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Патент USA US3075629

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Jan. 29, 1963
s. T. BUCK
3,075,618
ACTUATING MECHANISM FOR I-IOISTING MACHINE
Filed July 22, 1960
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INVEN TOR.
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By?‘f?o
ATTO RNEYS.
Jan. 29, 1963
3,075,618
S. T. BUCK
ACTUATING MECHANISM FOR HOISTING MACHINE
Filed July 22, 1960
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Jan. 29, 1963
s. T. BUCK
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ACTUATING MECHANISM FOR HOISTING MACHINE
Filed July 22, 1960
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IN VEN TOR.
BY 577.? Am 7.“ Eve/c,
'
’ ?ay/4w
ATTORN 5V5
United States Patent'O ” ICC
1
3,075,618
ACTUATING MECHANISM FOR HOISTING
MACHINE
Steward T. Buck, % Buck Equipment Corp, 720 Ander
son Ferry Road, Cincinnati, Ohio
Filed .Iuly 22, 1960, Ser. No. 44,599
11 Claims. (Cl. 187-32)
3,075,618
Patented Jan. 29, 1963
2
FIGURE 6 is an enlarged side elevational view with
parts broken away of the brake shoe assembly, illustrat
ing the manner in which it is actuated by the cam means.
FIGURE 7 is a vertical cross sectional view illustrating
the general layout of the clutch and brake mechanism.
FIGURE 8 is an enlarged side elevational view of the
cam Wheel which control the position of the cam shaft
and cam segments for actuating the brake and clutch
shoes.
This invention relates to hoisting machines of the type
FIGURES 9 and 10 she side elevational views of brake
used on construction jobs and the like to raise supplies 10
and clutch actuating cams.
and equipment to the upper stories of a building or other
Referring ?rst to FIGURE 1 of the drawings, I have
elevated work site. While such hoisting machines may
therein illustrated a portable hoisting machine with which
take various forms, they usually comprise a tower pro
the actuating mechanism of the instant invention may
vided wit-h vertically extending guideways or tracks along
which a lift platform is adapted to be moved, the lift 15 be employed. Essentially, the machine comprises a base
or frame 1 mounting a vertically extending tower 2 along
platform being raised and lowered by means of a cable
which the lift platform or other lifting means 3 is adapted
one end of which is wound on the drum of a hoist having
a prime mover and clutch mechanism for selectively ro
tating the drum in opposite directions to raise and lower
to travel, the lift platform having grooved rollers 4
adapted to move along guide rails or tracks 5 forming
20 a part of the tower structure. The lift platform is adapted
the lift platform.
to be raised and lowered, as from the position shown in
In my copending application Serial No. 761,186, ?led
solid lines at the bottom of the ?gure to the position
September 15, 11958, and entitled “Automatic Control Sys—
shown in dotted lines at the top thereof, by means of a lift
tern for Hoisting Machine,” I have taught the provision
cable 6 which extends upwardly from the hoist mecha
of a hoisting machine ‘of the general type just character
ized which incorporates an automatic control system for 25 nism 7 around a pulley 8 at the top of the tower and then
downwardly for attachment to the lift platform. The
starting and stopping the lift platform at predetermined
base or frame 1 of the device may be provided with re
upper and lower positions, the machine operator having
tractable wheels 9 'by means of which the device may be
only to start the platform on its upward or downward
readily transported from place to place; and to facilitate
journey whereupon the control system, which is elec
trically controlled, takes over to stop the lift platform 30 such transportation, the tower is preferably formed as
‘a plurality of hinged sections joined together by means
at a pre-set position. While such automatic system has
of hinges 10. Collapsible towers of this character are dis
proven to be highly successful, the mechanism is never
closed in my Patent No. 2,653,685 dated September 29,
theless relatively expensive and there is a decided need in
1953 and entitled Portable Hoisting Tower, and reference
the industry for a less expensive, preferably non-elec
tronic mechanism for controlling the up and down move 35 is made to the patent for details of the construction and
mode of erecting and collapsing the tower structure.
ment of the lift platform.
However, it should be understood from the outset that
Accordingly, a principal object of the instant inven
the particular form of tower structure does not constitute
tion is the provision of actuating and control mechanism
for a hoisting machine which is of relatively simple and 40 a limitation upon the instant invention since the actuating
mechanism to be hereinafter described is applicable to
inexpensive construction and yet enables the operator to
diverse types of devices, whether they be of portable char
pre-set the level at which the lift platform will be stopped,
acter or erected on the job in a piece by piece assembly.
thereby relieving him for other duties.
Referring now to FIGURE 4, the base or frame 1
A further object of the instant invention is the provi
mounts a prime mover 11, which generally comprises an
sion of actuating and control mechanism for a hoisting
internal combustion engine the drive shaft of which is
machine which is positive in action and in which me
operatively connected, as by means of the chain drive 12,
chanical means are employed to control the starting and
to the hoist mechanism 7 which includes a drum shaft
stopping of the hoist mechanism to the elimination of the
13 to which the drum 14 for the lift cable 6 is secured.
more costly electronic controls of the system taught in
The shaft 13 also mounts a clutch mechanism 15 opera
the aforementioned application.
tively connected to the chain drive 12; and a brake mech
The foregoing together with other objects of the in
anism 16 is also provided for locking the cable drum 14
vention which will appear hereinafter or which will be
against rotation. If desired, the drum shaft 13 may also
apparent to the skilled worker in the art upon reading
be provided with a power take-off 17 and/or a work
head 18.
The actuating and control mechanism for the hoist
plary embodiments.
comprises a cam shaft 19 provided at one end with a
Reference is now made to the ?gures of the drawings
control wheel 20 and its opposite end with a control cam
wherein:
21 by means of which the cam shaft may be releasably
FIGURE 1 is a side elevational view of a portable
hoisting machine with the tower in its elevated position. 60 secured in its various positions of use. The cam shaft
19 mounts a series of cams, which will be described in
FIGURE 2 is an enlarged fragmentary plan view of
detail hereinafter, by means of which the brake mecha
the selector disc for selectively engaging the clamps on
nism I6 is engaged and released and the clutch mecha
the control cable.
nism 15 activated to either raise or lower the lift plat
FIGURE 3 is a side elevational view with certain parts
form depending upon the direction of rotation of the
shown in dotted lines of the selector disc assembly of
cable drum 14.
FIGURE 2.
Essentially, the cam shaft 19 has three positions of use.
FIGURE 4 is a plan view of the hoist mechanism show
The ?rst comprises an intermediate or neutral position
ing the clutch and brake assembly together with its actu
in which the brake mechanism 16 is locked and both the
ating means.
FIGURE 5 is an enlarged fragmentary and elevational 70 “up” and “down” components of the clutch mechanism 15'
are disengaged. From the neutral position, the cam shaft
view of the clutch and brake mechanism and the cam
may be rocked in either a clockwise or a counter-clock
means for actuating them.
these speci?cations, I accomplish by that construction and
arrangement of parts which I shall now describe in exem
3,076,618
3
4
wise manner; rotation or rocking movement in one direc
through the opening 31a and continued upward move
tion serving to engage the “up” component of the clutch
mechanism while at the same time releasing the brake,
whereas rocking movement in the opposite direction
ment of the lift platform will draw the cable with it,
thereby causing the control wheel 20 to be rotated. Such
rotation acts to disengage the “up” component of the
serves to engage the “down” component of the clutch
mechanism and also serves to release the brake. Rock
ing movement of the cam shaft is effective by means of a
clutch and set the brake, thereby arresting the upward
movement of the lift platform at'a predetermined ele
control cable 22 secured to the control wheel 20.
As seen in FIGURE 1, the control cable 22 extends
vation. It will be understood, .of course, that such pre
determined elevation may be varied -by adjusting thepo
sition of the cable clamps 25 along the control cable 22.
from control wheel 20 to a pulley wheel or sheave 23 lo 10 If the lift platform is to be raised to the position estab
cated 'at the lower end of the tower 2 adjacent the lift
lished by the cable clamp 25c,'then the selector disc will
platform 3, the cable then extending upwardly along the
be set so that the opening 31c surrounds the cable. The
tower in close promixity to the path of travel of the lift
diameter of the opening 310 is such that it will permit
platform, the control cable passing around one or more
the lowermost cable clamp 25a to pass freely there
pulley wheels 24 at the upper end of the tower and then 15 through, as will the next cable clamp 2512; but the cable
returning downwardly to the control ‘wheel 20. Prefer
clamp 250 will be engaged and retained, whereupon the
ably, the control cable 22 is in the form of an endless
cable willbe lifted to disengage the “up” component of
band one portion of which is wrapped about a periphery
the hoist mechanism.
of the control wheel-—which may be grooved for this pur
It will be understood that the upward movement of
pose—the cable being cleated or otherwise ?xedly se 20 ‘the lift platform 3 will be initiated by rocking the cam
cured to the control wheel. With this arrangement, the
shaft 19 to clutch engaging position. This may be done
control cable will have a limited movement in opposite
by means of a hand grip 35 secured to the return ?ight
directions, the extent of such movement being determined
of the control cable 22 in ‘a position where it may be
'by the degree of rotative movement required to move
readily grasped by the machine operator. If desired, the
the cam shaft 19 from the neutral position to either of the 25 ‘opposite end of the cam shaft 19 may be provided with a
‘operating positions. It will be apparent that the control
‘secondpcontrol wheel 36' which may be utilized to ‘actu
wheel 2%} may be turned so as to rock the cam shaft by
‘ate the hoist mechanism from the ‘opposite side of the ma
engaging and pulling on the control cable at any point
‘chine.’ Such second'control‘wheel may be provided with
along its length.
_
a ‘crank handle 37 and, if desired, a second control cable
Spaced along that portion of the control cable which 30 22a ‘may extend upwardly from the control wheel 36 in
‘parallels the path of travel of the lift platform 3 are a
much the same manner as‘ the cable 22, although the sec~
plurality of cable clamps 25, which are of successively
*ond cable need not be provided with the cable clamps 25.
From the foregoing it should be apparent that the
larger diameter, with the smallest diameter clamp 25a
"lowermost and the successively larger diameter clamps
downward movement of the lift platform may be ‘con
25b 25c and 25d spaced upwardly along the control
trolled in similar fashion to the upward movement thereof
‘cable. 'These clamps are adapted to be selectively en
‘by suitably adjusting-theselector ‘disc to either pass or
gaged by a cable follower 26 mounted on the lift platform
stop the various cable clamps. The bottom or down po
3,‘ the cable follower surrounding and moving along the
sition of the lift platform may be’ permanently ?xed by
control cable as the lift platform moves up and down
‘means of ‘a cable clamp 2512 which will bed a diameter
along the tower. As best seen in ‘FIGURES 2 and 3, the 40 larger than any of the openings 31 in the selector disc.
cable follower 26 is provided with a mounting arm 27 by
As'seen in FIGURE 3, the cable clamps v25 will'prefcr
means of which it may be readily secured to the ‘lift plat
ably have a cylindrical center portion 38 terminating in
form, the follower being provided with an irregular slot
28 through which the control cable is adapted 'to be
conical end portions 39 by means of which the clamps
will be guided through the openings 29 and 31. In the
vpassed, the inner end of the slot 28 terminating in an 45 case of the clamps de?ning'the upper and lower limits of
annular opening 29 through which the vseveral cable
clamps 25 may freely pass, with the possible exception
of the uppermost cable clamp 25d. The cable follower
also mounts a rotatable selector disc 30 having a pin
rality of open'ingsg31 therein of successively larger di
ameter adapted to be selectively juxtaposed to the open
ing 29. It will be noted that each ‘of the openings 31a,
"31b, 31c and 31d has a neck portion 32 opening out
wardly to the periphery of the selector disc 30, the neck
portions 32 being arranged to be aligned with the irregu 55
~l-ar' slot 23 so that the control cable may be initially intro
T'duced-‘therein, whereuponthe necks 32 may be offset with
respect to the slot 28, as will be clear from FIGURE 2,
travel, the conical portions 39v facing the openings may be
eliminated since at no time do these clamps pass through
‘the selector disc.
it is ‘also desirable to provide the selector disc assembly
with a manually controlled cable locking device to‘ pre
vent accident-ail actuation of the control mechanism. To
"this end, the cable follower 26 may mount a block 40 to
which an arm 41 is slidably secured, the arm being mov
able horizontally from the position illustrated in solid
lines in FIGURE '3 to-the position illustrated in dotted
‘lines. The ‘arm 41 is provided with a generally V-shaped
notch 42 which, when‘the arm‘isin the extended position,
receives the control cable 22 and overlies the cable clamp
25 engaged by the selector disc. The cable clamp is thus
2thereby assuring retention of the control cable within the
‘con?nes of the selected opening 31. A spring biased de 60
effectively retained between the selector disc and the arm
tent 33 is preferably provided coacting with depressions
and movement of the cable is prevented. Thus, if a per-1
34 in the unde'rsurface of the disc 30 to align the several
son ‘is loading the lift platform-at an upper level, by ex
jopeningsl? with respect to the opening 29.
tending the arm 41 the control cable is ?xed‘ against move
The diameter of the openings-31 are correlated to the
“diameters of the cable clamps 25 so as to pass or stop 65 ment so that-the hoist operator on the ground could not
inadvertently start the lift platform and endanger the per
‘the cable clamps as the lift platform moves along the
’son loading it. The arm 41 may be conveniently actuated
‘tower with the cable follower in engagement with the
by means of a' ?nger grip43,tthe arm having an elongated
icontrol cable. In the embodiment illustrated there are
four cable clamps and four openings in the selector disc.
slot 44 therein movable relative to the studs-45 and re
The smallest opening 31a in the selector disc is of a di 70 tained in the rettr-acted'or extended position by means of
ameter smaller than the diameter ofthe lowermost cable
spring detent "46 engageable in depressions or the like 47
clamp 25a, so that, when the-opening 31a is juxtaposed
to the opening 29 in the cable follower and the lift plat
form moves upwardly from its lowermost position, the
‘cable clamp 25a will contact but will beunabletopass
in the undersurface of the arm.
Referring now totFIGURE 7 of the drawings, the clutch
:mechanism 15lcomprisesa planetary‘lgear system of known
character having va clutch wheel-‘I50Jforming a part- of ‘the
3,075,618
5
“down” component of the system, and a rotatable housing
51 forming a part of the “up” component of the system.
A clutch band 52 surrounds the clutch wheel 56 and a
similar clutch band 53 surrounds the rotatable housing 51,
the clutch bands acting in a manner to be fully explained
hereinafter to selectively lock the clutch wheel and/or
housing against rotation or free them for rotation, depend
the cam followers 75, 75a mounted on the yokes in the
manner seen in FIGURES 5 and 6.
The cam followers 75, 75a for each of the- bands 52,
55 and 64 are positioned to engage cams 76, 77 and 73,
respectively, mounted on cam shaft 19 and rotatable there
by. The brake cam '78 is illustrated in FIGURE 9; where
as FIGURE 10 illustrates one of the clutch cams, such
as the cams 77, the two clutch earns being of identical con
?guration. The cam 78 will be positioned on the cam
The shaft 13 is driven by means of the sun gear 54 1O shaft 19 in such fashion that the set of cam followers 75,
75a will lie in the depressions 78a when the cam shaft
which is keyed to the shaft and positioned for engagement
is in its neutral position; and the clutch cams 76 and 77
with the gear clusters 55 and 55a each of which is corn~
will be arranged in such fashion that the cam followers
posed of three gears keyed together for joint rotation
will be contacted by the rise portions, such as the per
about their common shafts 56 and 56a mounted in the
tions 77a, when the cam shaft is rotated to neutral posi
rotatable housing 51. An end-most gear in each cluster
tion.
is in meshing engagement with sun gear 54, whereas the
The cam shaft 19 is maintained in its several posi
intermediate gear of each cluster is in engagement with a
tions of use by means of the control cam 21 which, as
gear head 57 secured to a rotatable sleeve 58 the opposite
will be seen in FIGURE ‘8, is provided with a pair of
end of which mounts a sprocket 59 which is engaged by
the chain drive 12 from the prime mover 11. The remain 20 spaced apart pockets 79 and 3t} adapted to be engaged
by a cam follower ‘81 mounted between the arms of a
ing gear in each cluster engages the gear head on secured
yoke ‘32, the arms of the yoke each having an elon
‘to the hub 61 of the clutch wheel 59, the hub 61 being
gated slot S3 therein through which the cam shaft 19 is
mounted for rotation relative to the sleeve 58 which it
arranged to pass, the arms of the yoke lying on oppo
surrounds.
With the arrangement just described, the shaft 13 will 25 site sides of the control cam 21. The yoke 82 is se
cured to an end plate 84 of a sleeve ‘85 which is tele
remain stationary when both clutch wheel 5% and housing
scopically received by a second sleeve 86 the lowermost
51 are free to rotate, i.e. when the clutch bands 52 and
end of which is closed by a plate 87 mounting an at
53 are disengaged. However, when the clutch band 52 is
tachment ear ‘38. A compression spring 89 is enclosed
contracted so as to engage and secure the clutch wheel 50
within the telescoping sleeves ‘85 and 86, the spring
against rotation, the sun gear 54 will be rotated in one
serving to resiliently bias the cam follower 81 toward
direction due to the action of the gear clusters. When, on
the periphery of the control cam 21. It will be under~
the other hand, the housing 51 is held against rotation and
stood that the attachment car '83 will be secured to a
the ‘clutch wheel 56) is free to rotate, the gear head 57 will
fixed mounting forming a part of the machine frame.
act through the intermediate gear in each cluster to drive
When the control shaft 19 is in its intermediate or
the sun gear in the opposite direction. Normally, the
neutral position, the cam follower v81 will ride along
clutch wheel 50 comprises the “down” component of the
gear system ‘and the rotatable housing 51 comprises the
the intermediate segment 90 of the control cam, but
“up” component. Thus, when the rotatable housing 51
when the cam shaft is rotated, the cam follower 81 will
:ing upon the direction in which the drive shaft 13 is to
be driven.
is held against rotation, the lift cable will be wound onto
engage one or the other of the pockets 79, 80, thereby
the drum 14; whereas when the clutch wheel so is held 40 securing the cam shaft in the rotated position. How
ever, when positive turning force is applied to the cam
against rotation, the cable will be payed out from the
shaft, as when the control cable 22 is actuated, the re
drum.
It will be noted from FIGURE 7 that one end of the
sistance of spring 89 will be overcome and the cam
drum 14 comprises a drum ?ange 6-2 the periphery of
follower ‘31 will be released from the pocket and the
which de?nes a brake drum 63 coacting with a brake band 45 control cam 21 will be free to return to the neutral po
64. The brake band is adapted to enga» e the brake drum
sition.
63 and lock the ‘cable drum 14 against rotation when the
As should now be apparent, the instant mechanism
‘clutch components are both released, i.e. when the actuat~
provides positive control over the operation of the de
ing mechanism is in the neutral position. However, when
the actuating mechanisn1-which comprises the cam shaft
19, and the control wheel 26 and the control cam 21-——
is moved to either of the operating positions to thereby
vice, the clutch and brake mechanism being controlled
by movement of the cam shaft 19 which, in turn, is un
der the control of the control cable 22. Preferably,
the positioning of the clutch cams 76 and 77 relative to
engage one or the other of the clutch bands 52, 53, the
the brake cam 78 will be such that the selected clutch
brake band 64 will be disengaged so as to free the cable
band will be engaged slightly in advance of the release
55 of the brake band, thereby assuring that the winch will
drum for rotation.
As a practical matter, the clutch bands 52, 53 and the
at all times be under the positive control of one or the
brake band 64 are of identical construction and, as will
other of the components. Similarly, the brake band
be evident from FIGURES 5 and 6, are actuated by iden
will be set to engage momentarily before the release of
tical mechanism. Thus, as possibly best seen in FIGURE
a given clutch band when the cam shaft is moved from
6, each of the bands is composed of an upper shoe 65 and 60 the operative to the neutral position. As an added safety
a lower shoe 66 each pivoted at one end to the shaft 67
factor, it is preferred to provide a centrifugal clutch on
by
65
7t}
70
means of hinges 6-8. At their opposite ends the shoes
and 66 mount yoke adapters 69 to which the yokes
and 70a are adju-stably secured. Each pair of yokes
and 70a is joined together by -a pair of rods 7 ll, '72 pro
vided with springs '73 surrounding the rods and arranged
to urge the yokes towards each other, thereby clamping
the drive shaft of the prime mover, particularly where
an internal combustion engine is employed, to control
the downward speed of the lift platform under condi
tions of heavy load. Such clutch will serve as a brake
on the engine should it tend to run away under the heavy
load.
the shoes against the drum or wheel with which they are
Modi?cations may be made in the invention without
associated. Adjustment nuts 74 are provided to vary the
compression of the springs 73 so that the clamping pres— 70 departing from its spirit and purpose. For example, if
it is desired to control both the “up” and “down” move—
sure of the band may be adjusted as required. The bands
ment of the lift platform, that is, provide adjustable
are thus biased toward the contracted or set position by
settings for the lift platform as it travels downwardly
'the springs 73 and are expanded or released by means of
from the top of the tower, the control cable 22a at the
the cams mounted on the cam shaft 19, the cams being
arranged, upon rotation of the cam shaft 19, to engage 75 opposite side of the tower could be provided with a set
3,075,618
7
8
of clamps arranged in reverse order to those on con
clutch and brake means, a control wheel ‘at one end of
trol cable 22, i.e. smallest diameter clamp uppermost,
and the lift platform provided with a second cable fol
lower and selector assembly positioned for engagement
by the cable 22a.
said cam shaft, a control cable extending vertically along
said tower in alignment with the path of travel of said
lift platform, said control cable ‘being operatively con
nected to said control wheel and arranged so that length
wise movement of the control cable in either direction
Other modi?cations will undoubtedly occur to the
skilled worker in the art upon reading this speci?cation,
and consequently I do not intend to limit the invention
will act to rotate said control wheel and the cam shaft
on which it is mounted, a plurality ‘of cable clamps se
cured to said ‘control cable at spaced apart intervals, con
excepting in the manner set forth in the claims which fol
low. What I desire to secure and protect by Letters 10 trol cable engaging means associated with said 'liftplat
form for selectively engaging pre-determined clamps on
Patent is:
said control cable as said lift platform moves up and
1. In a hoisting machine having a vertical tower
down along said tower, a control cam mounted on said cam
along which a lift platform is raised and lowered by
shaft, said control cam having a plurality of spaced apart
means of a winch and cable, actuating mechanism for
pockets therein adapted to be selectively engaged by a
controlling the movement of said winch and cable, said
cam follower, depending upon the direction of rotation of
mechanism comprising clutch means having an “up”
said cam shaft, whereby to releasably lock said cam shaft
component and a “down” component operatively con
in a pre-determined position of use.
nected to said winch, and also brake means operatively
6. The device claimed in claim 5 wherein said control
connected to said winch, the improvement which com
prises control means for selectively actuating said brake ' cable is an endless cable one portion of which is looped
‘about said control wheel and ?xedly secured thereto.
and clutch means, said control means comprising a ro
7. The device claimed in claim 6 wherein the cam fol
tatable cam shaft mounting a plurality of cams arranged,
lower for said control cam is spring biased toward the
upon rotation of cam vshaft, to selectively engage and
periphery of said control cam.
‘release said clutch and brake means, a control cable ex—
8. The device claimed in claim 7 wherein said control
‘tending vertically along said tower in alignment with 25
cam has an intermediate or neutral position in which said
the path of travel in said lift platform, said control cable
brake means is set and said clutch components are re
being operatively connected to said cam shaft so that
leased, said control cam being movable in opposite direc
lengthwise movement of said control cable will act to
rotate said cam shaft, a plurality of cable clamps se
tions to “up” and “down” positions in which said brake
cured to said control cable at spaced apart intervals, 30 means is released and one or the other of said clutch
and control cable engaging means associated with said
lift platform for selectively engaging pre-determined
‘clamps on said control cable as said lift platform moves
up and down along said tower, whereby, upon engage
ment of a pre-determined clamp by said cable engag- '
ving means, said control cable will be moved lengthwise
-to thereby actuate said clutch and brake means.
2. The device claimed in claim 1 wherein adjacent
cable clamps are of progressively larger diameter, and
‘wherein said control cable engaging means comprises an
adjustable selector having a plurality of control cable
receiving openings therein of progressively larger diam
eter.
3. The device claimed in claim 2 wherein said selec
'tor comprises a rotatable vdisc, and wherein means are
provided to releasably secure said disc in predetermined
position.
4. The device claimed in claim 3 wherein said selec
components engaged, depending upon the direction-of ro
tation of said control cam, the pockets in said control
cam being positioned to releasably retain said control cam
in the “up” or “down” positions.
9. In a hoisting machine having a vertical tower along
which a lift platform is raised and lowered by means of
a winch and cable, a drive shaft for said winch, clutch
means having an “up” component and ‘a “down” com
ponent operatively connected to said drive shaft, means
connecting said clutch mechanism to a prime mover,
brake means operatively connected to said drive shaft,
the “up” and “down” components of said clutch means
each having an external clutch drum engageable by co
‘acting pairs of clutch shoes, said brake means including
a brake drum engageable by brake shoes, spring means
normally biasing said clutch and brake shoes to drum
engaging position, control means for selectively releasing
said clutch and brake shoes, said control means compris
ing a rotatable cam shaft mounting a plurality of cams
tor disc is mounted on a'cable follower having an open
arranged, upon rotation of cam shaft, to selectively en
50
ing therein of a diameter at least as great as the largest
.gage and expand said clutch and brake shoes, a control
opening in said selector disc, and wherein an irregular
'slot opens into the opening in said cable follower, each
vof the openings in said selector disc having a neck por
‘tion adapted to be aligned with the said slot to permit
the control cable to be concurrently introduced into a
selected opening in said selector disc and the underlying
‘Opening in said cable follower, said last named open
ings being in non-concentric but overlapping relation
cable extending vertically along said tower in alignment
with the path of travel of said lift platform, said control
cable being operatively connected to said cam shaft so
that lengthwise movement of said control cable will act
to rotate said cam shaft, a plurality of cable clamps se
cured to said control cable at spaced apart intervals, and
control cable engaging means associated with said lift plat
form for selectively engaging pre-determined clamps on
when said neck portion and slot are in alignment, and
said control cable as said lift platform moves up and
said neck portion and slot being in the non-overlying re
down along said tower, whereby, upon engagement of a
lation when said last named openings are in concentric
pre-determined clamp by said cable engaging means, said
relation.
control cable will be moved lengthwise to thereby actu
5. In a hoisting machine having ‘a vertical tower along
ate said clutch and brake shoes.
“which a lift platform is raised and lowered by means of
10. The device claimed in claim 9 wherein said cam
.a winch and cable, actuating mechanism for controlling
shaft has an intermediate or neutral position in which
the movement of said Winchand cable, said mechanism
said brake shoes are engaged and said clutch shoes are
comprising clutch means having an “up” component and
released, said cam shaft being movable in opposite direc
.a “down” component operatively connected to said winch,
tions to “up” and “down” positions in which said brake
and also brake means operatively connected to said 70 shoes are released and the said pairs of clutch shoes se
winch, the improvement which comprises'control means
lectively released depending upon theidirection of rotation
.for selectively actuating said brake and clutch means,
of said cam shaft.
said control means comprising a rotatable cam shaft
11. The device claimed in claim 10 wherein the con
tours of said clutch and brake shoe actuating cams are
mounting a plurality of cams ‘arranged, upon rotation-of
said cam shaft, to selectively engage and release said 75 such that the clutch shoe willibe engaged slightly in ad
3,075,618
10
vance of the a'elease of said ibrake shoes, and vice-lversa,
344,307
Grovan _____________ __ June 22, 1886
whereby said device will be at all times under the positive
1,023,857
Lathrop ____________ __ Apr. 23, 1912
control of either said brake means or said clutch means-
1,038,020
Sturm ______________ __ Sept. 10, 1912
1,586,768
Allen ________________ __ June 1,
1,599,938
2,001,674
Zette?und _________ __ Sept 14, 1926
Erickson ____________ __ May 14, 1935
2,653,685
Buck _______________ __ Sept. 29, 1953
_
_
_
References Cited 1n the ?le of th1s patent
UNITED STATES PATENTS
264,745
Peare _______________ __._ Sept. 19, 1882
5
1926
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