Improvements in Locks and Latches.
Year: 1889

page_text: Date of Application, 4th Sept., 1889
Complete Specification Left, 24th Mar., 1890-Accepted, 5th July, 1890
PROVISIONAL SPECIFICATION.
Improvements in Locks and Latches.
1. CHARLES GROVES, of Chipwell Green, Willenhall, in the County of Stafford,
Lock Manufacturer, do hereby declare the nature of this invention to be as follows:-
This invention relates to that class of locks and latches, known as detectors.
The object of my invention is to detect when a false key has been introduced, for
the opening of a lock or latch; and which act is indicated, by the true key failing to
act, when the lock or latch is required to be unfastened.
The placing of the parts of the lock or latch in their proper relative positions is
effected, by reversing the direction of motion of the true key.
I will now describe my invention in connection with a padlock.
The casing consists of back and front plates, with an intermediate body-rim between
them, wherein the detector and lock mechanism is enclosed.
To the upper part of the lock, the staple-loop is rearwardly jointed, and with its
fore inside part notched or gapped wherein the bolt is shot, for locking.
The locking bolt forms the fore and cross part, to a sliding plate with guide gaps,
fore and aft, taking upon standing out pins, directed from the inside face of the back
plate.
The underside edge of the said bolt-plate, is gapped in manner proper, for the key
bit, or bits, to act up; whilst the middle of the said plate, has a stump, and a double
gate, with one of the gaps of the gate of an increased length, to facilitate the
returning of the parts to their normal positions, by the back turning of the key, after
the detector has been brought into play by the introduction, of a false key.
the
Hinged to the guide pin, are three or more levers, with their gates taking upon
stump, on the bolt-plate. These levers have the usual springs for keeping them in
their assigned position.
Disposed between the underside of the bolt-plate, is a tumbler lever, normally kept
down, by a spring; and disposed upon the front top side of the said tumbler lever, is
a stump, which takes into the double gate formed within the bolt-plate as aforesaid.
Situated above the tumbler lever, which is the "detector," is an arm or spring,
with a hooked free end, whose function is, to retain the detector in an overshot
position, that is in a position above that part of the gate, which admits the bolt to
be shot.
OPERATION.
On a false key being introduced, for the withdrawal of the shot-bolt, the tumbler
lever stump is raised and their held above the middle of the gate, in the bolt-plate,
and into a detector gap, on the top side, or edge of the said gate, which thereby stops
the bolt from being withdrawn.
Tampering with the lock is now detected, by the true key failing to return the bolt,
which can only be done by the turning of the key in the way.
The true key lifts the levers, and also the stump of the detector to their proper
heights so that the bolt-plate can be moved either to the right or left.
I do not confine myself to the means for holding, or retaining the detector, on it
being raised, above a determinate height, as other means may be employed, other
than an arm, or spring as described.
The double gate as aforesaid is a gate, with gaps top and bottom, and with the
inner top gap longer than the others.

page_text: COMPLETE SPECIFICATION.
Improvements in Locks and Latches.
I, CHARLES GROVES, of Chipwell Green, Willenhall, in the County of Stafford,
Lock Manufacturer, 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:
This invention relates to that class of locks and latches, known as detectors.
This invention has for its object, primarily, to detect when a false key has been
used, in attempting to open a lock or latch.
Such clandestine opening, is indicated by the true key failing to act, when the lock
or latch is required to be unfastened.
The placing of the parts of the lock or latch, in their proper relative positions, is
effected by reversing the direction of motion of the true key.
Figure 1 of the accompanying drawings, represents a four lever detector padlock,
constructed and arranged according to my invention.
The shoot is shown thrown,
and the padlock fastened.
Figure 2 represents a like view as figure 1, but with the four common tumbler
levers, removed, in order to better exhibit the detector means, which are shown in
dotted lines. The said view shows in section, the shoot stump, and also the detector
stump, the former engages with the gaps of the common tumblers, whilst the latter
holds the shoot in position, unless the detector tumbler lever carrying it, is raised into
a coincident position, with the gate of the gap of the shoot.
It may be observed, that the stump of the detector tumbler, becomes coincident
with the gate of the shoot, at the same time that the stump of the shoot, becomes
coincident with the gates of the common tumbler-levers.
Figure 3 represents a like view as figure 2, but showing a false key introduced, and
the detector tumbler lever, lifted thereby, and held in its lifted position, by a bent or
undercut shoulder, disposed above the joint end of the said lever, engaging with,
or being engaged by a sear, in the form of a spring, whose free end is rounded off
into a bulbous end.
This introducing of the false key, places the detector tumbler lever, in such a
position, that its stump is made to pass behind a shoulder of the gap, so as to prevent
the shoot from being reversed, or unlocked.
In order that the parts for the releasing of the detector lever, be clearly shown;
the rear portion of the said lever, is broken away, showing the incline plane or
lump, for releasing the sear, performed by the true key being moved alike unto
when the same is intended to throw the shoot for locking.
Figure 4 represents a portion of figure 3, upon an enlarged scale.
Figure 5 shows a like view as figure 4, with the true key acting upon the
shoot in a direction for locking, whereby the detector tumbler lever, which has
been raised, and held in a suspended position by the false key, is released, by
the incline, which is carried at the back of the shoot, pushing the sear end from
its engagement with the bent.
Figure 6 represents a horizontal section of the mechanism, and padlock casing,
upon an enlarged scale, or upon the same scale as figures 4 and 5.
Figure 7 represents a back elevation of the shoot, showing the inclined lug, for
taking off the holding sear from the detector tumbler lever, (shown separately in
elevation and edge view in figure 8).
Figure 9 represents an ordinary lock, provided with improvements constructed
according to my invention.
a is a padlock casing, consisting of back and front plates, with an intermediate
body rim, disposed between them, and within which said casing, the lock mechanism
is enclosed.

page_text: with the other or free end 63, provided with an inside gap 64, wherein the bolt c²,
of the shoot c, takes, when the padlock is fastened.
The said end 63, of the staple b, takes within a hole a³, and comes upon a rest a³,
formed with the body ring of the casing a.
The shoot c has a gap and gate c³, stump ct, and inclined lifter lug 05, at its
back.
The underside of the shoot, is gapped at e, for the key to throw the said
shoot to and fro, for locking and unlocking, whilst c is a guide, working upon a
pin a, directed from one of the sides of the locking casing, for determining its
throw.
The common tumbler levers, which are four in number, and marked d, with
gates d², turn upon the pin a³, as a centre, whilst disposed at the back of the
Shoot, of which the tumbler levers come, is a detector lever e, jointed at e²,
provided with a returning spring e, a stump et, and a bent or overhanging
shoulder e, with which latter, the free end f2, of a sear f, in the form of a flat
spring, engages, for holding the detector lever in a position, indicative that a
false key has been applied, or attempted to be used, in the unlocking, or throwing
back of the shoot.
OPERATION.
The locking of the padlock is performed, by placing the true key upon the peg g,
and turning the said key from right to left, when the detector tumbler lever e, is
raised, and its stump e, brought in a line with the gate of the gap c³, of the
shoot and at the same time, the ordinary tumbler levers d, are raised to
positions, which bring the respective gates of the gaps d², in a line with the
shoot stump c, when the further rotation of the key, throws the said shoot into
its locked position, and with the stumps and parts of the mechanism, taking the
positions as represented in figure 1.
Should an untrue or false key, be introduced, and the padlock be attempted to be
unlocked thereby, then the rotation of the said key from left to right, acts upon the
detector tumbler lever, raises it to an abnormal height above the gate of the gap of
the shoot, so as to cause its notch or bent es, to be engaged by the end ", of the sear f,
and by which means, the said detector lever, is held in a raised position, and with its
stump e, taken into a recess c8, of the gap c³, thereby preventing the said shoot, from
being traversed in either direction, by the true or by a false key, until the detector
tumbler lever has been released from the holding sear.
As the padlock cannot be unlocked by the false key, which has placed the detector
in a blocking position, the attempters to pick the lock, would then withdraw the key,
when they found that the same is inoperative.
On the true key being introduced, for the necessary unlocking, the rotation of the
key is inoperative, in its duty, inasmuch as it finds that the same is blocked, and
cannot be opened by ordinary means; thus the non-operation indicates that the lock
has been tampered with.
To place the parts in their respective positions, that the true key may perform its
assigned duties, rotate the said true key in a direction, that it will be turned for
locking. This movement, causes the key, or the bits of it, to engage with the
secondary gap c, of the primary gap e, throw the shoot forwardly a short distance,
when its inclined plane or snug c, comes under the end 2, of the sear f, and lifts it
from the bent e, of the detector tumbler lever e, which now being free, takes its
normal position, as represented in figure 1, by its spring e³.
The parts now being in their respective positions, the true key is turned in the
reverse direction, and operates the shoot, in the ordinary way.
In figure 9 the parts are marked with the same letters of reference, as the preceding
figures, in respect of the padlock, other than in the said figure 9, the latch bolt is
marked h, follower i, lever j, and spring k.

page_text: A single tumbler lever with a stump is only employed in this last named figure,
although two or more ordinary tumbler levers, may be employed in conjunction with
the said stumped lever, if necessary.
I do not confine myself to the means for holding or retaining the detector, on it
being raised above a determinate height, as a swinging arm or catch may be employed,
instead of a sear in the form of a flat spring.
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:-
First A lock or latch, employing in connection with the shoot, or both the shoot
and ordinary tumbler levers of a detector or supplementary tumbler lever, e, es, e³,
which when raised or lifted by a false key, is taken to an abnormal position, and there
held, which thereby blocks the movement of the shoot, until the parts have been
brought again into their proper relative positions by the true key; and which said
parts, are constructed, arranged, operate, and co-operate, substantially as described
and set forth.
Secondly-A double action lock or latch; providing the shoot with a locking and
freeing gap, besides its ordinary stump, and within which said gap, a secondary
stump, carried upon the adjacent face of a supplementary lever, which makes the
double action, takes, so that the stumps of both shoot and supplementary lever, have
at the same time to become lineable with the gates of the ordinary tumblers, and the
gate of the gap of the shoot, substantially as described and set forth.
Thirdly: Holding a detector or supplementary tumbler lever, in an abnormal
raised position, for the purpose of blocking the movement of the shoot, to a false key,
by a sear, catch, or other fastener, engaging with or behind a shoulder of the said
lever, or its equivalent, substantially as set forth.
Fourthly Releasing the shoot from its blocked position (on the reverse movement
being made by the true key) by an incline or pusher off (acting upon the sear or
catch) carried by the shoot upon which the key acts, substantially as set forth.
Fifthly: The improvements in the construction of locks, and detector locks, as
described and set forth in the several figures of the drawings.
Dated this 21st day of March 1890.
CHARLES GROVES.
By Henry Skerrett,
Agent for Applicant.