Improvements in Hoisting Mechanism and Devices for Checking Backward Rotation.
Year: 1889

page_text: Date of Application, 16th Oct., 1889
Complete Specification Left, 16th July, 1890-Accepted, 23rd Aug., 1890
Improvements in Hoisting Mechanism and Devices for Checking
Backward Rotation.
A communication from abroad by THOMAS ALDRIDGE WESTON, of Stamford
Connecticut, United States of America, Engineer.
I, JOHN CLAYTON MEWBURN of 55 and 56 Chancery Lane in the County of
Middlesex Fellow of the Institute of Patent Agents do hereby declare the nature of
this invention to be as follows:-
This invention relates primarily to portable lifts or geared pulley blocks; also to
fixed lifts.
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To construct a geared pulley block according to this invention I employ two disc
formed side frames united by studs and a cross-head, the latter provided with the
usual suspension hook. The said disc frames are spaced apart to admit between them
centrally a toothed lifting sheave for engagement with the links of the load chain.
The said lifting sheave is integral with a hollow main shaft supported at its ends by
bearings in the two side frames, and at one end the said shaft projects beyond its
bearing in the frame for attachment to a rotating cast frame wherein are placed the
planet pinions of a train of gearing of the kind well known as sun and planet
gearing. The said planet pinions are each double, or of two diameters, and at their
larger diameter they all engage with a central or "sun" pinion made integral with a
driving shaft having its main bearing central through the length of the above named
hollow main shaft. The smaller diameter of each planet pinion engages with an
internally toothed annular wheel rim surrounding them and cast upon or attached
to the adjacent side frame. The short cylinder thus formed by the annular wheel
rim and the side frame is closed at its outer end by a cover which has a central boss
forming an end bearing or out-bearing to the central driving shaft. All the spur
gearing is thus enclosed from dirt or injury on one side of the machine and external
to its side frame. The other side frame contains an improved ratchet roller check
device for retaining the load as hereinafter described; and upon the same side frame
exterior, close thereto, is the driving pulley or sprocket wheel and usual endless hand
chain.
I thus obtain a symmetrical or balanced three-fold grouping of the enumerated
parts upon one common axial or shaft centre; viz.-On one side of the machine
external to the main frame I place the improved driving, braking and checking gear;
on the other side, also external to the main frame I enclose all the spur gearing; and
centrally within the main frame I place the lifting sheave and its load chain in the
same plane with the suspension hook.
The improved checking and braking device consists of an annular recess in the
outer side of the adjacent side frame within which recess is a casting or roller ratchet
case provided at. its periphery with a series of excentric or cam shaped faces to each of
which faces is applied a short cylindrical roller, the said rollers being confined to their
places by the outer convex wall of the said annular recess in the frame. The said
roller ratchet case is free to revolve one way only along with its ratchet rollers, and it
has horns or lugs projecting outwardly to engage loosely with the rims of the frictional
discs such as are referred to in the Specification of Patent No. 263 of 1863. The said
friction discs are engaged in part with the central driving shaft by the intervention of
a brake casting secured to the said shaft. The said brake casting also carries, by a
screw thread on its central boss, the driving pulley or sprocket wheel with its endless
hand chain whereby the machine is operated.
The aforesaid roller ratchet checking device, being self-contained within one of the
side frames as to all its strains, having only a loose driving engagement with the

page_text: parts checked from backward rotation, is obviously applicable to other machines any
parts of which need to be checked in like manner against backward rotation.
The improved portable or suspended lift I have described is obviously capable of use
when its supporting frame is a fixed one.
COMPLETE SPECIFICATION.
Improvements in Hoisting Mechanism and Devices for Checking
Backward Rotation.
A communication from abroad by THOMAS ALDRIDGE WESTON,. of Stamford
Connecticut, United States of America, Engineer.
I, JOHN CLAYTON MEWBURN of 55 and 56 Chancery Lane in the County of
Middlesex, Fellow of the Institute of Patent Agents, 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 primarily to portable lifts or geared pulley blocks; also to
fixed lifts.
To construct a geared pulley block according to this invention, I employ two disc
formed side fraines, united by studs and a crosshead, the latter provided with the
usual suspension hook. The said disc frames are spaced apart to admit between them
centrally, a toothed lifting sheave for engagement with the links of the load chain.
The said lifting sheave is integral with a hollow main shaft supported at its ends by
bearings in the two side frames;, and at one end the said shaft projects beyond its
bearing in the frame, for attachment to a rotating cast frame wherein are placed the
planet pinions of a train of gearing of the kind well known as "sun and planet"
gearing. The said planet pinions are each double, or of two diameters; and at their
larger diameter they all engage with a central or "sun" pinion made integral with a
driving shaft having its main bearing central through the length of the above named
hollow main shaft. The smaller diameter of each planet pinion engages with an
internally toothed annular wheel rim surrounding them and cast upon or attached
to the adjacent side frame. The short cylinder thus formed by the annular wheel
rim and the side frame, is closed at its outer end by a cover which has a central boss
forming an end bearing or out-bearing to the central driving shaft.
All the spur
gearing is thus enclosed from dirt or injury on one side of the machine and external
to its side frame. The other side frame contains an improved ratchet roller check
device for retaining the load as hereinafter described; and upon the same side fraine
exterior, close thereto, is the driving pulley or sprocket wheel and usual endless band
chain..
I thus obtain a symmetrical or balanced three-fold grouping of the enumerated
parts upon one common axial or shaft centre, viz.: On one side of the machine external
to the main frame, I place the improved driving, braking and checking gear; on the
other side, also external to the main frame I enclose all the spur gearing; and
centrally within the main frame, I place the lifting sheave and its load chain in the
same plane with the suspension hook.
The improved checking and braking device consists of an annular recess in the
outer side of the adjacent side frame, within which recess is a casting or roller-ratchet
case, provided at its periphery with a series of excentric or cam shaped faces, to each
of which faces is applied a short cylindrical roller; the said rollers being confined to
their places by the outer convex wall of the said annular recess in the frame. The
said roller-ratchet case is free to revolve one way only along with its ratchet rollers,
and it has horns or lugs projecting outwardly to engage loosely with the rims of the
frictional discs, such as are referred to in the Specification of Patent No. 263 of 1863.
The said friction discs are engaged in part with the central driving shaft by the
intervention of a brake casting secured to the said shaft. The said brake casting also

page_text: carries by a screw thread on its central boss the driving pulley or sprocket wheel with
its endless hand chain whereby the machine is operated.
The aforesaid roller-ratchet checking device being self contained within one of the*
side frames as to all its strains, having only a loose driving engagement with the parts
checked from backward rotation, is obviously applicable to other machines, any parts
of which need to be checked in like manner against backward rotation.
The improved portable or suspended lift I have described, is obviously capable of use
when its supporting frame is a fixed one.
Having stated the nature of the invention I will now describe it more particularly,
with the aid of the annexed illustrative drawings.
Figure 1 is a side elevation of a geared pulley block or portable hoist, partly
sectional through the line a-a, Figure 2, with the friction discs removed.
Figure 2 is a longitudinal vertical section.
Figure 3 is another side elevation, the gear cover being removed to expose the
gearing and the rotary driving cage which supports the pivots of the planet pinions.
A, B, are two disc-formed framed sides united by three studs and nuts X X¹ X²,
the largest one X2 being fully shown in Figure 2. The crosshead C has attached to it
the suspension hook D. The trunnion ends C¹ of the crosshead are received in corre-
sponding holes or bearings one in each frame side. E is the load sheave, or lifting
sheave, toothed or recessed to engage with the load chain. The sheave E is integral.
with a hollow main shaft F, the latter being supported by bearings at each end in the
sides A, B, and at F2 the shaft F projects beyond the frame side B and is keyed to
the pinion frame or cage G wherein the pinion pivots G³ are fixed securely. The
three double pinions H, HI, are each of two diaineters cast in one piece. At their
larger diameter H they all engage with the central pinion I made integral with its
shaft I. At their smaller diameter H the said pinions all engage with the fixed
annular wheel K of the frame side B and integral therewith. The short cylinder
formed by the side B and the rim of the wheel K, is closed at its outer side by the
gear cover L.
The latter has a central boss L¹ thereon providing an end bearing for
the shaft and the said gear cover is attached to the frame side B by means of
screws L². The side frame A contains the improved frictional roller check wheel M
or ratchet roller check. Adjacent thereto is the driving pulley or sheave N. The
check wheel M is centred for rotation one way only, upon the boss. A¹ of the frame
side A and occupies the surrounding annular recess or enclosure, and around the outer
convex wall thereof, the rollers M' travel and upon it they also effect their lock or check'
action against backward motion by ascending slightly their respective eccentric
faces M in the periphery of the wheel M. The horns or short arms.M³ on the outer
side of the check wheel M engage loosely with the rim of the two brass friction
discs O such as are referred to in the Specification of Patent No. 263 of 1863. The
frictional connection of the discs O with the driving shaft I¹ is by means of frictional
action upon the outer face P2 of a brake casting or flange abutment P, also by the two
faces of the cast iron friction disc Q carried loosely by three lugs P¹ upon the flange P;
also by the inner frictional face N₁ of the sheave N. The flange P.is integral with a
sleeve P³ which latter is affixed to the shaft I¹ by a key 12 and the said sleeve is.
externally screw threaded for screw engagement with a corresponding thread central
in the sheave N. The co-action of the said screw threaded parts with the friction
discs, flange abutment P and shaft l' is based upon and fully explained in the Specifi-
cation of Patent No. 1867 of 1868. The disc Q on both faces, likewise the friction
face of the flange P and that of the sheave N, are helically grooved as shown
sectionally in Figure 2. The said grooves form oil reservoirs and distributors to the
friction surfaces and tend to equalize the wear thereon. This said grooved construction
of the discs is the subject of a separate application for Patent No.. 11,009. of 1890.
The engagement of the discs O with the arins Ms of the check wheel M leaves exposed
largely to the air, the edges of the discs, thus diminishing the tendency to heat accu-
mulation from their frictional duty. The driving shaft I is supported lengthwise and
rotates within the hollow shaft F. The driving pinion I is therefore solidly supported:
on each side between the last named bearing of its shaft I within the hollow shaft:

page_text: and the end bearing L' in the gear cover L. The same key 12 in the shaft I¹ which
secures thereto the flange P also secures the collar I³ the latter being further secured
in place by the nut I. R is a chain stripper or clearer to forcibly remove from the
recesses or link pockets in the load sheave E any links of the slack side of the load
chain which may temporarily cling to the sheave. S is a small casting the inner end S¹
of which serves as a chain guard or keeper to prevent the chain links of the slack side
of the chain from leaving the sheave prematurely, whilst its outer end S2 is a con-
venient point of attachment for the end of the slack chain. The parts R and S like
the cross head C are secured firmly between the frame sides A B by projections or
studs received into corresponding holes in the inside faces of the frame sides forming
a strong, simple and inexpensive method of uniting all the said parts C, R and S with
the main frame.
The operation is as follows:-
Upon applying force to the hand chain upon the sheave N in the direction for
hoisting the sheave N is at first advanced upon the screw thread of the sleeve P³ until
the discs are firmly compressed against the flange P. with a pressure determined by
the resistance of the load. The further continuance of the said hoisting force will
then rotate the shaft I', the discs, the flange P, the check wheel M, the pinion I, the
pinions H, H¹, the cage G, the shaft F and sheave E and thus lift the load. When the
hoisting force ceases all the said parts come to rest against the check wheel M locked
by its rollers to the frame side A. The reversed application of force to the hand
chain and sheave N unscrews the latter slightly against the now resisting check
wheel M and so soon as the said unscrewing has sufficiently reduced the frictional
adhesion of the disc faces, the shaft I' and all connected parts under the impulse of
the load follow the backward rotary motion of the sheave N so long as it is maintained
and cease with it as also fully explained in the Specification of Patent No. 1867 of
1868. The check wheel M embodies or is based upon a familiar mechanical movement,
but it will be noted that by this invention, the said check wheel is made an indepen-
dent rotary piece, integral neither with the piece it is designed to check nor with the
piece which furnishes the abutment, this latter being in the present case the frame
side A. The said check wheel is supported upon a boss or bearing A' on the frame
side A. The rollers M¹ exert their locking or jamming force upon the annular or
enclosing wall of the recess surrounding the boss A¹. The reaction is upon the said
boss. All the severe cam strains are therefore obviously self contained between the
opposed walls of the annular recess in the frame side and are thus kept from taking
effect upon any adjacent moving part and from all tendency to change the relative
position of any one part of the machine with any other. The improved check
device is therefore applicable to any machine requiring a similar continuous check
action. O
The invention as a whole can also obviously be applied to stationary hoists, or
embodied in a trolley frame moving upon the girders of a crane, or its frame may be
supported in any convenient manner.
I am aware that so called sun and planet gearing has been long employed in
hoisting machinery where compactness and power are needed, as also in capstans,
horse powers and other constructions, and that it has been proposed, but ineffectually,
to apply it to suspended hoists. To apply it however, successfully to portable hoists
or those of pulley, block type, it becomes necessary for safety, to unite with it the
common characteristic of that class of hoists; i.e.; that the load shall be self sus-
tained, as for example is the case in the well known differential pulley block
described in the Specification of Patent No. 1033 of 1859 by reason of its excessive
inherent friction: (*
Another necessity for such portable or suspended hoists is that the load sheave and
chain be central with their suspension line and the machine itself in equilibrium.
These features with others also desirable are organized together and embodied by this
invention in the manner herein before set forth, viz. A sun and planet spur geared
hoist of compact pulley block contour easy to handle; the gearing all enclosed; the
main sheave central to the suspension hook and closely supported on each side by the

page_text: side frames; the driving mechanism grouped exterior to the frame on both sides
thereof for syninetry and equilibrium; the checking apparatus automatic and con-
tinuous in action; the frictional brake apparatus durable and equable in action; the
latter operated without additional cords or levers by the hand hoisting chain alone;
the journals and bearing surfaces all of ample area; the structure extremely rigid.
and strong; the head room or vertical space necessary very small and the parts all of
convenient forin for manufacture.
Having now particularly described and ascertained the nature of the said
invention as communicated to me, I declare that what I claim is :-
1. The combination in a sun and planet geared portable hoist of pulley block type,
of an annular or internally toothed wheel external to the main frame and integral
therewith a main lifting or load sheave central in the machine and integral with a
rotatory hollow main shaft: the said hollow shaft journaled at each end in the frame,
and provided at its one end projected beyond the frame, with a flange or cage carrying
the planet pinions and a driving shatt passing centrally through the said hollow
shaft, substantially as herein before set forth and described.
:
2. The elements and construction set forth in claim 1, but the supporting frame of
the machine a fixed one.
3. In a sun and planet geared portable or suspended hoist, a rotatory cage or
supporting frame in one piece for the planet pinions, whereby the said planet pinion
pivots are supported at both ends, substantially as herein before described.
4. In a sun and planet geared hoist, the following three fold division or grouping of
the mechanism, viz. --First: Exterior to the main frame on one side the driving and
checking or brake devices. Secondly. Exterior to the main frame on the other side,
the train of sun and planet gearing, the annular wheel whereof is made integral with
that frame side and external to it. Thirdly: The load sheave or lifting sheave
placed centrally between the frame sides, all substantially as hereinbefore described.
5. The improved frictional check wheel and rollers, the said wheel constructed to
turn upon a boss of the frame or part containing it, and occupying an annular recess
or enclosure around the said boss or projected bearing and the said check wheel
having a loose driving connection with the other part checked or part against which
the check action is effected, all substantially as hereinbefore described.
6. In a hoisting machine the brake device whereof is provided with helical and
frictional surfaces, a frictional abutment flange P and central sleeve P' whereon is
formed the helix or screw thread adapted to the corresponding helix or screw thread
of the driving sheave or its equivalent part, substantially as hereinbefore described.
7. In a portable hoist provided with sun and planet gearing, a gear cover L having
therein centrally a bearing for the central driving shaft, substantially as hereinbefore
described.
8. In a portable sun and planet geared hoist, the planet pinions of two diameters,
the larger diameters whereof engage with the central driving or "sun" pinion and
the smaller diameters whereof engage with the annular wheel of the system of sun and
planet gearing, the said annular wheel being integral with the frame and external
thereto, substantially as hereinbefore described.
9. In a hoisting machine, the driving sheave provided with the frictional discs of
Patent No. 263 of 1863, with the operating helical inclines (or equivalent screw
threads) of Patent No. 1867 of 1868 and with the independent frictional check wheel,
all substantially as herein before described.
10. In a sun and planet geared hoist a main frame of disc form, the two main sides
or members of which are united with each other, and one member or frame side having
upon its exterior, and formed or otherwise made integral therewith the annular wheel
of the system of sun and planet gearing, substantially as and for the purpose
herein before described.