Improvements in Self Sustaining Pulley Blocks.
Year: 1893

page_text: Date of Application, 29th Nov., 1893
Complete Specification Left, 29th Aug., 1894-Accepted, 3rd Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in Self Sustaining Pulley Blocks.
I, GEORG KIEFFER, of Hebezeugfabrik Köln a. Rh. Germany, Engineer do
hereby declare the nature of this invention to be as follows :-
This my invention relates to improvements in pulley blocks used for lifting or
hoisting weights of any
kind.
The object of my invention is to provide a means by which the pulley blocks
may be self sustaining, and the load or weight may be raised or lowered and left at
any part of the height, and is especially applied to pulley blocks having wormwheel
gearing.
In order to carry out this object I provide a hook as in the usual way, suspended
from which is a frame consisting of two horizontal bearings connected by parallel
side arms, having vertical arms hanging from them which serve as bearings to
carry a worm and sprocket wheel under, for the lifting chain.
I provide a worm pinion and shaft which revolves in the bearings of the frames
aforesaid, the worm pinion actuating the worm wheel and lifting chain. One end
of this shaft is extended through its bearing and has fixed to it a chain or rope
wheel by means of which the weight is raised or lowered. The other end of the
said shaft has a screw thread working in a movable bush or brake collar, having a
large diameter, which fits into and bears against the surface of the bearing. This
screw has only a limited axial stroke and is turned down at its end to a shoulder or
step which bears against a set screw, adjusted from the outside of the bearing.
In lifting the load by means of the chain or rope wheel, the shoulder or step
bears against the set screw, and the screw with limited axial stroke causes the.
brake collar to withdraw from the surface of the bearing, and thus gives free motion
to the gearing, but as soon as the lifting action stops the bush presses against the
surface of the bearing and the load remains self sustained.
In lowering the load the friction is overcome by the chain wheel and the load
descends, but always remains self sustained as soon as the turning stops.
I provide also a modification of this arrangement as an alternative device by
substituing a cap bush or brake collar in place of the brake collar with large
diameter aforesaid and dispensing with the shoulder or step; the surface of the cap
bush itself bearing against the adjustable set screw. The necessary frictional
surface is provided by means of a shoulder or flange on the worm shaft which bears
against the surface of the shaft bearing in the same manner as described with
reference to the first'device.
In place of the screw on the worm axle with limited stroke a worm coupling
may be used or any other device for axial movement with limited stroke. 'The form
of the brake may be conical or any other convenient shape, and the motion of the
brake and step may be caused by means of external friction spring or any other
contrivance.
This device may be adapted for application to one or both sides of the worm on
its axle.
A
ouh day of November 1893
REGINALD W. BARKER,
Applicant's Agent.

page_text: Improvements in Self Sustaining Pulley Blocks.
I, GEORG KIEFFER of Hebezeugfabrik, Köln a. Rb., Germany, 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:-
This my invention relates to improvements in pulley blocks used for lifting or
hoisting weights of any kind.
The object of my invention is to provide a means by which the pulley blocks
may be self sustaining, and the load or weight may be raised or lowered and left at
any part of the height, and is specially applied to pulley blocks having wormwheel
gearing.
In order to carry out this object I provide a hook as in the usual way suspended
from which is a frame consisting of two horizontal bearings, connected by parallel
side arms, having vertical,arms hanging from them, which serve as bearings to
carry a worm, and sprocket. wheel under for the lifting chain..
I provide a worm pinion and shaft which revolves in the bearings of the frames
aforesaid, the worm pinion actuating the wormwheel and lifting chain. One end of
this shaft is extended through its bearing and has fixed to it a chain or rope wheel
by means of which the weight is raised or lowered.**
The other end of the said shaft has a screw thread working in a moveable bush
or brake collar, having a large diameter, which fits into and bears against the
surface of the bearing. This screw is only long enough to give a limited axial
stroke to the brake collar, the limit of the stroke being regulated by a feather and
slot in the brake collar, and is turned down at its end to a shoulder or step, which
bears against a set screw adjusted from the outside of the bearing.
In lifting the load by means of the chain or rope wheel, the shoulder or step
bears against the set screw, and the screw with limited axial stroke. causes the
brake collar to withdraw from the surface of the bearing, and thus. gives free
motion to the gearing but as soon as the lifting action stops, the bush presses
against the surface of the bearing, and the load remains selfsustained.
In lowering the load, the friction is overcome by the chain wheel and the load
descends, but always remains selfsustained as soon as the turning stops.
I provide also a modification of this arrangement as an alternative device, by
substituting a cap bush or brake collar in place of the brake collar with large
diameter aforesaid, and dispensing with the shoulder or step, the surface of the cap
bush itself bearing against the adjustable set screw. The necessary frictional
surface is provided by means of a shoulder or flange on the wormshaft which bears
against the surface of the shaft bearing in the same manner as described with
reference to the first device.
In place of the screw on the worm axle with limited stroke aforesaid, a worm
coupling may be used or any other device for axial movement with limited stroke.
The form of the brake may be conical or any other convenient shape, and the
motion of the brake and step may be caused by means of external friction, spring,,
or any other contrivance.
These devices may be adapted for application to one or both sides of the worm
on its axle.
In order that my invention may be clearly understood, I will describe the same
with reference to the accompanying drawings in which
Fig. 1 represents a sectional elevational of a pulley block, having a screw thread
working in a moveable bush or brake collar with large diameter, which fits into and
bears against the surface of the bearing.
1

page_text: Fig. 2. is an enlarged section of the friction brake, and
Fig. 3 is a cross view of the moveable bush, shewing the provision for limiting
the axial stroke.
In these views A is the worm shaft and worm for actuating the worm wheel B,.
which raises or lowers the load. C is the bearing frame arranged so as to receive
the moveable bush or brake collar D. E is the step or shoulder, turned down from
the wormshaft A and screw thread G, and which bears against the adjustable set.
screw F. In raising the load, the end of the wormshaft at E thrusts against the
adjustable screw F and the moveable bush or brake collar D travelling along the
thread G, causes it to be withdrawn from the surface S of the bearing. As soon
however as the lifting action stops, the load by the thread G causes the brake ring
or collar D to press against the surface S of the frame C, drawing back the end of
the wormshaft from its bearing against the set screw F and the load remains
sustained in position. In lowering the load, the wormshaft A is turned in an
opposite direction, but the brake ring or collar D remains in action on the surface S
of the frame bearing C. H is a feather on the screw G, which screw has part of its
threads cut away at J, by which a limited axial stroke is given to the collar D,
just sufficient to release it from the surface S when required.
Thus the load can be easily raised or lowered by turning the wormshaft A, but
is self sustained as soon as turning stops.
Fig. 4 shews a modification of this arrangement beforementioned having the
alternative device of a cap bush and friction shoulder or flange in place of the
aforesaid brake collar or ring. Fig. 5 is an enlarged sectional detail of the same,
and Fig. 6 is a cross section.
In these views A is the worm shaft, B the wormwheel, C the bearing frame
receiving the cap bush K. G is the screw thread working in the cap bush K
which thrusts against the adjustable set screw F. In this arrangement the worm-
shaft A has a friction flange L between the worm and the screw thread G, the
surface of which bears against the bearing frame in the same manner as described
with reference to Figs. 1, 2 & 3. The axial stroke of the cap bush is limited by a
feather and slot in the same manner as shewn in Fig. 3.
Fig. 7 shews a sectional view of a worm coupling, the worm shape edges of the
coupling being shewn at M, and the frictional surface being obtained by the flange
on the worm shaft at N.
Figs. 8 and 9 shew modifications of the principles of my invention applied to
various forms of worm and worm wheel gearing used for hoisting purposes.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. Self sustaining gear for pulley blocks, substantially as herein set forth and
described and illustrated by the accompanying drawings.
2. In pulley blocks having worm gearing or similar appliance for lifting or
hoisting weights of any kind the combination of self sustaining gear substantially as
herein set forth and described and illustrated by the accompanying drawings.
Dated this Twenty-ninth day of August 1894.
REGINALD W. BARKER,
Applicant's Agent.