Improvements in the Locks of Window Sashes.
Year: 1893

page_text: Date of Application, 3rd July, 1893
Complete Specification Left, 2nd Apr., 1894-Accepted, 5th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in the Locks of Window Sashes.
:
I, HENRY GOODRICK LAZENBY 26 Norwood Road Herne Hill London S.E.
Architect, do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in the locks of window sashes, and consists
more particularly in an arrangement of the different parts of the lock whereby the
key is retained in the lock so long as the lock bolt, the protrusion of which locks
the sashes in the desired position, is retracted, and renders it impossible to withdraw
the key from the lock without protruding the bolt.
The lock itself has a case of suitable form, within which at one end is pivotted
the operative bolt of the lock. This bolt is so shaped that a partial revolution on
its pivot protrudes its operative nose through an opening in the case, and further,
that either when protruded or retracted it completely fills the hole through which
it works. On the back of the bolt are formed teeth adapted to gear with a worm
cut on the end of a cylinder which is pivotted longitudinally in the lock case, the
other end of which extends to the front or keyhole plate of the lock.
In the portion of the cylinder between the worm and the front plate is formed a
helical groove. A keyhole is formed in a rigid part of the lock, and extends from
the front plate parallel with the axis of the abovementioned cylinder, the side next
the latter being slotted to admit of a suitably shaped stud on the key engaging with
the helical groove in the cylinder.
The action is as follows:-On inserting the key into the keyhole, the stud on
the end of the key, projecting through the slot in the side of the keyhole, engages
with the helical groove in the cylinder, causing the latter to revolve on its axis,
and by means of the worm gear rotating the bolt so that its operative nose is
retracted. On withdrawing the key the converse movements take place.
Dated this Third day of July 1893.
.
COMPLETE SPECIFICATION:
Improvements in the Locks of Window Sashes.
I HENRY GOODRICK LAZENBY of 26 Norwood Road, Herne Hill, London,
Architect 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 improvements in the locks of sliding window sashes, and
consists in a formation and arrangement of the parts of the lock whereby the key
is retained in the keyhole until the bolt of the lock is in the protruded or locked
position, and whereby the aperture in the lock case through which the bolt works,
is completely closed by the bolt when the latter is in both the locked and unlocked
positions.
In order that my invention may be thoroughly understood, reference is made
to the accompanying drawings, which are to be read with this Specification and
considered as part thereof.
Fig. 1. is a longitudinal section of a sash lock constructed according to this
invention.

page_text: Fig. 3. is an elevation of the front or keyhole end of the lock.
Fig. 4. is a transverse section of the lock, taken on the line A-A.
Figs. 5. and 6. are front and side elevations respectively, of the key adapted for
use with this lock.
:
The lock has a case C of suitable form, having flanges E forming a face plate,
through which screws may be passed for attaching the lock to the woodwork of a
sash frame.
The bolt B of the lock is pivotted at P, within one end of the case, and is shaped,
as shewn in Fig. 1, so that a partial revolution on its pivot, protrudes or retracts
its operative nose B¹ through an opening in the case. By the shaping and relative
arrangement of bolt, pivot, and aperture, as illustrated in Fig. 1, the aperture in the
case, through which the bolt B works, is closed by the bolt, both when the latter
is in, the locked position, as shewn at B, and when in the unlocked position as
shewn by, the broken lines at B2. When in the unlocked position, the face B³ of
the bolt, is flush with the face C₁ of the lock. On the hub of the bolt are formed
teeth, pins, or their equivalents T, which gear with the worm W, which is formed
on one end of the spindle S, the other end of which extends to the front end of the
lock, and has formed in it the helical groove G.
The spindle S is mounted in a bearing or bearings, with its axis parallel to the
face of the lock and central thereto. The bearing, shewn in the illustrations is a
convenient one, one half being formed in the lock case C,, and the other half in the
back cover D. The spindle is held in position longitudinally by suitable stops.
A keyway K is formed in the lock case, with its axis parallel to that of the
spindle S, and having a slot along its whole length towards the spindle, as shewn in
Figs. 1 and 4.,
·
A guard R may be formed on the front plate F of the lock, containing a circular
space to allow of the rotation of the nib of the key, and a stop T for limiting the
said rotation.
1 J
In a modification of the lock, the guard R may be dispensed with, and the front
plate F made flush, the space for the rotation of the key nib being formed in the
case, at the front end of the keyway, immediately under the front plate. The key-
way and slot may also be made to come direct through the front of lock, so that
the key may enter direct, without any circular movement.
The external keyhole K2 of the lock is formed in the front of the guard R,
and has the centre of its circular part coincident with the axis of the
keyway K.
The key has a plain shank or stem, of such a size as to fit within the keyway K,
and long enough to reach to the bottom of same.
Near the end of the key is a nib or stud, one part of which K³, is square, and
adapted to fit the slot in side of keyway; and the other part of which K*, is
oblique, and adapted to engage with the helical groove G, in the spindle S.
The action of the lock is as follows-The bolt being in the protruded or locked
position; in order to unlock it, the key is inserted in the keyhole K2, and turned
so as to bring its nib, opposite the end of the slot in the keyway, and the end of
the helical groove in the spindle. The key is then to be entered longitudinally
into the keyway, the nib of the key, protruding through the slot, engages with the
helical groove in the spindle S, and rotates the latter, the motion of which is
transmitted by the worm gear to the bolt, which, by the time the key reaches the
bottom of the keyway K, is turned into its unlocked or retracted' position. On
withdrawing the key, the converse motions of spindle and bolt are produced; the
latter being returned to the locked position by the time the key is free of the
keyway. Thus the bolt must be in the locked position before the key can be
disengaged from the lock..
The lock is intended to be mortised into the pulley style of a window frame
having the usual sliding sashes, so that the face C₁ of the lock, is flush with the
face of the pulley style against which the sashes slide; the front plate F being
towards the apartment, and the bolt at the level of the meeting rails of the

page_text: sashes. The bolt, when protruded, engages with suitable recesses formed in the
sashes, thus locking them in position. The lock may also be adapted to lock
horizontally sliding sashes.
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. In a sash lock with pivotted bolt, the formation and arrangement of the bolt,
so that when in both the locked, and unlocked, positions, it closes the aperture
in the lock case, through which it works, substantially as herein illustrated and
described.
2. Operating a sash lock by means of a key having longitudinal motion in a
keyway, and adapted to engage with a helical groove formed in the spindle of the
lock, substantially as herein shewn and described.
3. A sash lock constructed, arranged, and operating, substantially as herein
set forth.
Dated this 2nd day of April 1894.
HENRY GOODRICK LAZENBY.