Improvements in Latch-locks.
Year: 1890

page_text: Date of Application, 25th Nov., 1890-Accepted, 27th Dec., 1890
COMPLETE SPECIFICATION.
Improvements in Latch-locks.
1, DUNCAN EDMUND GRANT, of Quebec, in the Province of Queboc, and Dominion
of Canada, Manufacturer, do hereby declare the nature of my invention for IMPROVE-
MENTS IN LATCH-LOCKS, 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 an improvement in latch-locks, and has for its object to
provide a lock which can be fitted entirely with an auger, and thereby obviate the long
and troublesome operation of mortising.
A further object of the invention is to economize in material by combining in one
lock the properties of a latch-lock, a dead-lock, and a bolt.
The invention consists in the novel construction and combination of the several
parts, as will be hereinafter fully set forth, and pointed out in the claims.
Reference is to be had to the accompanying drawings, forming a part of this
Specification, in which similar letters and figures of reference indicate corresponding
parts in all the views.
Figure 1 is a partial elevation of the inner side of a door, illustrating the
application of the lock.
Fig. 2 is a side view of the lock with one casing-section removed, showing the
working parts as they are when the bolt is in its normal position.
Fig. 3 is a longitudinal horizontal section taken on lines 3 3 of Figs. 2, 4, and 6.
Fig. 4 is a back end view of the lock introduced into a door.
Fig. 5 is a transverse section on lines 5 5 of Figs. 2 and 3, the lock being in
the door.
Fig. 6 is a transverse section on lines 6 6 of Figs. 2 and 3.
Figs. 7 and 8 are side views of the bolt-locking plates employed.
Fig. 9 is a partial vertical section through the rose, bolt-handle, and stop-plates.
Fig. 10 is a back view of the rose, with handle and both stop-plates in position.
Fig. 11 is a side elevation of a sleeve utilized in locking the bolt from the outside
of the door.
Fig. 12 is an end view of the said sleeve and a plan view of the spring employed in
connection therewith.
Fig. 13 is a central longitudinal section through the said sleeve..
Fig. 14 is a front view of the crank and its rose, used for locking the door from
the inside.
Fig. 15 is a back view of said device.
Fig. 16 is a section of the same on line 16 of Figs. 14 and 15.
Fig. 17 is a side view of the bolt.
Fig. 18 is a transverse section of the bolt on line 18 of Fig. 17.
Fig. 19 is a back view of the rose used in connection with the bolt-handle, showing
slot in which the stop-plates slide.
Fig. 20 is a detail view of the stop-plates used in connection with the rose.
Fig. 21 is a plan view of the front plate, which may be employed in connection
with the lock.
Figs. 22 and 23 are a back view and a side elevation, respectively, of the racks
adapted to slide in the groove of the bolt.
Fig. 24 is a front view of the key-plate, and
Fig. 25 is a longitudinal section of the same.
The lock is essentially circular in cross-section, and may be made of any desired
diameter; but in practice it is found that the diameter of one inch is the proper size
for the majority of room-doors, and admits of the use of a spindle-pinion capable of
withdrawing the bolt the required distance without more than about a quarter-turn of

page_text: the handle. In very small doors of, for instance, one inch or less in thickness, from
which the auger would remove too much wood, the lock is fitted by mortising, for
which purpose it is made thinner without the exterior projection 45, and instead of
the circular front plate and screw-thread of the anger-lock is supplied with a front
plate of the style shown in Figs. 1 and 21. The object of the rounded ends of the
plate shown in Fig. 21 is to enable it to he fitted with an auger,
The dotted lines 13 indicate the circles cut by the auger, the triangular sections 14
being all that it is necessary to remove with a chisel.
The lock illustrated is of the standard size, and the casing is made in two longi-
tudinal sections A and B, as shown in Figs. 4 and 6. For the usual front plate is
substituted a circular front plate of slightly larger diameter than the lock, and a
screw-thread is produced upon the upper end of the casing and the inner edge of the
front plate beveled, as shown, respectively, at 10 and 11 in Fig. 2. By thus threading
the casing it can he screwed into the auger-hole, heing turned by the projecting
head of the bolt by means of a wrench or equivalent device, and the length of the
thread is made such that when the circular front plate comes flush with the edge of
the door the bolt will be in its proper position.
The bolt 15 is held to slide within the casing, which bolt, as illustrated in Figs. 17
and 15, is essentially rectangular in cross-section, being reduced in depth at both ends,
forming shoulders 16 and 17 and 16 and 171, and the head is beveled in the usual
manner at the extremity projecting beyond the front of the casing. In the centre of
the bolt a slot 18 in two diameters is produced extending through from side to side,
and at the inner end in each side face of the bolt a longitudinal channel 19 is
produced, as shown in Fig. 17, the top and bottom edges being also each provided
with a longitudinal groove 20, as illustrated in Fig. 18. In each of the grooves 20
of the boli a rack 21 is loosely fitted, the feeth whereof face inward, as shown in
Fig. 2, and the side walls of the bolt-slot 18 are concaved at or near the centre on one
side of the bolt only, to permit of the introduction of the spin-lle-pinion wheel 22,
which operates the racks, as illustrated in Figs. 2 and 5.
Each rack 21 is provided with a T-head 23 at one end, the members whereof bear
against the shoulders 16 and 17 of the bolt. The head of the bolt is normally held
beyond the end of the casing by a spring 24, located in the narrow portion of the
slot 18, having a bearing upon the bolt at one end and upon a post 25 at the other
end, which post or off-set is formed on casing-section B, and passing through the
bolt-slot 18 is secured to casing-section A. The two sliding racks are of precisely the
same pattern and size, and the object of having two racks is to allow the door to be
opened by turning the handle in either direction, as when one rack is engaged in
withdrawing the holt the other rack merely slides forward inoperatively in its groove
and the space 25", intervening between the bolt-shoulders 16 or 17 and the front end
of the lock-case.
The pinion 22 is provided with trunnions 26, having a rectangular bore through
which the spindle 27 passes, and the rear face of each trunnion is flattened, as shown
at 28 in Fig. 5, for a purpose hereinafter stated.
The spindle 27, Figs. 2 and 3, is the usual square one of the same size throughout,
but without screw-holes, and the handles 29, Figs. 1 and 9, are of the usual form,
except that the portion which enters the rose 30, Fig. 9, is reduced in diameter and
provided with a peripheral groove 31 a short distance from the end, and a lug or
projection 32, extending at a right angle from one side of the inner end, as shown in
Figs. 9 and 10. The rose 30 is of the ordinary size and shape, and is provided with
a groove 33, Fig. 19, cut in one wall of the opening, through which the handle
passes to admit of the passage of the handle projection 32, and in the back of the
rose a broad shallow channel or slot 34, Fig. 19, is produced, extending from side to
side, and two studs 35 are driven or otherwise inserted in the back within the slot or
channel, as best shown in Figs. 10 and 19.
'
The slot or channel 34 is adapted to receive a stop-plate 36, Figs. 10 and 20, in two
sections B and B³, as best shown in Fig. 20. In the inner end of each section a semi-
circular opening or recess 37 is formed, and at each side thereof a smaller opening 38

page_text: of similar character is made. When the rose has been secured to place, the spindle
passed through the lock, and the handle pushed into position, one section of the stop-
plate is slid into the rose-channel 34 from above and the other from below, until they
enter the handle-groove 31 surrounding the handle-shank and resting against the
studs 35, to the contour of which they conform, as shown in Figs. 9 and 10. Each
plate-section is then held in position by a screw, and the handles are securely locked
in place ther-by, and are rendered free from the looseness and rattle of the usual
screw-and-washer style of fastening, and the spindle, moreover, requires no
adjustment.
When the handle is turned, the pinion 22 moves back one of the racks, which,
through its cross-head hearing on the shoulders of the bolt, draws the latter back
until the projections 32 of the handles strike one or the other of the studs 35 upon
the handle-rose, and further movement of the handle in that direction is stopped.
The object of limiting the movement of the handles is to prevent any greater stress
being put upon the teeth of the racks and pinion than the power of the spring 24,
which might happen if the movement of the bolt was limited instead of that of the
handles. When the handles are released, the spring 24 pushes forward the bolt 15,
and the bolt draws forward with it the rack which was active in pulling it back, and
thereby revolves the pinion 22, causing the latter to slide the other rack back until its
cross-head 23 comes into contact with the shoulders of the advancing bolt, whereby
both racks act equally to prevent further movement of the bolt, and the pinion-wheel
is held by them in such a position that the flattened sides of its trunnions are
presented to the locking-plates.
In connection with the bolts two locking-plates 39 and 40 are employed, the
plate 39 being adapted to prevent the bolt from moving when the door is locked from
the outside, and the plate 40 when it is locked from the inside. The locking-plates
slide in the side channels 19 of the bolt, and are carried by said bolt as it moves.
The bodies of the plates, or those portions in contact with the bolt, are identical in
construction, being rectangular and provided at the outer end with heads 41, capable
of entering the central slot 18 of the bolt, and provided with convex rear edges con-
forming to the concavity of the rear wall of that slot, as best shown in Fig. 2, and at
the rear end of the hoilies cross-bars or vertical projections 42 are formed, which
come in contact with the rear shoulders of the bolt, if the bolt be forced from in front.
The locking-plate 39 is provided in the rear with a narrow tongue 43, extending
from the rear end of the body in the same plane with it, and in the locking-plate 40
for the tongue is substituted a link 44, capable of sliding in the casing and through
which passes the locking device of plate 39. The locking-plates might be made of
one piece with the bolt if it were not that in that ease, if, when the bolt had been
blocked by the door being locked from either the outside or the inside, an attempt to
open the door by turning the handle was made, considerable force might be brought
to bear upon the teeth of the rack and pinion, sufficient, possibly, to break them. To
avoid that danger and prevent the teeth at any time having to sustain any greater
pressure than that of the spring 24 the locking-plates are provided and their action
is as follows: When the bolt is pushed forward by the action of the spring 24, the
heads 41 of the locking-plates 39 and 40 are caught by the rear end wall of the bolt-
slot 18 and pressed against the flattened surfaces 28 of the pinion-trunnions 26.
Then when the door is locked either from the inside or the outside the inner or rear
end of one or other of the locking-plates is blocked in a manner to be hereinafter set
forth, and the handles in consequence cannot be turned, and if an attempt be made
to turn the handles the pressure will not fall upon the teeth of the racks and pinion,
but upon the trunnions of the pinion and the locking-plate 39 or 40, as the case may
be, and both of them are amply strong enough to sustain any pressure that can be
exerted by means of the handle; but it from the slightest defect in workmanship
the locking-plates were not a perfectly-accurate fit of the distance between their
locking devices at one end and the flattened side of the pinion-trunnion at the other
end, a very slight movement of the pinion would be possible when the door was locked,
and as the diameter of the pinion is larger than that of its trunnions it would travel

page_text: qaicker, and the pressure would in that case fall on the teeth of the pinion and rack
instead of on the trunnion and locking-plate. To prevent the possibility of that
occurring the hodies of the locking-plates are made about an eighth (4) of an inch
longer than the grooves of the bolt in which they slide, so that if there is any
movement of the pinion when the door is locked the bolt will move slightly back until
the trunnion comes in contact with the end of the locking-plate, when all the pressure
beyond the power of spring 24 will be transferred to the locking-plate, from which it
will be seen that neither by means of the handle nor by forcing the bolt from in front
can any greater pressure he brought to bear on the teeth of the pinion and racks than
that of the spring 24.
In order to effect the locking of the bolt from the outside, a key is employed and
off-sets 45 and 46 are respectively formed upon the sections B and A of the casing
near the rear, which offsets are in horizontal alignment, as shown in Figs. 3 and 6.
The wards of the key, which may be varied indefinitely, are turned upon the opposite
faces of these offsets, as shown at 47 in Fig. 6, and a slot 48 is cut in the outer offset
across the entire diameter of the circle described by the key to admit of the key being
withdrawn after having made a half-turn, and to render picking more difficult the slot
is carried a little farther down in the offset 46 than the wards. Across the said
offset 46 of the end attached to the casing and parallel with the casing a diametrical
opening 49 is produced, through which opening the tongue 43 of the locking-plate 39.
passes when the lock is open and the bolt drawn backward.
A sleeve 50 is loosely mounted upon the offset 46 and upon the inner portion of the
offset 45, being free to turn thereon, which sleeve is illustrated in detail in Figs. 11, 12,
and 13. Near the end of the sleeve turning upon the offset 45 an interior circum-
ferential rib 51 is formed, which enters the space between the contiguous faces of the
offsets, and is provided with two diametrically-opposite notches 52, capable of
registering with the key-slot in the offsets. When the key is introduced into the slot
in the offsets, it passes through one or the other of the notches 52, according as it is
inserted turned up or down, and when it is turned it presses against the end of the
rib and carries the sleeve around with it until motion is arrested by the lug 53, foruied
upon the periphery of the sleeve, coming in contact with the shoulder 54 of the casing
opposite that from which it started, as shown in Fig. 2. An opening 56 is produced
in the sleeve at the end next case B slightly larger than the opening 49 in the offset 46,
and when the door is unlocked this opening 56 is on the side next the bolt, whereby
the tongue of the locking-plate 39 may pass through the said offset 46 its entire length
as the bolt is drawn back; but when the door is locked by giving the sleeve a half-
turn the opening 56 is carried to the opposite side of the offset and the entrance of
the tongue into the offset-opening is effectually blocked as the plain side of the sleeve
is presented to it.
In order to prevent any accidental movement of the sleeve by the shaking or
slamming of the door, a small flat spring 57, Fig. 12, with a hole in its centre is
fitted over a second lug 58 upon the sleeve. This spring is carried around by the
sleeve, when it is moved by the key and its ends pressing against the surrounding
portion of the casing, as shown in Fig. 2, it holds the sleeve fast in whatever position
it is left by the key.
The locking of the door from the inside is effected by giving the crank 59 (illustrated
in Figs. 14, 15, and 16) a half-turn to the left. The crank is provided with a square
shaft 60, which shaft is inserted in the square bore of an externally-threaded cylindrical
block 61, screwed into section B of the casing, as best shown in Fig. 3, and the thread
being given a quarter-inch pitch the cylindrical block 61 can be advanced or withdrawn
an eighth () of an inch by giving the crank a half-turn to left or right. The
threaded block 61 is of the same length as the width of section B of the lock-casing,
whereby when its inner end is flush with the inner face of casing-section B a space 62
intervenes between the end of the block and the casing-section A, into which space,
when the door is unlocked, the link portion 41 of the locking-plate 40 slides, its link
shape enabling it to pass on either side of the sleeve 50. By advancing the block 61
about an eighth of an inch by a half-turn of the crank when the bolt. 15 is in its normal

page_text: The
position, the cylindrical block 61 enters the space 62 and effectually prevents the link-
shaped locking-plate 40 from moving, and so locks the door from the inside.
portion of the crank-shaft which moves in the rose is round, and has at its outer end,
projecting at right angles on opposite sides, two lugs of different size and length, as
shown in Figs. 15 and 16, while the portion extending beyond the lugs is squared to
suit the bore of the cylindrical block 61. The rose 63 has in the back a central
recess 64, (shown in Figs. 15 and 16,) and a circular opening in the centre of the
diameter of the round portion of the crank-shaft, through the walls of which,
diametrically opposite each other, are cut slots corresponding in size and shape to the
lugs or projections on the crank-shaft, so as to admit of their passage through the
rose. When the crank-shaft has been passed through the rose, it is given a quarter-
turn, and the studs 67, Fig. 15, are then screwed into place. By means of them the
movement of the crank is limited to half a turn, while its projecting lugs are prevented
from coming opposite the slots by which they entered, and in consequence the crank-
shaft cannot be withdrawn from the rose. The crank-shaft is then inserted in the hore
of the cylindrical block 61, and the rose secured in its proper position. This shaft,
like the handle-shaft, possesses the advantage of requiring no adjustment, as the
shaft merely enters more or less into the bore of block 61, as the doors may vary in
thickness.
For doors which have pivoted windows or fan-lights above them-such as most
hotels and some dwelling-house bedroom-doors have a set-screw 68, Figs. 14 and 16,
is fitted in the end of the crank, which when the door is locked inside may be intro-
duced into the aperture 69 in the rose as a security against the crank being turned
by any person on the outside by means of anything inserted through the window
above. A single knob may also be used in place of the crank, though it will not indicate
as the crank does by its position when the door is open and when it is closed.
The key-plate shown in Figs. 24 and 25 is designed to be fitted with an auger.
is bored for a portion of its length of the same diameter as the offset 45, over which
it fits and forms a guide for the key.
Among the many advantages of a lock constricted as above, it may be stated that
it can be fitted with great rapidity, ease, and solidity to a door, and that no separate
holt is required, as is necessarily used in connection with bedroom-doors when the
present style of lock is employed, since in my improved form of lock when the door is
locked from the inside it cannot be opened from the outside, even with its own key.
A further advantage consists in the fact that the lock can be used indiscriminately as a
right or as a left hand lock without the necessity of any alteration. The small
amount of material required in its construction and the small amount of space it
occupies may also be cited as advantages, and it will also be observed that the handles
are securely fastened without any screws to work loose or washers to rattle, as they
frequently do in the present style of fastening.
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:-
1. In a late-lock, the combination of a holt having side shoulders near both ends
with racks sliding in grooves in the bolt, and each provided with a cross-head at one
end adapted to bear on the forward shoulders of the bolt, and a spindle-pinion meshing
with the racks, by the revolution of which either to the right or left hand the bolt
can be withdrawn, substantially as described.
2. In a latch-lock, the combination of a bolt having a central slot and top and
bottom and si le longitudinal grooves with a spring contained in the central slot, and
bearing with one end on the bolt and with the other on a projection or off-set of the
of the casing, which passes through the said slot and on which the bolt slides, racks
sliding in the top and bottom grooves of the bolt and each having at one end a cross-
head adapted for contact with the forward shoulders of the bolt, and a spindle-pinion
held to revolve in the central slot of the bolt and meshing with th: sliding rack;
substantially as shown and described.

page_text: 3. In a latch-lock, the combination of a spring-actuated bolt, racks sliding in the
top and bottom grooves of said bolt, and a pinion capable of operating the racks, with
'a rectangular spindle passing through the pinion, a handle or handles having the shank
portion provided with a central rectangular bore adapted to receive the said spindle,
and having a lug projecting at a right angle from one side of the inner end, and a
rose having a central circular bore with a slot cut through the wall of it for the
passage of the handle-shank and its projecting lug, and also having on the back two
studs so placed as to come in contact with the lug of the handle-shank as it revolves
and so limit the revolution of the handle and pinion-wheel to the required distance,
substantially as and for the purpose described.
4. In a latch-lock, the combination of a spring-actuated bolt, racks held to slide in
said bolt, a pinion for operating the racks, and a spindle passing through said pinion,
with a handle or handles the shank portion of which is made in two diameters having
near the inner end of the shank a peripheral groove, a rose having a central circular
bore adapted to receive the portion of the handle-shank of smaller diameter and having
across the back a broad shallow channel, and a stop-plate in two sections which slide
in said channel and are recessed at the inner ends so as to render them capable of
entering the peripheral groove on the shank of the handle and of surrounding the
shank and the rose-studs on either side of it for the purpose of securing the handle to
the rose, substantially as shown and described.
5. In a latch-lock, the combination of the bolt with two locking-plates carried in
parallel grooves on opposite sides near the rear of said bolt and capable of a slight
longitudinal movement in the grooves of said bolt, substantially as described.
6. In a latch-lock, the combination of a bolt, sliding racks for withdrawing said
bolt, and a spindle-pinion for operating said racks having its trunnions flattened on
one side, with a locking plate, or plates adapted to prevent the movement of the
pinion when the door is locked by coming in contact at the forward end with the
Hattened side of the pinion-trunnions and at the rear end with their respective locking
devices, substantially as and for the purpose described.
7. In a latch-lock, the combination of a spring-actuated bolt having top and bottom
and side grooves and side shoulders near both ends, racks sliding in the top and
bottom grooves of said bolt, a spindle-pinion meshing with said racks and having its
trunnions flattened on one side, and a locking-plate carried in the inner side groove of
the bolt having a rectangular body fitted to slide in said groove, a cross-head at each
end of the body and a tongue extending in the rear in line with the body, the forward
cross-head being adapted to slide in the central slot of the bolt and come in contact on
one side with the rear walls of said slot and on the other side with the flattened side
of the pinion-trunnion, the rear cross-head adapted to come in contact with the rear
shoulders of the inner side of the bolt, when the bolt is forced backward, and the
tongue adapted to come in contact with the revolving sleeve, forming its locking
device when the door is locked, or to enter said sleeve when the door is unlocked, with
an apertured sleevo capable of being revolved by a key so as to present the plain side
of the sleeve to contact with the tongue of the locking-plate when the door is locked
and the apertured side for the entrance of said tongue when the door is unlocked,
substantially as shown and described.
8. In a latch-lock, the combination, with a spring-actuated bolt, of racks sliding in
longitudinal grooves in top and bottom of said bolt, a pinion for operating the racks
held to revolve in the central slot of the bolt and having its trunnions flattened on one
side, a locking-plate carried in the inner side groove of the bolt, having a forward
cross-head capable of movement in the central slot of the bolt and fitted to come in
contact with the rear wall of said slot on one side and the flattened side of the pinion-
trunnions on the other side, a rear cross-head adapted for contact with the rear
shoulders of the inner side of the bolt, and a tongue projecting horizontally from the
rear cross-head in line with the body of the plate, offsets formed on the outer and
inner sections of the casing in horizontal alignment with each other having wards cut
in their opposing faces, a diametrical slot cut through the entire length of the outer
offset and a portion of the inner one, the inner one also having through its base

page_text: parallel with the casing a diametrical opening for the passage of the tongue of the
locking-plate, a sleeve or cylinder mounted to turn on the offsets, having an opening
on one side capable of registering with the opening in the inner offset, and an internal
circumferential rib which fits between the opposing faces of the offsets, with two
notches cut in it diametrically opposite each other capable of registering with the key-
slot in the offsets for the admission of the key-bit, also having two projecting lugs of
different sizes, the larger one of which limits the movement of the sleeve to half a
turn by coming in contact with one or other of the shoulders formed on opposite sides
of the inner casing while the smaller one secures the spring in its place, a flat spring
fitting over said smaller lug by means of an opening in the centre and pressing
against the surrounding casing for the purpose of preventing accidental movement of
the sleeve, and a key by means of which said sleeve is revolved so as to present its
plain side to contact with the tongue of the locking-plate when the door is locked and
the apertured side for the entrance of said tongue when the door is unlocked,
substantially as described.
9. In a latch-lock, the combination of a spring-actuated bolt provided with a
central slot and having longitudinal grooves on top and bottom and both sides, a rack
held to slide in each of the said top and bottom grooves, having a cross-head at one
end adapted for contact with the forward shoulders of the bolt, and a pinion meshing
with the said racks and having its trunnions flattened on one side, with a locking-
plate comprising a rectangular body adapted to slide in the outer side groove of tlie
bolt, a forward cross-head capable of sliding in the central slot of the bolt and adapted
to come in contact on one side with the rear wall of said slot and on the other side
with the flattened side of the pinion-trunnions, a rear cross-head suited for contact
with the rear shoulders of the outer side of the bolt, and a link-shaped projection in
rear in line with the body of the plate fitted to pass on either side of the locking
device of the other locking-plate and slide in the vacant space between the outer and
inner sections of the casing when the door is unlocked, an exteriorly-threaded
cylindrical block screwed in the inner section of the casing and provided with a
rectangular bore for the entrance of the crank-shaft, by means of which it can be
advanced so as to prevent the movement of the locking-plate when the door is locked
from the inside by filling up the vacant space in which said plato moves, or withdrawn
to permit the movement of the locking-plate when the door is unlocked, a crank
having that portion of its shaft which moves in its rose round in form, with, projecting
from it at right angles on opposite sides, two lugs of different sizes and shape, while
the portion of the shaft extending beyond the rose is rectangular and adapted to enter
the bore of the cylindrical block for the purpose of turning it, and a rose having a
central circular bore with slots of the same size and shape as the lugs on the crank-
shaft cut through the walls of it on opposite sides for the passage of the crank-shaft
and its lugs, a central circular recess in the back in which the said lugs revolve, and
two studs secured on opposite sides of the recess for the purpose of limiting the move-
ment of the crank to half a turn and preventing the lugs from coming opposite the
slots by which they passed through the rose, substantially as shown and described.
Dated thi
day of November 1900