of the tube, into which projects the stud, d, fast on the bolt. It is not
essential to my invention that a perfect tube be used, providing that there be surface
enough for the production of the spiral slot.
pro-
The inner end of the bolt is bent outwards at right angles, or has a pin, d²,
jecting from it, which terminates in a small knob, d³, or equivalent projection,
preferably bevelled, against which the second door, E, can bear, as it is being
closed.
Instead of making the connection between the inner end of the bolt, D, and the
projection, dd, a rigid one, I may fix the projection to a sleeve on the bolt, with
which it engages by means of a stud projecting therefrom into a vertical slot cut in
said sleeve.
A guide may be provided in which the inner end of the bolt D may work to-and-
fro. The spiral slot, d, may be replaced by a spiral groove.
F is a returning spring, on the shank of the bolt, for the purpose of withdrawing
the bolt from its staple, when the knob, d³, is freed from the pressure of the second
door E.
The action of my invention is as follows.
The door, A, upon which the bolt is fixed is closed first; and, next, the second
one, E. As the latter is pushed home, it engages with the knob, ; and pushes it
forward, thereby tending to rotate the bolt around its vertical axis. The bolt, instead
of rotating only, is moved spirally outwards by the stud, d', ascending or descending
(according as to whether the bolt is at the top or bottom of the door) the slot, d.
The position of the bolt after it has been shot in the manner described is illustrated
by the dotted lines in Figs. 1 and 2.
The modification of my invention illustrated in Fig. 5 consists in transmitting the
motion of the projection, against which the second door bears in the act of closing,
through a sleeve and stud. The projection is fast to the sleeve and the stud fast to
the bolt. Consequently, the projection moves only through an arc, the centre of
which is in the axis of the bolt, and the friction between it and the second door will
be correspondingly less.
The figure represents the inside face of a bolt for the top of a door.
B is the plate; D the bolt; d, a spiral slot, and d', the stud on the bolt.
F is the returning spring, acting between the end of the plate B and a suitable
expansion d' of the bolt D.'
G is a projection from, or extension of, the bolt at an angle therewith. It projects
outwards through the plate B, being thereby adapted to be engaged by the closing
door, E, as the latter is shut to. This projection is fast upon a sleeve, g, resting upon
the bracket, g', (utilised also as a guide for the bolt), and embracing the bolt, which,
however, is free to move therein, up or down or around its axis.
Upon the top of the sleeve, I form a spiral incline, g² (or decline according as
to whether the bolt is intended for the top or bottom of the door) which engages
with the stud, g³, on the bolt. D.
The operation of this modification of my invention is as follows.
As the second door pushes the projection, G, before it, the sleeve, g, is rotated, and
in virtue of its engagement with the stud, g³; and of that of the stud, d², in the
slot, d; the bolt D is pushed out, with a spiral motion, into its staple.
The spiral surface, 92, on the sleeve, g, of Fig. 5 may be replaced by a spiral or
a vertical slot, or groove, in it, in which the stud, g³, can engage. If a spiral slot or
groove be used, the spiral slot, d, and stud, d¹, may be dispensed with.
I wish to point out that the modification of my invention illustrated in Fig. 5, and
described therewith, is well adapted for use in long bolts for large doors by virtue of
the diminished friction and the extra provision for the bolt travelling truly
and freely.
The figures illustrate the application of my invention to a flush bolt, but I wish it
to be understood that its application is not confined to this class of bolts, but is
applicable to all bolts for double or folding doors.

page_text: Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, 1 declare that what I claim is :-
1. The combination in a bolt adapted to he fixed on one of a pair of folding doors,
of a stud on said bolt; a spiral surface with which said stud is adapted to engage ;
and a projection from the bolt, through the plate thereof, adapted to be engaged by
the closing of the second door, and to consequently impart to the bolt a spiral motion
outwards into its staple.
2. The combination of bolt; spiral surface; stud engaging therewith; projection
from the bolt adapted to be engaged by the second door; and a returning spring:
substantially as described.
3. The combination with a bolt adapted to be fixed on one of a pair of folding
doors, of a stud projecting therefrom; a spiral slot or groove in which the said stud
engages a projection upon the bolt adapted to be engaged by the closure of the
second door, and to thereby impart to the bolt a spiral motion outwards into its
staple substantially as described with reference to the accompanying drawings.
Dated this 10th day of October 1887.
PHILLIPS & LEIGH,
Patent Agents,
22, Southampton Buildings, Chancery Lane, W.C.
Agents for the Applicant.