Improvements in Hoisting Machinery.
Year: 1889

page_text: Date of Application, 3rd Apr., 1889
Complete Specification Left, 3rd Jan., 1890-Accepted. 3rd Apr., 1890
PROVISIONAL SPECIFICATION
Improvements in Hoisting Machinery.
PICKERINGS Limited, and JOSEPH Thompson PickerinG, Managing Director of the
said Company, of Globe Works, Stockton on Tees, in the County of Durham
Engineers, and EDWARD WILLIAM SANT, and ALFRED RALPH DAVIES, Employés and
Shareholders in the said Company of Pickerings Limited, do hereby declare the nature
of this invention to be as follows:-
This invention relates to improvements in the starting and stopping or controlling
arrangements in connection with machines used for elevators or lifts, hoists, & similar
appliances. An automatic stopping action which is intermittent, is obtained by
means of differential gear, working in connection with the ordinary starting arrange-
ment, but leaving it free for independent use. Suitable powers of adjustment are
provided so that by the use of our invention a hoisting machine can be made to
arrest itself automatically either at the extreme ends or at any intermediate point in
its travel.
The differential gear works in conjunction with an improved arrangement of belt
shifter, which, after removing the belts, causes them to remain immovable, although
the machine may continue to revolve until its momentum is arrested. The extra
motion due to the momentum is taken up without any possibility of imparting further
travel to the belts and so reversing the machine.
The arrangements described are therefore for the purpose of obtaining more perfect
control in starting or stopping hoisting machinery, for preventing excess in winding
or unwinding, and for ensuring certainty of action in stopping the load at any fixed
points in the length of travel.
The combination, of differential gear, with the improved belt shifter. goes towards
completing our improvements which, while admitting of modifications, may be
described in connection with a hoisting machine as follows. "An ordinary starting
barrel, to which the usual controlling ropes or chains can be attached, is carried
loosely by one of the shafts of the hoisting machine, preferably the hoisting shaft."
Within the barrel differential gear is enclosed of the kind used in pulley blocks,
described in the patent granted to Jonathan Pickering, 3rd April 1867 No. 990,
driven by the shaft and revolving independently of the starting barrel. An eccentric
is fixed to the shaft to give motion to a driving pinion which gears into two internal
wheels of equal diameter but differing in the number of their teeth. One of the
internal wheels is fixed to the barrel the other is free to revolve on the shaft. A
projecting arm attached to the moving wheel travels slowly round the outer edge
of the barrel, which barrel has a circular groove fitted with sliding stops capable of
being adjusted and fixed at any point in the circle. When the projecting arm meets
one of the stops, it carries the barrel with it, compelling the barrel to revolve
together with the shaft and differential gear. The result is that motion is imparted
to the special arrangement for shifting the belts, which we will now describe. The
starting barrel is connected by an endless chain and chain wheels, or by any other
suitable arrangement, to a wheel or segment of a wheel of suitable diameter, on the
periphery of which are one or more helical grooves or scrolls forming a spiral or
spirals or its or their equivalent. These grooves receive one or more projections
placed on the belt shifting bar. The effect of which is that the belt shifting bar
has a longitudinal motion whenever the helical or spiral wheel revolves. The helical
grooves above described are at certain points formed so as to merge into straight
lines, at right angles with the axis on which the wheel revolves, so that when the
projections on the fork bar mesh with the straight lines no further longitudinal
motion is transmitted to the bar.

page_text: These improvements are more especially applicable to be worked in connection
with the patent granted to Jonathan and Joseph Thompson Pickering 25th January
1883 No. 415, and are mainly to be used on power machines for lifts, or other hoisting
machinery.
"
1 1000
JOSEPH THOMPSON PICKERING.
EDWARD WILLIAM SANT.
ALFRED RALPH DAVIES.
For Pickerings, Limited,
Thos. R. Rowntree, Secretary.
COMPLETE SPECIFICATION.
Improvements in Hoisting Machinery.
PICKERINGS Limited and JOSEPH THOMPSON PICKERING, Managing Director of
the said Company of Globe Works Stockton on Tees in the County of Durham
Engineers and EDWARD WILLIAM SANT and ALFRED RALPH DAVIES Employés and
Shareholders in the said Company of Pickerings Limited, do hereby declare the
nature of our 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 relates to improvements in the starting and stopping or controlling
arrangements, in connection with machines used for elevators or lifts, hoists, and
similar appliances. An automatic stopping action, which is intermittent, is obtained,
by means of differential gear, working in connection with the ordinary starting
arrangement, but leaving it free for independent use. Suitable powers of adjustment
are provided, so that, by the use of our invention, a hoisting machine can be made
to arrest itself automatically, either at the extreme ends, or at any intermediate point
in its travel.
The differential gear works in conjunction with an improved arrangement of belt
shifter, which, after removing the belts, causes them to remain immovable, although
the machine may continue to revolve until its momentum is arrested. The extra
motion due to the momentum, is taken up, without any possibility of imparting further
travel to the belts, and so reversing the machine.
The arrangements described are therefore for the purpose of obtaining more
perfect control in starting or stopping hoisting machinery; for preventing excess
in winding or unwinding; and for ensuring certainty of action in stopping the load,
any fixed points in the length of travel.
at
And in order that our said invention may be particularly described and ascertained,
reference is hereby made to the accompanying drawings, in which similar letters of
reference indicate corresponding parts.
Fig. 1. is a plan of a machine driven by belts for working a lift. Fig. 2. is a
plan shewing the development of the grooves on the periphery of the wheel O. Fig. 3.
is an elevation of the controlling barrel A. Fig. 4. is an elevation of the wheel F,
and Fig. 5 is an elevation of the eccentric C and the driving pinion D.
A is the controlling barrel, working free on the winding shaft B, upon which the
eccentric C is keyed. D is a pinion carried by the eccentric C and gearing into
the internal wheels E and F, which are equal in diameter but differ in the number
of their teeth. The wheel E is part of the barrel A, but the wheel F, which is
provided with an arm or striker G, works independently and loosely on the end of
the shaft B. HH' are stops carried by the pins J J which slide in the circular
groove K. L is a chain wheel attached to the barrel A, and M is a chain wheel
forming part of the wheel O. N is an endless chain connecting the chain wheels L
and M. P P and V are grooves on the face or periphery of the wheel O, which is
carried by the stud R. S S₁ are rollers projecting from and attached to the belt
shifting bar T.
The action of the combined parts is as follows: The shaft B drives the eccentric C

page_text: causing the pinion D to revolve within the internal wheels E and F. The internal
wheel E remains at rest together with the barrel A, which is held by the starting
chain or rope. The differential arrangement of teeth causes the internal wheel F to
receive motion from the working pinion; and it revolves slowly until the arm or
striker G is brought into contact with one of the stops H H. The result is that the
barrel A and chain wheel L are forced to revolve at the same rate of speed, and in
the same direction, as the shaft B. The stops H H are adjustable, and can be moved
and fixed to any point on the circular groove K. The chain wheel L, in revolving,
drives, through the endless chain N, the chain wheel M, which is connected to O, so
that any motion given to the barrel A, is at once imparted to the wheel O. The
grooves P P on the wheel mesh with the projecting rollers S S¹ on the shifting
bar T. The effect of which is that the bar T is moved horizontally whenever the
wheel revolves. But when the bar T has travelled the required distance, one of
the rollers S¹ enters the straight groove V, which allows the wheel O to continue.
revolving, while the bar T remains at rest, during which time the momentum of the
machinery is arrested.
Having now particularly described and ascertained the nature of our said invention,
and in what manner the same is to be performed, we would remark that we do not
limit ourselves to the precise details herein given, as they may be varied and modified
without departing from the main feature of our invention. We would also state
that we make no claim to well known parts of the mechanism which are shown to
illustrate the mode applied to our improvements; we declare that what we
claim is
1. In the construction of hoisting apparatus; the combination of differential gear,
the grooved wheel O, the shifting bar T fitted with rollers S¹, operated by the
grooved wheel O, substantially as and for the purposes hereinbefore described and
illustrated by the drawings.
2. The combination and arrangement of the several and respective parts together
forming our improvements in apparatus for starting and stopping hoisting machinery
substantially as and for the purposes hereinbefore described and illustrated by the
drawings.