IMPROVEMENTS IN FLUSH-BOLTS
Year: 1887

page_text: Date of Application, 18th Aug., 1887
Complete Left, 16th May, 1888
Complete Accepted, 22nd June, 1888
I HENRY FREDERICK BANGERT of 72 Newman street Oxford street London W
Cabinet maker do hereby declare the nature of my invention for IMPROVEMENTS IN
FLUSH-BOLTS to be as follows:-
It is a self-acting bolt intended to secure the effectual fastening of folding-doors
whether of wardrobes book-cases French casements and the like and is of such a
nature that it operates as well in positions which owing to their height are out of
reach as it does on shorter doors. It is of the same size and has the same appearance
as flush bolts in ordinary use but excels all others in that it is shot and unshot by
the mere act of closing or opening the doors without requiring to be touched in any
way by the hand of the person using it. This automatic action I secure in manner
following. I provide at the top and at the bottom of the front edge of the left hand
door in the usual place a groove of length and depth proportioned to the bolt which
it is intended to use and which I deposit in the groove. Over the groove I place a
thin metal plate similar to those now used with the ordinary flush bolt but my plate
has a slot down the centre which admits of the free working of a pin which is
inserted in the bolt at right angles. On the front edge of the right hand door
opposite the aforesaid slotted plate, I provide another plate having a slot running
diagonally across it. The substance of the door is grooved to correspond with this
slot to a depth sufficient to admit of the free motion of the pin within it; the slot is
cut right through the edge of the plate, which is so fixed on the right hand door
that when the 2 doors are brought into contact for closing the mouth of the slot finds
itself exactly opposite the head of the pin which protrudes from the bolt in the left
hand door. At this moment the bolt is unshot, the pressure exerted on the right
hand door for the purpose of closing it forces the pin into the mouth of the slot &
the obliquity of the slot acting as an inclined plane imparts to the pin an upward
motion and the pin carries with it the bolt to which it is attached this applies to the
bolt at the top of the door but the same explanation will apply for the lower bolt it

page_text: being remembered however that the direction of the slot in the lower plate is the
reverse of the one in the upper one because the motion of the upper & of the lower
bolts is always in opposite directions at any given time. When closing the doors the
upper bolt has to be lifted and the lower one depressed whilst when the doors are to
be opened the upper bolt has to be depressed and the lower one raised, therefore at
the top of the door I provide a plate slotted from bottom to top whilst at the bottom
of the same door I provide a plate slotted from top to bottom.
My invention completely obviates the necessity for the long flush bolts now. used
as there is no need to bring the bolt within reach of the hand.
Dated this 17th day of August 1887.

page_text: I, HENRY FREDERICK BANGERT, of 72 Newman Street, Oxford Street, London, W.,
do hereby declare the nature of this invention and in what manner the saine is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The object of my Invention is to provide a selfacting bolt for effectually securing
folding doors, of book-cases, wardrobes, French casements and the like in such a
manner, that while the appearance and fitting of the improved flush bolt according to
my Invention is not externally different from those in ordinary use, the folding doors
to which it is applied may be automatically bolted by the mere action of closing the
doors, and similarly unbolted when the doors are unlocked and opened. The advan-
tage of the improved flush bolt according to my Invention over the ordinary bolt lies
in the fact that in very high doors the action of bolting is performed simultaneously
with that of closing the doors.
In order that my Invention may be the better understood I have appended the
accompanying sheet of drawings, in which Figure 1 represents a part of two folding
doors, Figure 2 front and side elevational views of the flush bolt according to my
Invention, Figure 3 the catch plate corresponding to the same, and Figures 4 and 5
represent views of a bolt and catch plate respectively, forming an alternative
device.
In carrying out my Invention I provide at the top and bottom of the front edge
of the left hand door, A Figure 1 in the usual place, a "flush" bolt, the plate e of
which is sunk so as to be flush with the edge of the door A. The bolt a enclosed by
the plate e differs in no wise from any ordinary bolt save that a projecting pin bis
attached to it, and a slot provided in the plate e to allow of the free movement of
said pin during the locking and unlocking of the bolt. The arrangement of said bolt
is better illustrated by Figure 2, where e represents the plate, 6 the pin attached to the
bolt a and d a spiral spring, which may or may not be adapted to said bolt in order
to allow of free automatic motion when required to be unlocked.
when
I wish it to be understood that the bolts should remain unlocked, or drawn, w]
the doors are open as shown by Figure 1. The right hand door B, Figure 1 is fitted
with slotted plates c at both top and bottom as shown, the position of said plates
corresponding with that of the bolts before referred to. The slotted plates c are
shown more particularly by Figure 3, and when in position upon the door, the wood
of the latter is cut away within the slot sufficiently to allow the pin b of the bolt
upon the opposite door to pass freely within said slot. It will be evident, therefore,
that when the doors A and B are closed, that the pin 6 enters into the lower part of the
slotted plate c and is forced upward by reason of the inclination of the slot, and
the bolt a is thereby shot, or locked into its socket, and cannot be withdrawn unless
the doors be opened, when it is unlocked in a similar manner.

page_text: As an alternative device I may employ a bolt of the form illustrated by Figure 4,
which is simply screwed upon the inner face of one of the folding doors, and a bent
slotted plate, shown by Figure 5 is screwed upon the opposite door, in a position cor-
responding to that of the bolt. The action of this arraugement is precisely similar
to that above described, and differs from it only in that the bolt and plate need not
be sunk into the material forming the doors, but may project beyond the inner
surface of the latter. I may or may not make use of spiral or other springs to keep
the bolt withdrawn when the doors are open, or I may depend upon the action of gravity
alone to effect the same purpose.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is,
First. In a flush bolt as applied to folding doors, the combination of a projecting
pin attached to said bolt, engaging with a corresponding inclined slot upon the edge
of the opposite door, substantially as and for the purposes herein described and set
forth.
Second. In a flush bolt as referred to in the preceding claim the use of a spring, or
of a gravity action for withdrawing said bolt when the latter is disengaged from the
slotted plate substantially as herein described and shewn.
Dated this 16th day of May 1888.
FREDK. WALKER & HYDE,
4, Little Moorfields, London, E.C.,
Agents for Applicant.
FREDK. WALKER & HYDE,
4, Little Moorfields, London, E.C.,
Agents for Applicant.