Improvements in and connected with the Sheaves or Pulleys of Elevators or Lifts.
Year: 1894

page_text: Date of Application, 3rd July, 1891-Accepted, 4th Aug.,
1891
COMPLETE
SPECIFICATION.
Improvements in and connected with the Sheaves or Pulleys of
Elevators or Lifts.
A communication from abroad by OTIS BROTHERS & COMPANY, of 38, Park Row,
New York, in the United States of America, Manufacturers.
We OTIS ELEVATOR COMPANY LIMITED of 4 Queen Victoria Street in the
City of London 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 the sheaves that are used for guiding the deflected cables
of elevator apparatus, and consists of certain means fully set forth hereinafter,
whereby the sheave may be brought into proper relation with the cable and the
winding drum at the end of each movement of the sheave.
In the accompanying drawings:
Figure 1 is a front elevation of sufficient of the winding devices of an elevator
to illustrate the invention.
Figure 2 is a side view of the guide sheave.
Figure 3 is a transverse sectional view of the guide sheave.
Figure is a side view of the guide sheave showing another means of adjusting
the stops thereon.
Figure 5 is a vertical sectional illustration of the parts illustrated in Figure 1,
but showing a two-part sheave.
Figure 6 is a transverse sectional view of the sheave shown in Figure 5.
Figure 7 illustrates a modification.
The winding drum C is connected with an operating engine of any suitable
construction, either a steam engine, belt engine, electrical engine, or otherwise, and
has spiral grooves for the reception of one, two or more parallel cables, which pass
from the drum to the top of the well, and are connected to the cage or platform.
Where the cable or cables d (two cables being shown) have to be deflected, they
pass around a guide sheave A, the hub 7 of which constitutes practically a nut that
turns upon a threaded shaft B supported stationary in hangers 2, 2, suspended from
a roof or ceiling, or connected to a wall, or otherwise supported.
As the cables move in contact with the sheave they rotate the latter and the
sheave travels on the threads of the screw shaft, thereby avoiding the wearing of
the cables that results when the latter are depended upon to drag the sheave
laterally on the plain shaft.
The pitch of the thread of the shaft B is such that the sheave A will move as
fast as the lateral displacement of the cables, so that the sheave will be practically
in the vertical plane of the cables at all times, so that there can be no possible
tendency of the winding sheave to lag behind and allow the portion of the cable
between the sheave and the winding drum to assume an angle that would throw the
cables off the sheave.
for
In order to preserve this alignment, however, and compensate any inequalities
in action, means are provided whereby there is an adjustment of the sheave in
respect to the winding drum and cables at the end of each stroke. Such means
consist of contact pieces E, E, upon the sheave, and contact pieces D, D, supported
by the hangers or brackets 2, or any other stationary part of the apparatus, and so
arranged that one of the contacts upon the sheave will meet one of the contacts
upon the frame when the sheave reaches the proper limit of its movement in either
direction, and means are provided whereby to permit a limited movement of the cable
if necessary after the sheave has been brought to rest by the meeting of the contacts.

page_text: Thus assuming that the sheave A has moved to the right until the contact E on
the sheave at the right has met the contact D upon the frame at the right, the
sheave will then be arrested in movement, and if the drum continues its movement
thereafter, the cables will slip over the sheave until the movement of the drum is
arrested. When therefore the movement of the drum is reversed, the sheave will
start back in its proper position in respect to the drum and the cables, towards the
left hand end of the hanger, where a like operation will ensue, the sheave thereafter
starting on its return movement towards the right in proper relative position to the
cables and the drum.
As in many instances the height of the well is such that the cable need not be
completely unwound from the drum in order to secure the proper travel of the cage,
the contacts may be adjustable so as to meet when the sheave A is at any desired
point upon the screw B. For instance, each stop D may consist of a threaded
rod 8 passing through the hanger 2, and provided with clamping nuts 9, 9, by
which the stop may be set to and secured in any desired position. As it is
necessary also to set the stops E in different positions, each of the arms 6 of the
sheave A may have a threaded opening to receive the threaded stem of the
stop E consisting practically of a screw bolt, or the stop may be a projection E
upon one of two clamping plates 5 arranged on opposite sides of the spokes 6 and
clamped together to the said spokes in any suitable position by means of bolts and
nuts 10, 10.
Where it is desired to avoid the running of the cables over the sheave A after the
latter has come to rest, and the friction and wear that would result therefrom,
means may be employed for permitting the movement of the rim of the sheave with
the cables without moving the hub 7 constituting the nut.
Thus, as shown in Figures 5 and 6, the rim of the wheel has a central opening
and is clamped between two discs 12, 12, which constitute the hub or nut of the
wheel, the clamping being effected by means of screw holts 14 which may be
adjusted to secure any desired frictional adhesion of the hub and the rim of the
wheel. Arms E projecting from the discs 12, 12, constitute the stops and when
either arm strikes a stop D, the travel of the sheave upon the screw shaft B is
prevented but the rim of the sheave may move to a certain extent with the cables d
so that there is no frictional travel of the cables upon the rim.
In the construction shown in Figure 7, the shaft B is splined at one end to slide
in the hanger 2, while the other end is threaded and passes through a nut 20
turning in bearings in the hanger 2, the sheave or sheaves A turning between
collars secured to the shaft.
The nut carries a sprocket wheel 21 to which a sprocket chain 22 passes to a
sprocket wheel 23 on the shaft of the drum C so that the turning of the dram
positively drives the nut 20 and slides the shaft to the exact extent required.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed as communicated to us by
our foreign correspondents we declare that what we claim is
1. The combination of a winding drum, screw shaft, sheave for the cable passing
from the drum, and means substantially as described for imparting the desired
lateral movements to the sheave
2. The combination with the drum and cable of an elevator apparatus, of a
stationary screw shaft, a pulley having a threaded hub travelling thereon, contacts
on the pulley and on the stationary frame, and means for permitting a limited
movement of the cable after one of the contacts has been brought to bear against
the other, substantially as set forth.
3. The combination with the drum, cable and guide sheave of an elevator, of
contacts upon the frame of the apparatus, and contacts upon the sheave arranged
to strike and arrest the movement of the sheave when it reaches the limit of its
travel in either direction.
4. The combination with the drum and cable of an elevator apparatus, of a

page_text: stationary screw shaft, a sheave thereon, stops upon the sheave, and stops
longitudinally adjustable upon the frame of the apparatus, substantially as
set forth.
5. The combination with the drum, cable, sheave, and stationary screw shaft, of
stops upon the frame of the apparatus, and stops carried upon the sheave and
adjustable to different positions upon the sheave, substantially as and for the
purpose set forth.
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1
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1004
PHILIP M. JUSTICE,
Chartered Patent Agent, 55 & 56, Chancery Lane, London,
For the Applicants.