Improvements in Locks and Latches.
Year: 1899

page_text: Date of Application, 30th Nov., 1899-Accepted, 13th Jan.,
1900
COMPLETE SPECIFICATION.
Improvements in Locks and Latches.
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1, GEORGE HARRY BURROWS, of Wood Street, Willenhall, in the County of
Stafford, Lock and Latch and Brass Furniture Manufacturer, do hereby declare
the nature of this invention, and in what manner the same is to be performer,
to be particularly described and ascertained in and by the following statement:
Lock and latch cases, as heretofore very commonly constructed,
have had the front plates each in the same piece of sheet metal
as the fore and back ends, and the rims have been either formed
separately and riveted to the front plate, or have been formed in
the same piece of sheet metal therewith. In both cases, the cap or back plate is
formed as a separate piece of metal. Forming the rims separately from the front
plates and riveting them thereto, is expensive in manufacture, and the rivets are
liable to give way; and the formation of the rims in the same piece of metal
with the front plate and fore and back ends involves unnecessary waste of metal.
The bridge-pieces which are situated within lock cases have commonly been
formed each in three main portions, namely, a plate which carries the wards and
a pair of side plates or cheeks. The ward plate has first been riveted to the
cheeks, and the cheeks have then been riveted to the front plate of the lock case.
This construction of bridge-piece is expensive, and the riveting between the ward
plate and cheeks is liable to become loose thus tending to allow the structure
to rock and loosen the riveting of the cheeks to the case.
Now, according to the first part of this invention each lock or latch case is
formed in two separate main portions only, one of which comprises the front plate
and the fore and back ends, while the other comprises the cap or back plate and
the rims or sides made in one piece of sheet metal. It is preferred, also, to form
the front plate and fore and back ends to-gether in one piece of metal. It is
preferred to put the two main portions of the case together with the cap and rims
between the fore and back ends. These ends then prevent the cap from moving
endways, or twisting. The cap and rims are prevented from moving sideways by
a stump which is fixed to the front plate, and the two main portions of the case
are secured to-gether by a screw.
In order that this part of the invention may be clearly understood, I will
proceed to describe an application thereof with reference to Figures 1 and 2 of the
accompanying drawings, of which Figure 1 is a longitudinal sectional plan taken
through the centre of a lock or latch case, and Figure 2 a section taken on
linex of Figure 1. A and B are the two separable main portions of the case,
the portion A comprising the front plate a, the fore-end b and the back end c, all
conveniently in one piece of sheet metal, while the portion B comprises the cap or
back plate d and the two rims or sides e made in one piece of sheet metal. When
the portions A and B are put together, the edges of the rim e rest against the
inner face of the front plate, and the ends of the rims and of the cap butt against
the fore and back ends b and c. A screw is shewn as employed for fixing the
portions A and B together, and the stump 7 which carries the lever or levers, or

page_text: tumbler, of the lock or latch mechanism, passes through the back plate d of the
case.
A narrow margin k inwards from the upper and lower edges, respectively, of
the cap plate, is shewn as standing forwards from the face of the main portion of
the cap: This is not at all essential, and is merely to give an appearance of
strength and afford a face for polishing, if required. This method of forming a
fillet along the edge of a cap plate has been practiced heretofore; but, when this
is adopted in connection with this invention, the. rims, of course, join into the
outer edges of the fillets.
According to the second part of this invention, the ward plate and cheeks of a
bridge-piece are formed to-gether in a single piece of sheet metal. The portions
to form the cheeks are bent at right angles to the portion to form the plate,
and the ends of the cheeks are formed with rivets, as usual, by means of which
they are riveted to the case. The avoidance of rivetting between the ward plate
and cheeks renders their connection very rigid, and avoids the tendency of the
cheeks to rock and loosen the connection with their case which constitutes an
inconvenience of the, ordinary construction of bridge-piece. Moreover, the cheeks
do not extend beyond both faces of the ward plate, and thus economy of material
results. Economy of labour results, also, from this construction of bridge-piece.
This part of the invention is illustrated mainly by Figure 3 of the drawings
herewith, which is a flat view of a sheet metal blank cut to the required shape for
the bridge-piece, but, also, by Figures 1 and 2, in which the bridge-piece is shewn
in plan and side elevation, respectively, is the ward plate and h h are the parts
which when bent at right angles to the plate (as shewn by Figures 1 and 2) form
the cheeks. The cheeks are riveted to the case by rivets ; formed at their outer
ends.
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:-
1. A lock or latch case having the cap-plate and rims formed together in
the same piece of sheet metal, substantially as described.
2. A lock or latch case having the back end formed with or permanently fixed
to the front plate, and the cap plate and rims formed together in the same piece
of sheet metal, substantially as described.
3. A bridge-piece for a lock, having the ward plate and cheeks formed together
in the same piece of sheet metal, substantially as described.
Dated this 29th day of November 1899.
STEPHEN WATKINS & GROVES,
Wolverhampton,
Agents for the Applicant.