An Automatic Locking Safety Appliance for Entrances into Hoists and Lifts.
Year: 1888

page_text: Date of Application, 14th May, 1888
Complete Specification Left, 13th Feb., 1889
Complete Specification Accepted, 16th Mar,, 1889
An Automatic Locking Safety Appliance for Entrances into Hoists
and Lifts.
I, ROBERT MIDDLETON, of Sheepscar Foundry, Leeds, in the County of York,
Engineer, do hereby declare the nature of this invention to be as follows:-
Numerous attempts have been made to produce a satisfactory self-acting appliance
such as this for fixing on the various landings. Many of them however interfere
with the legitimate examination of the "well" to ascertain the whereabouts of the
Others are
cage," and also render the control of the latter difficult and dangerous.
costly and cumbrous and defeat their own object by introducing new dangers for
those who have both to work and use the hoist. Others are easily thrown out of
gear and may thus have their beneficial protection evaded by foolhardy persons
wishful to escape control.
The object of my invention is to produce a simple barrier-one to be fitted on
each landing-which shall work automatically and form a safety bar across the
entrance and display a danger signal at all such times as are requisite. This bar or
semaphore arm to be worked by the cage, both in ascending or descending, and
when not being worked to stand locked in its horizontal position of danger, and to
be unlocked only at the proper times and this automatically by the cage. Such unlock-
ing to be beyond the user's control. Further, no movement of the semaphore arm
is to take place except when the cage is in sight in the entrance-this to avoid any-
one being struck by the arm when legitimately looking into the well. All these
from any intermediate landing.
I accomplish my object as follows:-In and at the side of the well, at right angles
to the entrance, 1 arrange a horizontal shaft and I fix thereon a cam which is acted
At the outer end of this same shaft
upon by the cage in passing up and down.
I fix my semaphore arm or barrier which in its mid position (horizontal) extends
across the entrance and stops the way. This arm moving with the cam is caused by
passing cage to move into a vertical position either up or down. It can thus
heathe itself if desired.

page_text: By means of one or more springs, or some equivalent, I cause the semaphore arm
to return to its mid position after a cage has passed. This arm may bear any
suitable danger signal and it will then display it.
Mounted and working on this same shaft is a hollow one, or sleeve, bearing
another cam which is also acted upon by the passing cage. At the outer end of
this sleeve close to the semaphore arm-are mounted double tumblers, similar to
those, say, fitted on the spindle of an ordinary door handle for working in either
direction. These tumblers work inside or in conjunction with a locking-bolt fitted
on the semaphore arm. This locking bolt is provided with a spring which causes it
to catch and lock itself in a suitable detent when the semaphare arm stands in mid
position (danger).
The action brought about by a moving cage is as follows, be the movement up or
down. First the cam on the sleeve is caught and the locking-bolt withdrawn; then,
second, the semaphore arm is swung up or down by the cage acting on the other cam
on the main shaft. The arm is then held in this position and is not released until the
cage has begun to move; but the release is given before the cage is out of sight.
When released the semaphore arm returns to mid position and locks itself; and it
there remains secured until again acted upon by a passing cage. The locking bolt
is preferably arranged so that no-one can tamper with it. The top and bottom
landings may be treated in any ordinary way.
Having now described one arrangement it would not be difficult to devise other
semaphore locking bars as details could be varied at will.
Dated the Tic 1
1000
WM. SNOWDON,
9, Beckett's Bank Chambers,
Leeds, Yorks,
Agent for the Applicant..

page_text: COMPLETE SPECIFICATION.
An Automatic Locking Safety Appliance for Entrances into Hoists
and Lifts.
I, ROBERT MIDDLETON, of Sheepscar Foundry, Leeds, in the County of York,
Engineer, 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 :-
Numerous attempts have been made to produce a satisfactory self-acting appliance
such as this for fixing on the various landings. Many of them however interfere
with the legitimate examination of the "well" to ascertain the whereabouts of the
" cage," and also render the control of the latter diflicult and dangerous. Others are
costly and cumbrous and defeat their own object by introducing new dangers for those
who have both to work and use the hoist. Others are easily thrown out of gear and
may thus have their beneficial protection evaded by fool-hardy persons wishful to
escape control.
The object of my invention is to produce a simple barrier-one to be fitted on each
landing which shall work automatically and forin a safety-bar across the entrance
and display a danger signal at all such times as are requisite. This bar or semaphore
arm to be worked by the cage, both in ascending and descending, and when not being
worked to stand locked in its horizontal position of danger, and to be unlocked only
at the proper times and this automatically by the cage. Such unlocking to be beyond
the user's control. Further, no movement of the semaphore arm is to take place
except when the cage is in sight in the entrance, this to avoid anyone being struck
by the arm when legitimately looking into the "well." All these from any
intermediate landing.
I accomplish my object as follows:-and in order to fully explain my meaning I
have annexed a drawing on which fig. 1, is a Plan view of one way of arranging my
mechanism whilst fig. 2, is a corresponding Sectional Elevation of the Self-locking &
unlocking details.
Figs. 3&4 which I refer to later on represent another arrangement.
The same letters refer to the same parts or their equivalents, as far as possible, in
all the figures.
In and at the side of the "well," at right angles to the entrance, I arrange a
horizontal shaft, A supported in a frame, or frames, A', A', and I fix thereon a cam,
B, which is acted upon by the cage in passing up and down, tappets, or inclined
planes, C and C, being fixed thereon. At the outer end of this same shaft I fix my
semaphore arm or barrier, D, which in its mid position (horizontal) extends across
the entrance to the hoist and stops the way. This arm, D, moving with the cam, is
thus caused by a passing cage to move into a vertical position-either up or down.
It can thus sheathe itself if desired.

page_text: แ
By means of one or more springs, E, or some equivalent, I cause the semaphore
arm to return to its mid position after a cage has passed. This arm may bear any
suitable danger signal and it will then display it-say for instance the word
Danger."
Mounted and working on this same shaft is a hollow one, or sleeve, F, bearing
another cam, G, which is also acted upon by the passing cage. At the outer end of
this sleeve, close to the semaphore arm, are mounted double tumblers, H, H,
similar to those, say, fitted on the spindle of an ordinary door handle for working in
either direction, see fig. 2. These tumblers work inside, or in conjunction with, a locking-
bolt, J, fitted on the semaphore arm. This locking-bolt is provided with a spring,
say as at J, which causes it to catch and lock itself in a suitable detent at K when
the semaphore arm stands in mid position (danger).
The action brought about by a moving cage is as follows, be the movement up or
down. First the cam G on the sleeve F is caught by its tappet,-C¹,-on the
cage, and the locking-bolt, J withdrawn: then, second, the semaphore arm is swung
up or down by another tappet,-C, on the cage acting on the other cam, B, on the
main shaft, A. The arm is then held in this position by the tappet and is not released
until the cage has begun to move, but the release is given before the cage is out of
sight.
a
When released the semaphore arm returns to mid position and locks itself,-the
cam, G, being then released,-and it there remains secured until again acted upon by
passing cage. The locking bolt is arranged so that no one can tamper with it.
This is shown in the Section-fig. 2, where H³, represents a special locking tumbler
which has to be first moved a little way round, by the tappet or inclined plane on
the cage raising or depressing the cam, G,-before either tumbler, H, H, can with-
draw the bolt, J.
A spring or springs must be introduced (say somewhat as at E) to cause the
tumbler, H, to finally return to its central position.
The cam, G, however must not be finally and completely released until the bolt has
shot home into the detent plate K.
The top and bottom landings may be treated in any ordinary way.
Having now described one arrangement it would not be difficult to devise other
semaphore locking bars as details could be varied at will. For instance, Fig. 3, is a
Plan view of another way of embodying my self locking arrangements, and fig. 4, is
a corresponding Sectional Elevation thro' the locking mechanism. A peculiarity of
this arrangement is that the cage, regardless of the direction in which it is travelling,
lifts the arm upwards only and lowers it to the horizontal position when it has passed
oll.
As before, A, is the horizontal shaft supported in a frame A¹ A'; G is a projection
carrying a roller which is actuated by the tappet or inclined plane, C, on the cage.
When G is pressed back the connecting link, H, commences to draw back the
crank B, keyed to the shaft, A, on which is mounted the Semaphore Arm D.
At the first backward movement of G, the link, IL, owing to its slotted hole,-
does not move the crank B, but it takes the opportunity of unlocking the mechanism
by withdrawing the key, H³, out of the hole prepared for its reception.
The backward movement of G, being kept up, the crank, B, is pulled over until
the arm D reaches the vertical line.
This being reached the path of the incline C, reverses and allows G to advance,-
the springs, E, being arranged to accomplish this. The arm D, is then again lowered
into its pocket, K, and then the mechanism locks itself by the tongue H', again
bedding itself into the locking recess arranged in the crank B.
I give preference to this.last arrangement as superior to the other.
It will be understood that either the unlocking cans are arranged out of reach of
a mischievous person's arm, or that the Spring, J', is too strong to be drawn back
by manipulating these cams.
A combination of two or more semaphore arms could be arranged if desired at each
entrance.

page_text: 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) The automatic self locking and unlocking semaphore-barrier, for entrances to
hoists and the like, arranged, constructed, and operated, as described and slown
consisting essentially of mechanism for raising a semaphore barrier after the manner
shown, supplemented by and in combination with a self locking arrangement, all
worked, and mounted on, and from, one Shaft.
Dated thin 191
1000