IMPROVEMENTS IN WINDOW SASH FASTENINGS
Year: 1879

page_text: LETTERS PATENT to William Gibson, of Aston, near Birmingham, in the County
of Warwick, Manager of Works, for the Invention of "IMPROVEMENTS IN
WINDOW SASH FASTENINGS."
Sealed the 3rd February 1880, and dated the 4th September 1879.
PROVISIONAL SPECIFICATION left by the said William Gibson at the
Office of the Commissioners of Patents on the 4th September 1879.
WILLIAM GIBSON, of Aston, near Birmingham, in the County of Warwick,
Manager of Works. IMPROVEMENTS IN WINDOW SASH FASTENINGS."
"
My Invention consists of the improvements in window sash fastenings, herein
after described, whereby great security is given to the fastenings, and the tampering
with the fastening from the outside of the window is prevented.
My improvements are applicable to window sash fastenings of various kinds, but
I will describe my improvements in connection with an ordinary sash fastening
consisting of an arm on the meeting rail of the upper sash engaging under a fixed
curved catch or arm on the meeting rail of the lower sash.
To the end of the plate on the meeting rail of the lower sash, by which the
curved arm or catch is carried, I attach a spring, the said spring being in the same
or nearly the same plane as the said plate, that is, nearly in the same plane as the
top of the meeting rail of the lower sash. The free end of this spring projects about
half way along the edge of the plate and carries an incline having a thumb plate.
When the arm of the fastening is turned from the meeting rail of the upper sash
and made to pass under the catch on the meeting rail of the lower sash it passes
over the incline on the end of the spring, depressing the said incline. The said
arm in assuming its fastening position passes over the said incline, which, by the
action of its spring, snaps into its normal position and prevents the return of the
arm and the separation of the two parts of the fastening. The arm cannot be
pressed back while the incline. is in the position last described and the window
consequently cannot be unfastened by a knife or other instrument inserted between
the meeting rails of the two sashes.
In order to unfasten the sashes the incline must be depressed by. pressure on the
thumb plate, when the arm can be turned from off the meeting rail of the lower
sash. That part of the underside of the arm which, when the said arm is in its
fastening position, crosses the spring may have a recess, in which the spring, when
it is in its raised position, engages.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Gibson in the Great Seal Patent Office on the 17th February
1880.
:
WILLIAM GIBSON, of Aston, near Birmingham, in the County of Warwick,
Manager of Works. · ** IMPROVEMENTS IN WINDOW SASH FASTENINGS."
My Invention consists of the improvements in window sash fastenings, herein
after described, whereby great security is given to the fastening and tampering with
the fastening from the outside of the window is prevented.
My improvements are applicable to window sash fastenings of various kinds, but
I will describe my improvements in connection with an ordinary sash fastening
consisting of an arm on the meeting rail of the upper sash engaging under a fixed
curved catch or arm on the meeeting rail of the lower sash.
To the end of the plate on the meeting rail of the lower sash, by which the
curved arm or catch is carried, I attach a spring, the said spring being in the
same or nearly the same plane as the top of the meeting rail of the lower sash.
The free end of this spring projects about half away long the edge of the plate and
carries an incline having a thumb plate. When the arm of the fastening is turned
from the meeting rail of the upper sash and made to pass under the catch on the
meeting rail of the lower sash it passes over the incline on the end of the spring,
depressing the said incline. The said arm in assuming its fastening position passes
over the said incline, which, by the action of its spring, snaps into its normal posi-
tion and prevents the return of the arm and the separation of the two parts of the
fastening. The arm cannot be pressed back while the incline is in the position last
described and the window consequently cannot be unfastened by a knife or other
instrument inserted between the meeting rails of the two sashes.
In order to unfasten the sashes the incline must be depressed by pressure on the
thumb plate, when the arm can be turned from off the meeting rail of the lower
sash. That part of the underside of the arm which, when the said arm is in its
fastening position, crosses the spring may have a recess in which the spring when
it is in its raised position engages.
I will now proceed to describe with reference to the accompanying Drawing the
manner in which my Invention may be performed.
Figure 1 represents in plan and Figure 2 in side elevation a window sash
fastening constructed according to my Invention, the two parts of the fastening
being represented engaged together and the safety catch fixing the arm of the
fastening in its locked position.
Figures 3 and 4 represent in plan and side elevation the fastening after the
jointed arm has been released from or is about to engage with the shoulder of the
incline of the safety catch.
Figures 5 and 6 represent a modification of the fastening as herein after
explained.
The same letters of reference indicate the same parts in Figures 1, 2, 3, and 4.
a is the meeting rail of the upper sash to which the part c of the fastening is
affixed, and b is the meeting rail of the lower sash to which the other part & of the
fastening is affixed. The part c of the fastening carries the usual jointed arm e and
the other part & the curved catch f under which the arm é passes to fasten the two
sashes together. The fixing or foundation plate.d on the meeting rail b is extended
outwards at d², the part projecting from the edge of the meeting rail and con-
stituting a bearing to which the end of the strong spring g is attached, the said
spring being situated nearly in the same plane as the plate d. The free end of the
spring g carries an incline h having a thumb plate i for depressing the said incline.
The spring g, its incline h, and thumb plate i, constitute a spring catch which,
when at liberty to move, takes the raised or normal position represented in the
Drawing

page_text: The free end of the jointed arm e of the fastening is prolonged at e³ beyond the
knob or head e³, by which the said arm is moved, the said prolonged part e³ con-
stituting a tooth for engaging with the shoulder h of the incline of the spring
catch. That part of the tooth or prolonged parte of the arm e which is presented
to the incline h of the spring catch is bevilled, as represented in the edge views,
Figures 2 and 4. When the arm se of, the fastening is turned on its joint for
fastening the sashes the said arm as it passes under the fixed catch f on the meeting.
rail b causes the bevilled edge of the tooth or projecting end e² of the said arm e to
bear against the incline h of the spring catch, as, seen in Figures 3 and 4. The
continued motion of the arm e to complete the fastening of the sashes causes the
tooth or projecting end e³ of the said arm to pass over and depress the incline hand
its spring g, and when the arme has reached the fastening position, Figures 1.
and 2, the elasticity of the spring g lifts the incline / into its normal position and
its shoulder h snaps in front of the tooth or projection e³ of the said arm and
prevents its return, as seen in Figures 1 and 2. The arme of the fastening is
thereby locked or fixed in its fastening position by the spring catch g, h, i, and the
separation of the two parts of the fastening is prevented so long as the spring
catch occupies the position represented in Figures 1 and 2.
In order to unfasten the sashes the thumb plate i is pressed down so as to depress
the shoulder h³ of the incline h below the tooth e2 of the arm e.
The arm e is
thereby released and may be turned from off the meeting rail b of the lower sash in
the ordinary way.
.
Figure 5 represents in plan and Figure 6 in side elevation, partly in vertical
section a modification of the fastening already described. In the modification
represented in Figures 5 and 6 the projecting end e* of the jointed arm e of the
fastening has an oblong figure given to it and is furnished with an opening e³ for
receeiving the rounded tooth or incline h* on the spring catch. The inner face e of
the catch end e of the arm e is bevilled, as seen in Figure 6, in which Figure 6 the
spring g, the rounded tooth or incline h*, and the thumb plate i of the catch, and
the catch end of the arm e are represented in section taken on the dotted line k, k,
Figure 5. When the arm e is turned into its fastening position the inclined part e
of the catch end of the said arm acting upon the rounded tooth or incline h¹ of
the spring catch depresses the said tooth or incline, and when the opening e' in the
catch end of the arın has been brought opposite the said tooth or incline h* the
latter snaps into the said opening by the action of the spring g and fixes or locks
the arm & in its fastening position, as best seen in Figure 6. The releasing of
the spring catch preparatory to the turning back of the arm e for unfastening the
sashes is effected by depressing the thumb plate i so as to withdraw the tooth h¹
from the opening e5 in the end of the arm e. A stop on the side of the meeting
rail b may be used to prevent the catch being depressed too far in the act of
releasing the jointed arm e.
As the spring catch is situated at the front of the meeting rail of the lower
sash it cannot be acted upon by a knife or other instrument introduced between
the meeting rails of the two sashes, and as the pressing back of the arm e cannot
be effected until the spring catch is depressed great safety in the fastening of the
sashes is secured.
In order to enable the sash fastening to be operated by one hand only a light
spring may be made to push back the arm e a short distance when it is released
from the spring catch, the said light spring carrying the tooth e* of the said arm
onto the incline h or the opening in the catch end of the arm beyond the tooth h*
(Figures 5 and 6), so that the hand which operated the spring catch may be used
for pushing back the arm e.
My improvements are applicable to all such sash fastenings as have a jointed arm
turning over the meeting rail of the lower sash.
Having now described the nature of my Invention and the manner in which the
same is to be performed, I wish it to be understood that I claim as my Invention
the improvements in window sash fastenings, hereinbefore described and illustrated

page_text: in the accompanying Drawing, that is to say, the combination with that part of the
fastening fixed to the meeting rail of the lower sash of a spring safety catch which,
when the jointed arm of the fastening is turned into its fastening position, engages
with a tooth or projection on or enters an opening in the free end of the said
jointed arm, and thereby locks the said arm in its fastening position, the said spring
catch and the end of the jointed arm with which it engages being constructed and
operating substantially as described and illustrated.
In witness whereof, I, the said William Gibson, have hereunto set my hand
and seal, this Thirteenth day of February, in the year of our Lord One
thousand eight hundred and eighty.
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
WILLIAM GIBSON. (L.S.)