IMPROVEMENTS IN SAFETY-LIFTS
Year: 1884

page_text: "
I, MORITZ MARTIN, of Bitterfeld, Prussia, manufacturer, do hereby declare
the nature of said invention for "IMPROVEMENTS IN SAFETY-LIFTS to be as
follows
My invention relates to lifts for raising and lowering goods in warehouses,
factories, &c., and the floor-openings whereof are guarded by doors, and it consists
in a device for preventing the lift from being moved away from a floor so long as
the doors of the same floor are not completely closed. Besides, the invention com-
prises mechanism serving to keep the doors of any floor locked except when the
lift is on a level with the floor.
For the purpose of preventing the lift from being put in motion while the doors,
guarding the floor opening of the lift, are open, the rod (or rope) leading to the
starting-lever of the winding-machinery and brake, has a sliding-piece connected to
it, provided with a notch, and to the door is fixed a sector, which, when the door is
open, engages with the said notch, so that under these conditions no pull or thrust
can be transmitted by the road to the said machinery; whereas when the door is
closed the sector leaves the notch of the sliding-piece, the rod being then free to be
operated for releasing the brake, or for putting in addition thereto the winding-
machine into gear.
The door-locking mechanism consists in a spring-actuated bolt, placed sideward
of the path of the lift and operating a locking-piece adapted to engage with, and
lock the door. Moreover there is on the lift a tappet arranged to draw back the
bolt, and thereby to unlock the door when the platform of the lift arrives in the
floor-opening guarded by the door. When the said bolt is on the same side of
the lift as the hinges of the door, it may be caused to engage with a notched arm
on the door; no separate locking-piece being in this case required.
When doors with two leaves are employed, the leaves are fixed to axles connected
together by means of two pairs of bevel wheels and an intermediate shaft, so that
both doors will be dependent upon each other in their motion,

page_text: COMPLETE SPECIFICATION.
I, MORITZ MARTIN, of Bitterfeld; Prussia; manufacturer; do hereby declare the
nature of my invention for "IMPROVEMENTS IN SAFETY-LIFTS" 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 lifts for raising and, lowering, goods in warehouses,
factories, &c, the floor openings whereof are guarded by doors; and it consists in a
device for preventing the lift from being moved away from a floor so long as the
doors of the same floor are not completely closed: Besides, the invention comprises
mechanism serving to keep the doors of any floor locked except when the lift is on
a level with the floor.
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The invention is represented on the annexed sheet, of drawings. Fig. 1 shows in
a vertical sectional side view a lift provided with my, invention. Fig. 2 is a
sectional plan thereof. Fig. 3 is a vertical section and Fig. 4 a sectional plan of
the device for controlling, the starting of the lift, the door being supposed to be
closed. Fig. 5 is a plan showing the position of the parts when the door is open.
Fig. 6 shows a modified arrangement of a portion of the device. Fig. 7 represents
a modification of the door-locking mechanism. Figs. 8 and 9 aro respectively
& front elevation and a sectional plan of a lift having a door with two leaves.
L
For the purpose of preventing the lift from being put in motion while the doors,
guarding the floor opening of the lift, are open, the fod (or, rope) leading to the
starting-lever of the winding-machinery and brake, has a sliding-piece connected to
it, provided with a transverse notch, and to the door is fixed a sector, which, when
the door is open, engages with the said notch, so that under these conditions no pull
or thrust can be transmitted by the rod to the said machinery; whereas when the
door is closed, the sector leaves the notch of the sliding-piece, the rod being; then
free to be operated for releasing the brake, or for putting in addition thereto the
winding-machine into gear.
...
F
In Figs. 1 and 2, f is the lift, a the door, and the rod (or rope) leading to the
starting-lever of the winding-machinery and brake. The latter parts are not shown
in the drawing, as they do not constitute any part of the invention, and as they
may be of any known construction. To the said rod c is connected the sliding-
piece h (see also Figs. 3, 4 and 5) represented in the drawing as being round
in section, but which may be of any other convenient sectional, shape. This piece
is vertically movable in the guide g, but so as to be prevented from rotating, for
which purpose it may be provided with a groove into which projects a screw
To the door d is fixed the sector a extending through a horizontal slit of the
guide g into a notch q cut into the piece. The sector has a notch m corresponding
to the sectional form of the piece h, and which registers with the latter when the
door is closed. The parts being thus arranged and the door closed, as in Figs. 1
to 4; the piece is free to pass through the notch m; the rod c may consequently
be moved to operate the starting-lever of the winding-machine, and thus to put the
lift in motion. But, when the door is opened, however little, the notch m does not
register any more with h, and no pull or thrust can be exercised by means of the
rod c. Fig. 5 shows the position of the sector a when the door is fully open.

page_text: In the modification represented by Fig. 6, the sector is provided within the
notch m with a tooth k, the piece h having a groove to correspond therewith. This
tooth may be tapered towards the top and the bottom, so that in case the door d is
not fully closed, the motion imparted to the rod c will cause the sides of the said
groove to act against the inclined surfaces of the tooth and thereby to completely
close the door.
The door-locking mechanism comprises a bolt, actuated by a spring, so as to keep
another bolt or catch in engagement with the door, and which a tappet on the lift
draws back when the platform of the lift arrives in the opening guarded by the
door. In Fig. 2, s is the main bolt and n the spring which pushes it towards the
door d. At the end towards the back of the lift, the bolt is bent at a right angle,
and against this portion of the same, which is preferably provided with a roller o,
acts the tappet or cam l, adapted to push the bolt backward against the pressure of
the spring n. These parts are, however, not new, as they have been described in
the specification of my United States patent No. 27 1884. But with the said bolt
another bolt or locking-piece r is combined, actuated by a spring to engage with a
mortice in the door, while at the end of the bolts there is an inclined surface which
acts against a shoulder on the piece r to withdraw it from the mortice when the
bolt 8 is drawn back by the tappet . The door will thus be free to be opened
when the lift is in the position shown in the drawing, while it is kept locked so
long as the lift is above or below this position.
According to Fig. 7 the locking-piece r consists in a bell-crank lever, one arm
of which forms the catch engaging with the door, while the other arm is in
connection with the bolt 8.
The figures 8 and 9 show an arrangement in which the floor-opening of the lift
is guarded by a door with two leaves, the axles p whereof are fixed to the leaves
and so connected together by the bevel-wheels e and the shaft b that the motion of
either leaf is dependent upon the motion of the other one. For ensuring the
complete closing of both door-leaves before the lift can be raised or lowered, it is
therefore but necessary to provide one of them with the device for locking the
starting-rod c, and one with the door-locking mechanism, as is shown by the
drawing. The latter mechanisın, in this case, consists in the bolt 8 alone, engaging
with a notched piece t fixed to one of the leaves and adapted to prevent the leaf
from being moved when the bolt is in the notch.
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 lift, the floor-openings whereof are guarded by doors & turning on axles,
the combination with a door d and the starting-rod or rope c, of the sliding-piece h
having a notch q, and of the sector a having the notch m, substantially as and for
the purpose described.
2, The combination with the door d, provided with sector a, arranged to engage
with the sliding-piece h, of a locking-piece r, adapted to engage with the door by
the action of a spring, and to be withdrawn from the door by the tappet and the
bolt 8, substantially as and for the purpose specified.