Improvements in the Manufacture of Flush Bolts for Doors and other Articles.
Year: 1889

page_text: Date of Application, 29th May, 1889
Complete Specification Left, 15th Feb., 1890-Accepted, 29th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Flush Bolts for Doors and
other Articles.
We ARTHUR GEORGE TONKS of Moseley Street Birmingham in the County of
Warwick Brassfounder and FRANCIS ROBERT BAKER of No. 167 Pershore Road
Birmingham aforesaid Mechanical Engineer do hereby declare the nature of this
Invention to be as follows:—
Our invention has reference to the cases or bodies of flush bolts and consists of
the improvements hereinafter described in making the said cases or bodies from
sheet brass or other hard and ductile sheet metal.
By our invention the manufacture of the said cases or bodies is economized they
are very strong and access of the finger and thumb to the lift or thumb piece for
operating the bolt is readily obtained.
Instead of making the case or body of the flush bolt flat and forming a box or
depression in the said flat case or body for the flush lift or thumb plate of the
bolt to work in as usual we make the greater part of the case or body of a trough or
channel form in which trough or channel the flush lift or thumb piece of the bolt
works. As the trough or channel has nearly the same width as the case or body a
broad thumb plate can be used with it and as there is no obstruction on opposite siles
of the flush thumb plate in the trough or channel the said thumb plate can readily be
gripped between the thumb and finger for manipulating the bolt..
The figure of the trough shaped body or case may be varied. We prefer
however to give it either a semi-circular form in cross section or an angular form in
cross section with flat marginal longitudinal edges.
In making the cases or bodies of the flush bolts we form by drawing or by press
tools from sheet metal a long strip having the sectional figure of the case or body to
be made. From this strip lengths are cut transversely and in each of the cut off lengths
the required fixing screw holes the bolt guide hole and the lift or thumb piece slot hole are
formed. One of the perforated ends of the cut off length is next flattened if necessary
and the marginal edges at the said end may be removed so as to reduce its width. The
flat reduced and perforated end being bent or turned down at right angles to the
trough shaped body forms that portion of the bolt case in which the rod or bolt slides
and is guided.
The bolt or rod is arranged at the back of the trough shaped body or case and the
thumb plate is attached to the said bolt or rod and made to work in the slot hole in
the ordinary way.
DL: 00th J. of M 1000
W. T. WHITEMAN,
Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Flush Bolts for Doors and
other Articles.
We ARTHUR GEORGE TONKS of Moseley Street Birmingham in the County of
Warwick Brassfounder and FRANCIS ROBERT BAKER of No. 167 Pershore Road
Birmingham aforesaid Mechanical Engineer do hereby declare the nature of our
invention, and the manner in which the same is to be performed to be particularly
described and ascertained in and by the following statement :-
Our invention has reference to the cases or bodies of flush bolts and consists of the

page_text: improvements hereinafter described in making, the said cases or bodies from sheet
brass or other hard and ductile sheet metal.
By our invention the manufacture of the said cases or bodies is economized; they
are very strong and access of the finger and thumb to the lift or thumb piece for
operating the bolt is readily obtained.
Instead of making the case or body of the flush bolt flat and forming a box or
depression in the said flat case or body of the flush lift or thumb plate or piece of
the bolt to work in as usual we make the greater part of the case or body of a
trough or channel form in which trough cr channel the flush lift or thumb piece of
the bolt works. As the trough or channel has nearly the same width as the case or
body a broad thumb plate can be used with it and as there is no obstruction on
opposite sides of the flush thumb plate or piece in the trough or channel the said
thumb plate can readily be gripped between the thumb and finger for manipulating
the bolt.
The figure of the trough shaped body or case may be varied. We prefer however
to give it either a semi-circular form in cross section or an angular form in cross
section with flat marginal longitudinal edges.
In making the cases or bodies of the flush bolts we form by drawing or by press
tools from sheet metal a long strip having the sectional figure of the case or body
to be made. From this strip lengths are cut transversely and in each of the cut off
lengths the required fixing screw holes the bolt guide hole and the lift or thumb
piece slot hole are formed. One of the perforated ends of the cut off length is
next flattened if necessary and the marginal edges at the said end may be removed
so as to reduce its width. The flat reduced and perforated end being bent or turned
down at right angles to the trough shaped body forms that portion of the bolt case
in which the rod or bolt slides and is guided. The bolt is arranged at the back of
the trough shaped body or case and the thumb plate is attached to the said bolt or
rod and made to work in the slot hole in the ordinary way.
We will now proceed to describe with reference to the accompanying Drawing the
manner in which our invention is to be performed.
Figure 1 represents in side elevation; Figure 2 in plan of upper side; Figure 3
in end elevation and Figure 4 in cross section a flush door bolt the case or body of
which is made according to our invention; Figure 5 represents the lift or thumb
plate or piece of the bolt detached.
The same letters of reference indicate the same parts in the several Figures of the
Drawing.
a is the trough or channel shaped case or body of the flush bolt having a nearly
semi-circular figure in cross section with flat marginal longitudinal edges a² a²; b is
the broad thumb plate or piece by which the bolt or rod is shot and withdrawn.
The said thumb piece b works in the trough or channel of the case or body a and is
flush with its top the stem of the said thumb piece sliding in the guide slot cand
being affixed to the rod or bolt dat d². The sides of the broad thumb plate 6 have
the same configuration as the sides of the trough or channel a and work closely
against the said sides as represented. It will be seen that there is no obstruction
on opposite sides of the flush thumb plate in the trough or channel a hence the
said thumb plate can readily be gripped between the thumb and finger for working
the bolt d. The end of the bolt a works in and is guided by the turned down
end a³ of the body or case a the said end as being made in one piece with the
principal part of the case or body as hereinafter described. A guide hole e for the
bolt d' is made in the end a³ and also a hole for one of the fixing screws to pass
through. A hole 9 is also made in the trough shaped body or case a for a second
fixing screw to pass through.
In making the body or case of the flush bolt we form by drawing a long strip of
metal having the sectional figure represented in Figure 4 and from the said long
strip we cut a length or blank of the kind represented in Figure 6. The trough
shaped blank Figure 6 is pierced with the thumb plate slot c the guide hole e for
the bolt and the fixing screw holes fg and the marginal parts of the trough at one

page_text: end of the blank are cut away as represented in Figure 7. The reduced end of the
blank is next flattened and turned down or bent at right angles to the other part of
the blank as represented in plan and end elevation in Figure 8. The case or body of
the flush bolt represented in Figures 1, 2, 3 and 4 is thereby formed.
Instead of making the case or body of the bolt from a trough shaped strip made by
drawing as described, a flat blank of the kind represented in Figure 9 may be cut
from sheet metal pierced with the required holes and the wide part of the blank
The flat reduced end of
troughed to form the principal part of the body or case.
the blank being bent at right angles to the troughed part the body or case is formed
as before described.
Figures 10 and 11 represent cross sections of flush bolts in which the body or
case a has an angular form in section instead of a nearly semi-circular form.
In the bolt Figure 10 the sides of the trough case are parallel and in the bolt
Figure 11 the sides of the trough case are inclined to one another the thumb
plates 6 having shapes proper to work closely in the angular shaped cases or bodies
as represented.
Having now particularly described and ascertained the nature of our inven-
tion and the manner in which the same is to be performed we declare that we
claim as our invention of "Improvements in the manufacture of flush bolts for doors
and other articles" :-
Making the principal part of the cases or bodies of flush bolts of a trough or
channel form preferably nearly semi-circular or angular in cross section the trough
or channel of the said cases or bodies receiving the flush lifts or thumb pieces of the
bolts the said trough or channel shaped cases or bodies being made either from drawn
strips of sheet metal having the sectional figure of the cases or bodies to be made or
from flat blanks of sheet metal fashioned by press or shaping tools substantially as
herein before described and illustrated in the accompanying Drawing.
Dated this 15th day of February 1890.
W. T. WHITEMAN,
Agent for the Applicants.