Improvements in Indicator Locks or Latches.
Year: 1895

page_text: Date of Application, 18th Feb., 1895-Accepted, 23rd Mar.,
1895
COMPLETE SPECIFICATION.
Improvements in Indicator Locks or Latches.
I, JOHN MANN LOCKERBIE of Exeter Street Birmingham in the County of
Warwick, Merchant, do hereby declare the nature of the said 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 has for its object improvements in indicator or tell tale locks or.
latches for use in such places as lavatories, water closets &c. where a charge is
made for the use of same, whereby great simplicity of the working parts forming
such lock or latch is obtained and consequently the cost is small. At the same time
it is almost impossible for it to get out of order and if such was the case it could
be repaired in a very short time by any ordinary mechanic.
In order that my invention may be properly understood and readily carried into
effect I will proceed aided by the accompanying drawings fully to describe the
same, in all the figures like parts are indicated by similar letters of reference.
Figure 1 is an elevation with the back plate removed of a lock or latch constructed
according to my invention.
Figure 2 is a front view of the same.
Figure 3 is a similar view to Figure 1, after the key has been inserted and the
bolt withdrawn from its staple.
Figure 4 is a similar view showing the position of parts after the knob has been
turned-and-
Figure 5 is an edge view of the parts for actuating the index or tell tale.
According to my invention I construct the housing or easing, a, in the usual
manner. The bolt, b, is formed H shaped the narrow or central part, b', of which
works between guides or stops a' and is kept in its proper position by a spring, c,
the end, c', of which bears against the stop, a', and the other end, c³, bearing behind
the head of the bolt.
The bolt, b, is controlled on the outside of the door by means of a key operating
the sliding piece, d, one end of such sliding piece has formed thereon an enlarge
ment or projection, d', which engages with the tail end, 2, of the bolt, b, and
between that and the stop, a'.
The sliding bolt or piece, d, is formed with a horizontal slot or guide, d³, at
its rear end which works on a stud or pin, e, fixed to the casing, a. The front
end of this sliding piece or bolt, d, has a radial slot, d³, which works on a pin or
stud, f. This sliding piece, d, is provided with the stop, d, and the levers or
tumblers, g*.
On the key being inserted and turned it causes the projection, d', at one end of
the said sliding piece, d, to engage with the tail end, 6, of the holt, b, and on the
key being further turned the sliding piece, d, will travel horizontally by virtue of
the slot, d, sliding over the stud or pin, e, and radially by virtue of the slot, d³,
working over the stud or pin, f. It will thus be seen that the bolt, b, will be
withdrawn from its staple.
The upper edge of the sliding piece on bolt, d, has a lump, d, formed thereon
which engages during the horizontal and radial travel of said sliding piece with
one arm or projection, gl, formed on the cam, g. The cam, g, and the gear wheel, i,
are fixed to or formed in one with the sleeve, h, which rotates in the bracket, i".
Passing through the sleeve, h, is a square shaped spindle, j, which is connected up
by a pinion to a chain of wheels forming the tell tale or index, k.

page_text: It will thus be seen on the lump, d, on the sliding piece, d, striking the projection
or arm, g', on the cam, g, that the cam, g, and the gear wheel i will make a partial
revolution thus causing the spindle, j, to operate by means of its pinion the chain
of wheels in the tell tale or index k and to register such partial revolution on the
unit dial of such index.
The gear wheel i on the cam spindle or sleeve engages with a loose gear
wheel provided also with a cam m having arms or projections m¹ similar to the
cam g and is arranged so as to pass under such cam 9 as clearly shown in
Figure 5.
The bolt b is controlled on the inside of the door by means of the knob n which
operates by virtue of the cross piece or follower n' on the knob spindle n³, the
sliding piece or bolt p which moves both horizontally and radially similar to the
sliding piece d before referred to.
The said sliding piece p has a projection or enlargement p' which engages in
the tail end of the bolt b and on such sliding piece p being operated by means of
the knob n will withdraw the bolt 6 from its staple. The rear underside of this
sliding piece is slotted to allow of its easily travelling over the feather a³ formed
in the case a thus ensuring an even and steady movement of the sliding piece p, a
spring bears against the rear end of the sliding piece p to keep it in its proper
working position.
A lump or projection is formed on the lower edge of the sliding piece p which
engages with the projections or arms m² of the cam m. The underside of this
Jump p is cut away to allow of it passing freely over the gear wheel 7.
The operation of the lock or latch is as follows:-
On the key being inserted and the bolt withdrawn from its staple the lump a³
will strike against the arm, or projection g' on the cam 9 and cause the index finger
to rotate a half space on the unit dial. At the same time it will cause the gear
wheel and the cam g to rotate and gearing into the loose wheel it will cause the
cam m also to rotate and to leave one of its arms or projections m³ in such a
position that on the sliding piece p travelling in its horizontal and radial path will
strike against such cam projection m¹ and cause a further partial revolution of the
gear wheel i and consequently the spindle ; and its pinion thus communicating
motion again to the chain of wheels and causing another half space to be registered
on the unit dial.
Thus showing on the dial that the door had been opened by the key from the
outside and again opened and closed by means of the knob from the inside.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is.
1. The general arrangement and combination of parts constituting an indicator
or tell tale lock or latch substantially as herein described and shown in the
accompanying drawings.
2. In indicator or tell tale locks or latches the combination therewith of the
sliding pieces or bolts such as d and p having lumps or projections d³ and p² for
engaging with the arms g¹ and m² and thus causing a partial revolution of the
index finger on the dial substantially as described and shown.
3. In indicator or tell tale locks or latches the arrangement and combination of
parts for operating the cams 9 and m and thereby communicating motion to the
spindle and causing the index finger to register such revolution on the dial
substantially as herein described and shown in the accompanying drawings.
Dated this 18th day of February 1895.
JOHN MANN LOCKERBIE.