U.S. patent number 3,612,330 [Application Number 04/857,117] was granted by the patent office on 1971-10-12 for hoist mechanism.
This patent grant is currently assigned to Allied Products Corporation. Invention is credited to Austin R. Baer.
United States Patent |
3,612,330 |
Baer |
October 12, 1971 |
HOIST MECHANISM
Abstract
The hoist mechanism includes four winches which are mounted on
the base of a frame structure having upstanding supports on the
base. The winches are connected to a common drive shaft rotatably
mounted on the base. A pair of upper and lower guide rollers are
associated with each of the winches and are mounted on the
upstanding supports. Each winch has a length of cable, a portion of
which is wound on the winch and a portion of which is trained over
the guide rollers and then secured to one corner of a panel which
is horizontally disposed over the base. Each cable is trained over
a movable sheave assembly which is resiliently biased to place
tension on the cable. A slip clutch is located in the drive
connection between the drive shaft and each winch to stop rotation
of each winch when a predetermined tension is placed on each cable
wound on each winch, such as when a corner reaches its upward limit
of travel.
Inventors: |
Baer; Austin R. (Elmhurst,
IL) |
Assignee: |
Allied Products Corporation
(Chicago, IL)
|
Family
ID: |
25325227 |
Appl.
No.: |
04/857,117 |
Filed: |
September 11, 1969 |
Current U.S.
Class: |
220/1.5;
74/89.22; 220/6 |
Current CPC
Class: |
B65D
88/524 (20130101); Y10T 74/18848 (20150115) |
Current International
Class: |
B65D
88/52 (20060101); B65D 88/00 (20060101); B65d
007/26 (); B65j 001/02 () |
Field of
Search: |
;220/1.5,6,7
;254/144,173 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Lowrance; George E.
Claims
I claim:
1. A mechanism for raising and lowering a panel or like member on a
frame structure which includes a base and upstanding support means,
said mechanism comprising at least three winches which are mounted
on said base and which are operatively connected to a common drive
means, a pair of upper and lower guide means associated with each
of said winches and mounted on said upstanding support means, a
length of cable associated with each of said winches and having one
portion thereof coiled on its associated winch and another portion
which is trained over said guide means associated with said winch,
each of said cables having a first end anchored to its associated
winch and a second end which is connected to said panel, said
second ends of said cables being connected to said panel at spaced
apart locations thereon, torque responsive means associated with
each of said winches for stopping rotation of the associated winch
when a predetermined tension is placed on said cable anchored to
said associated winch, and tensioning means for continuously
applying tension to each of said cables to prevent slack from
developing at any time in any one of said cables.
2. The mechanism as defined in claim 1 wherein said torque
responsive means includes a slip clutch in the drive connection
from said drive means to said winch.
3. The mechanism as defined in claim 1 wherein said upstanding
support means includes four upstanding corner posts, four winches
are mounted on said base, and said frame structure is part of a
collapsible container, said panel forming the roof for said
container and said container including first and second oppositely
facing sidewalls hingedly connected to said base and said roof and
first and second end walls pivotally connected to said base, each
of said endwalls including two of said upright corner posts with
panel means therebetween.
4. The mechanism as defined in claim 1 wherein said tensioning
means includes a spring means having a fixed end and a free end,
said fixed end being connected to said base, a sheave assembly
including a pulley block connected to said free end of said spring
means and a pulley mounted on said pulley block, said cable being
trained over said pulley and said sheave assembly being adapted to
move transversely of the axis of rotation of said pulley against
the tension of said spring means when tension on said cable is
increased and decreased.
5. The mechanism as defined in claim 4 wherein said tensioning
means includes a guideway which guidingly receives a portion of
said pulley block and said spring means, said guideway having stop
means positioned to limit movement of said pulley block.
6. In a collapsible container of the type having a base, end walls
pivotally connected to said base, sidewalls hingedly connected to
said base and a roof panel hingedly connected at each side edge
thereof to said sidewalls, the improvement comprising a hoist
mechanism mounted in said base and including a plurality of
winches, a cable secured at one end to each of said winches and
having a portion extending to said end walls, upper and lower guide
means on said end walls for guiding portions of each of said cables
to the top of said end walls, said cables having end portions which
extend from said top of said end walls to said roof and are secured
to said roof at spaced apart locations thereon, and means for
rotating said winches from outside of said container, said hoist
mechanism providing a self-contained means within said container
for raising and lowering said roof and said sidewalls connected to
said roof between an erected condition and a collapsed condition of
said container.
7. The hoist mechanism as defined in claim 6 including torque
responsive means associated with each of said winches for stopping
rotation of each of said winches when a predetermined tension is
placed on one of said cables connected to one of said winches.
8. The hoist mechanism as defined in claim 6 including tensioning
means for continuously applying tension to each of said cables to
prevent slack from developing at any time at any one of said
cables.
Description
The present invention relates to a hoist mechanism for raising and
lowering a horizontally disposed panel, such as a roof panel of a
collapsible container, on a frame structure which includes a base
and upstanding supports. As such, the present invention provides a
simple and compact hoist mechanism including a plurality of cables
which are fixed to the horizontally disposed panel at spaced apart
locations thereon, Each of the cables is trained over upper and
lower guide rollers on the upstanding supports and then wound on a
winch. The winches are driven by a common drive shaft. To minimize
misalignment of the panel when it is raised and lowered and to
limit the tension placed on the cables, each of the winches has a
slip clutch associated therewith. When the tension on one of the
cables reaches a certain point, the clutch associated with the
winch on which the one cable is wound will slip and further
rotation of the winch is prevented. To minimize sway when raising
and lowering the panel and to minimize slack in the cables when the
panel is in a fully raised position or a fully lowered position, a
spring tensioning device is associated with each winch on each
cable for maintaining tension on each of the cables in all
positions of the panel.
A general object of the present invention is the provision of a
simple and inexpensive hoist mechanism for raising and lowering a
horizontally disposed panel.
Another object of the present invention is the provision of a hoist
mechanism for raising and lowering a horizontally disposed panel in
which little, if any, sway or misalignment of the panel is
encountered during the raising and lowering thereof.
Another object of the present invention is the provision of a hoist
mechanism for raising a roof panel of a collapsible container.
Another object of the present invention is the provision of a hoist
mechanism for raising and lowering a horizontally disposed panel in
which proper vertical translation of the panel between a fully
lowered position and a fully raised position over a period of
continued use of the hoist mechanism is ensured.
Another object of the present invention is the provision of a hoist
mechanism for raising and lowering a horizontally disposed panel by
means of a plurality of cables connected to the panel wherein the
length of each cable is maintained uniform during raising and
lowering of the panel.
Another object of the present invention is the provision of a hoist
mechanism for raising and lowering a horizontally disposed panel
wherein each corner of the panel is raised to its upward limit of
travel so that each corner, after the panel is raised, will be in
proper position to be locked in place without placing excessive
tension on any one of the cables.
Another object of the present invention is the provision of a hoist
mechanism for raising and lowering a horizontally disposed panel by
means of a plurality of cables connected to the panel wherein
tension is maintained on all of the cables in all positions of the
panel to prevent slack from developing in any one of the
cables.
Another object of the present invention is the provision of a hoist
mechanism for raising and lowering a horizontally disposed panel by
means of a plurality of cables connected to the panel wherein each
cable is connected to a winch and the maximum tension is limited to
a predetermined value to prevent damage to the cables.
Still another object of the present invention is the provision of a
mechanism for raising and lowering a horizontally disposed panel by
means of a plurality of cables each connected to the panel wherein
each cable is connected to a winch and the winches are driven in
synchronous relationship by a common drive shaft.
These and other objects and advantages of the present invention,
and the manner of their attainment, will become apparent from the
following description of a preferred embodiment of the invention
taken in conjunction with the accompanying drawings wherein:
FIG. 1 is perspective view of a collapsible container in its
erected condition on which the present invention may be
incorporated and practiced,
FIG. 2 is a perspective view of the collapsible container in a
partially erected condition and showing three of the cables of the
hoist mechanism of the present invention;
FIG. 3 is a perspective view of the collapsible container in the
fully collapsed condition;
FIG. 4 is a perspective view of the collapsible container in a
partially erected condition with the end panels and portions of the
roof and sidewall panels removed;
FIG. 5 is a partially schematic view of the winches and drive shaft
of the hoist mechanism of the present invention mounted in the
floor of the collapsible container;
FIG. 6 is an enlarged sectional view taken along lines 6--6 of FIG.
5 and showing the spring biased sheave assembly associated with one
of the cables of the hoist mechanism shown in FIG. 5;
FIG. 7 is a fragmentary schematic view of one cable of the hoist
mechanism of the present invention trained over pulleys on a
pivotally mounted corner post in a vertical position; and,
FIG. 8 is a schematic view similar to FIG. 7 and showing the corner
post rotated to a position between the vertical position and a
horizontal position of the corner post.
Referring now to the drawings in greater detail, the hoist
mechanism 8 (FIG. 5) of the present invention finds particular
advantageous use in a collapsible container of the type indicated
at 10 in FIGS. 1 to 4. This container 10 includes end walls 11 and
12 (FIG. 3) pivotally mounted on a base or floor 14 and inwardly
folding sidewalls 15 and 16 (FIG. 4). The sidewalls 15 and 16 are
hingedly connected at the upper edge thereof to a roof panel 18
(FIG. 4). To collapse the container 10, the roof panel 18 is
lowered with the sidewalls 15 and 16 folding inwardly as best shown
in FIG. 4. After the sidewalls 15 and 16 of the container 10 have
been folded inwardly with the roof panel 18 lowered on top of the
folded sidewalls 15 and 16, the end walls 11 and 12 of the
container are pivoted inwardly and downwardly over the roof pane 18
to a collapsed position shown in FIG. 3. One of the end walls 11
has door panel sections 20 and 22 which are hingedly connected to
corner posts 26 and 28 of the end wall 11 and the other end wall 12
has a single end panel 31 secured between corner posts 32 and 34 of
the end wall 12. Each of the corner posts 26, 28, 32 and 34 is
pivotally connected at the lower end thereof to a corner of the
base 14 such as the lower end 36 of the corner post 26 is pivotally
connected to the corner 38 of the base 14. As best shown in FIG. 4,
the corner posts 26, 28, 32 and 34 form upstanding supports for the
roof 18 and the sidewalls 15 and 16. It will be understood, that
although not shown, suitable latches and keepers are provided for
releasably securing the roof panel 18 to the upper beams 39 and 40
of the end walls 11 and 12.
Referring now to FIG. 5, the hoist mechanism 8 includes four cables
41-44 of each of which is anchored at one end to one of four
winches 45-48 mounted in the base 14. A portion of each cable 41-44
is coiled on one of the winches 46-48 and the remaining portion of
each cable is directed over one of four cable tensioning devices 49
and one of four guide pulleys 50, to one of the corner posts 26,
28, 32 or 34 where it is trained over lower and upper guide rollers
or pulleys 51 and 52 (FIG. 2) to the upper end 53-56 of each corner
post 26, 28, 32 and 34. The other end of each cable 41-44 extends
from the upper end 53-56 of one of the corner posts 26, 28, 32 or
34 for connection to the roof panel 18 at spaced apart locations
thereon. These locations are essentially at the four corners 57-60
(FIG. 4) of the roof panel 18.
The four winches 45-48 are driven by a common drive shaft 61 which
is rotatably mounted on the base 14 and extends across the base 14
generally parallel to the pivot axis of the end walls 11 and 12.
The drive shaft 61 has drive sockets 62 and 63 at either end
thereof which are adapted to receive a mating projection of a
suitable rotary power device (not shown) such as an electric motor.
The drive connection from each of the winches 45-48 to the drive
shaft 61 includes a gear box 66-69 connected to each winch 45-48, a
first shaft portion 71-74 connecting each gear box to one side of a
slip clutch 76-79, a second shaft portion 81-84 connecting the
other side of each slip clutch 76-79 to a first sprocket 86-89, and
a chain 91-94 connecting each sprocket 86-89 to a second sprocket
96-99 mounted on the drive shaft 61.
As best shown in FIG. 6, each of the cable tensioning devices 49
includes a spring 106 which is secured at one end 108 to a frame
member 110 which forms part of the base 14 and which is positioned
in the center thereof extending parallel to the sidewalls 15 and
16. The other end 112 of the spring 106 is connected to a sheave
assembly 113 which includes a pulley block 114 connected at one end
115 to the spring 106 and at the other end 117 to a pulley 118. One
of the cables, in this instance cable 44, is trained over the
pulley 118. A U-shaped bracket 120 forming a guideway for the
spring 106 and the end 115 of the pulley block 116 has two leg
portions 121 and 122 which are secured by suitable fasteners 123 to
the frame member 110 and a bight portion 124 which forms a stop for
the end 115 of the pulley block 116.
Although FIG. 4 shows the cables 41-44 connected to the roof panel
18 at the upper edge thereof, it is preferred that the cables 41-44
be connected to the roof panel 18 at a point below the plane of the
roof panel 18. For this purpose, the cables 41-44 are each
connected to a lug on a flange 124 which is secured to the roof
panel 18 and which extends downwardly therefrom parallel to the
sidewalls 15 and 16 as best shown in FIGS. 1-3. In this way, when
the roof panel 18 is raised to its fully raised position, the
portion of the cable 41 extending from the upper end 53 of the
corner post 26 will be extending downwardly at a significant angle
with respect to the horizontal. It will be appreciated that if the
roof panel 18 was not secured to the cables in this manner and a
small angle existed between the cables 41-44 and the horizontal
when the roof panel 18 was in its fully raised position, a large
tension force would be required on the cable to provide the
vertical force needed for holding the roof panel in the raised
position prior to the latching of the roof panel 18 to the end
walls 11 and 12.
To ensure that the flanges 124 do not adversely affect the nesting
position of the end walls 11 and 12 over the roof panel 18 and the
base 14 when the container 10 is in the collapsed condition, the
base 14 is provided with recessed portions 125 near each corner of
the base 14 in the area below the ends of each of the sidewalls 15
and 16. These recessed portions 125 are of a similar configuration
as the flanges 124 so that each flange 124 can be received in the
space formed by each recessed portion 125.
Also, to prevent the cables 41-44 from extending along the sides of
the base 14 and then upwardly over the side edges of the base 14
and under the corner posts such as the corner 26, a guide lug
portion 126 is provided on the base 14 adjacent each of recessed
portions 125 for guidingly receiving respective ones of the cables
41-44. In this way, the cables 41-44 are kept out of the "way" when
the end walls 11 and 12 are folded over the base 14 as shown by the
position of the cable 41 in FIG. 3.
In the operation of the hoist mechanism 8 for raising the roof
panel 18, it will be appreciated that it is desirable to have each
of the cables 41-44 shorten its length uniformly so that the roof
panel 18 will remain horizontal as it is raised and also so that
the corners 57-60 of the roof panel 18 will reach their upward
limit of travel at approximately the same time. To raise the roof
panel 18 and shorten the lengths of the cables 41-44 uniformly, the
four winches 45-48 are driven in synchronized relationship by the
drive shaft 61. However, even with the synchronous drive, the
cables 41-44 may not be uniformly shortened since each of the
cables is not necessarily wrapped uniformly on its associated winch
45-48 due to the tendency of the winches 45-48 to scramble wind the
associated cable 41-44 instead of winding the cable 41-44 in a
spiral wrap, layer by layer. Also, because of the tolerances in the
various parts of the hoist mechanism 8 and the container 10 and
because of the uneven stretching or shrinking of the cables 41-44
after the container 10 has stood in an erected or collapsed
condition for a period of time, the respective lengths of each of
the cables 41-44 extending from each of the winches 45-48 to a
corner 57-60 of the roof panel 18 will vary.
To compensate for differences in the lengths of the portion of each
cable 41-44 extending from each winch 45-48 to each corner 57-60,
each winch for the slip clutch 76-79 associated therewith. Although
the clutch 76-79 are shown in the drive connections between the
drive shaft 61 and the winches 45-48, it is to be understood that
they can be situated in the drums of the winches 45-48. These
clutches 76-79 compensate for the differences in the cable lengths
by slipping when the corner 57-60 of the roof panel 18 has reached
its upward limit of travel before the other corners, the tension on
the cable 41-44 connected to that corner 57-60 will be increased by
the torque placed on the associated winch 45-48 until a
predetermined torque (relative to the maximum tension allowable on
the cables 41-44) is reached where the slip clutch 76-79 will slip.
In this way, continued rotation of the power drive shaft 61 to
complete the raising of the other corners 57-60 to their upward
limit of travel will not cause damage to the cables 41-44 connected
to the corners 57-60 which have already reached their upward limit
of travel or to any other part of the hoist mechanism 8.
Accordingly, the slip clutches 76-79, prevent damage to the hoist
mechanism 8, align the roof panel 18 when it is raised to its fully
raised position, ensures that the corners 57-60 are raised to their
upward limits of travel, maintains the corners 57-60 at these upper
limits and ensures that the portion of each cable 41-44 extending
from each winch 45-48 will be shortened to its minimum length
regardless of the way in which it was wrapped on the winch 45-48 to
which it is connected.
It will be understood that all the winches 45-48 are usually over
wound to the point where the slip clutches 76-79 slip to ensure
that each corner 57-60 is raised to its upward limit of travel.
When this is done the spring 106 of each of the sheave assemblies
114 is fully extended to the stop 123, it being understood that the
tension placed on the cables 41-44 by each of the cable tensioning
devices 49 is less than the tension necessary to cause the slip
clutches 76-79 slip. In this way, the cable tensioning devices 49
are in a position to take up slack such as when the upper and lower
sections of the sidewalls 15 and 16 (FIGS. 1 and 2) are pulled
outwardly to place these sections in a vertical upright position
and when the corners 57-60 are locked in place. It will be
understood that with each cable 41-44 having its own cable
tensioning device 49 the corners 57-60 of the roof panel 118 may be
locked one at a time or simultaneously without causing slack in any
one of the cables 41-44. Also, it will be understood that when the
sections of the sidewalls 15 and 16 are pulled outwardly to place
them in a vertical upright position the middle portion of one or
both of the sidewalls 15 and 16 may be pulled "overcenter" past the
vertical position such that the upper and lower sections of the end
walls 15 and 16 are inclined outwardly. If this should occur, the
cable tensioning devices 49 will compensate for the slack by
movement of the spring 106 in the guideway 120.
The cable tensioning devices are provided for preventing slack from
developing in any of the cables at any position of the roof panel
118. In particular, the cable tensioning devices 49 "pickup" slack
when the roof panel 118 is lowered to its lowermost position. Thus,
if the cables 41-44 are unwound unevenly so that one of the corners
57-60 reaches its lowermost position before the other corners, the
cable tensioning device 49 associated with the cable 41-44
connected to the corner 57-60 will "pickup" the slack. Of course it
is to be understood that when the roof panel 18 is being lowered,
the tension on the cables 41-48 is related to the weight of the
roof panel 118 supported by the cables 41-44. Thus, on the
unwinding of the cables 41-44 from the winches 45-48 to lower the
roof panel 118 to its lowermost position, the spring tensioning
devices 49 will pick up some of the slack when one or more of the
winches unwinds more cable than the other winches. However, it will
be understood that the cable tensioning devices 49 cannot
compensate for all the slack developed on continued unwinding of
cable from the winches after all of the corners 57-60 have reached
their lower limit of travel.
Thus, the cable tensioning devices 49 serve to pick up slack when
the roof panel 118 is lowered to its lowermost position so that
loose cables in the base 14 will be prevented, and when the roof
panel 118 is raised to its uppermost position and then locked in
place, and, as will be more fully described in connection with the
description of FIGS. 7 and 8, the cable tensioning devices 49 serve
to pickup slack caused by the folding of the end walls 11 and 12
over the roof 18. Also, it is to be understood that the cable
tensioning devices 49 can take other forms and can be located in
other positions. For example, the cable tensioning devices can take
the form of a spring and stop mechanism mounted in the drum of each
winch for maintaining tension on the cables 41-48.
As indicated in FIG. 7, when the corner post 26 is in a vertical
position, the length of the cable 41 extending from the guide
roller 52 to the corner 57 of the roof panel 118 will be equal to
L.sub.1. However, as the corner post 26 is lowered about its pivot
axis as indicated in FIG. 8, the length L.sub.2 of the cable 41
from the pulley 52 to the corner 57 will not necessarily be equal
to the length L.sub.1. In some cases it will be more and in other
cases it will be less. However, neither excess tension or slack
will be developed in the cable 41 since the spring 106 of the cable
tensioning device 49 associated with the cable 41 will move
outwardly or inwardly to compensate for the increase or decrease in
tension on the cable 41. It will be understood that an increase or
decrease in tension in the other cables 41-44 when the other posts
28, 32 and 34 are lowered will be "picked up" by the cable
tensioning devices 49 in like manner.
Although the hoist mechanism 8 of the present invention has been
described with particular reference to its use in a collapsible
container it is to be understood that the hoist mechanism 8 may
find advantageous use in other applications where it is necessary
to periodically move a horizontal panel between a fully lowered
position and a fully raised position and where it is desirable to
have a hoist mechanism which will maintain the panel essentially
horizontal during the raising and lowering thereof by reason of
devices which will automatically compensate for stretching or
shrinking of the cables and for unequal winding of the cables on
the winches of the hoist mechanism. Moreover, although the hoist
mechanism 8 has been described with reference to pivotable
upstanding supports 26, 28, 32 and 34, it is to be understood that
it can be used with a frame structure having rigid upstanding
supports.
* * * * *