Information
-
Patent Grant
-
6357810
-
Patent Number
6,357,810
-
Date Filed
Friday, January 14, 200024 years ago
-
Date Issued
Tuesday, March 19, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
-
CPC
-
US Classifications
Field of Search
US
- 294 6721
- 294 673
- 294 674
- 294 675
- 294 683
- 294 811
- 294 813
- 294 815
- 294 8155
- 294 8156
-
International Classifications
-
Abstract
A hoist assembly 10 for lifting an object 12 includes a support fixture 14 having three elongated support rails or members 16, 18, and 20, a movable lever assembly 24, which is mounted upon a spanning member 22, and three interconnecting chains, members or assemblies 26, 28, and 30 which are coupled to fixture 14 and to object 12. Movable lever assembly 24 moves from a first position to a second position when object 12 is lifted, thereby shifting the center of gravity 142 of the fixture 14 and allowing fixture 14 and object 12 to remain in a level or horizontal position.
Description
FIELD OF THE INVENTION
The present invention generally relates to a hoist assembly and more particularly, to a hoist assembly including a movable member which selectively and automatically shifts the center of gravity of the hoist assembly, thereby allowing the hoist assembly to remain in a substantially level position when it is loaded and unloaded.
BACKGROUND OF THE INVENTION
Hoist assemblies are generally used to lift, elevate, and/or move relatively heavy and/or cumbersome components, devices, and/or other objects. Hoist assemblies typically include several members which are interconnected to cooperatively form a frame or support fixture, and one or more chains, cables, or other connecting members which are selectively attached to the support fixture and to the device or object that is desired to be lifted. The support fixture is coupled to a motor, winch, or other lifting assembly or apparatus which selectively lifts or elevates the fixture and the object or device which is attached to the fixture. These types of fixtures are typically designed to allow the lifted object or device to remain substantially level (e.g., horizontal) while it is being lifted and/or moved, thereby preventing movable components or movable portions of the object or device from being undesirably moved or displaced while the object is being lifted.
One of the major drawbacks associated with these prior hoist assemblies is that the process of loading and/or unloading devices and other objects to/from these prior hoist assemblies is undesirably time-consuming, difficult, and cannot typically be performed by a single person or operator. For example and without limitation, when used to lift an object which has an “off-centered” center of gravity (e.g., a center of gravity which is located remote from the center of symmetry of the object), the support fixture which is used is typically manufactured or formed to be disproportionately or unevenly “weighted” in order to compensate for the “off-centered” center of gravity of the object, thereby ensuring that the object and fixture remain in a level position when the object or device is lifted. This disproportionate or uneven “weighting” causes the fixture to undesirably reside in an “unleveled” or sloped position when it is not “loaded” (i.e., when the object is not attached to the fixture), and therefore requires the fixture to be “leveled” prior to attaching the object or device to the fixture. Hence, in order to secure and/or remove items to/from these prior hoist assemblies, one individual or operator is required to hold the relatively heavy and cumbersome fixture in a substantially horizontal and/or level position, while another individual or operator connects the object or device to the fixture. Moreover, the relatively heavy weight of the fixture often causes the fixture to slip, drop, or pitch while it is being held, thereby potentially damaging the object or device which is being attached to the fixture.
There is therefore a need for a new and improved hoist assembly which overcomes many, if not all, of the previously delineated drawbacks of such prior hoist assemblies.
SUMMARY OF THE INVENTION
It is therefore a primary object of the invention to provide a hoist assembly which overcomes at least some, if not all, of the previously delineated disadvantages of prior hoist assemblies.
It is a second object of the invention to provide a hoist assembly which includes a support fixture which remains in a substantially level position when it is loaded and unloaded.
It is a third object of the invention to provide a hoist assembly which is further characterized by its ability to allow a single user or operator to relatively easily secure and/or attach an object to the hoist assembly.
It is a fourth object of the invention to provide a hoist assembly for lifting an object which includes a movable member that selectively and automatically shifts the center of gravity of the hoist assembly when the object is lifted, thereby causing the assembly and the object to remain in a substantially level position.
According to one aspect of the present invention, a hoist assembly for lifting an object is provided. The hoist assembly includes a plurality of interconnecting members which are selectively coupled to the object; and a fixture which is coupled to the interconnecting members and which is selectively suspended at a first location. The fixture has a movable member and a center of gravity, the center of gravity being aligned with the first location when the object is not being lifted, thereby allowing the fixture to be suspended in a substantially level position. The movable member is movable from a first position to a second position in response to the object being lifted, the movement being effective to cause the center of gravity to shift to a second location, the shift being effective to cause the fixture and the object to remain level while the object is being lifted.
According to a second aspect of the present invention, a method for lifting an object is provided. The method includes the steps of: providing a fixture having a movable member and a center or gravity; suspending the fixture from a point on the movable member which is substantially aligned with the center of gravity, thereby causing the fixture to remain in a substantially level position; coupling the object to the fixture; providing an upward force at the point, effective to lift the object and to cause the movable member to move, thereby shifting the center of gravity and causing the object to remain in a level position.
Further objects, features, and advantages of the present invention will become apparent from a consideration of the following description and the subjoined claims, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a perspective view of a hoist assembly which is made in accordance with the teachings of the preferred embodiment of the invention, and which is illustrated in an unloaded state;
FIG. 2
is a perspective view of the hoist assembly which is shown in
FIG. 1
, and which is illustrated in a loaded state;
FIG. 3
is a top view of the hoist assembly shown in
FIG. 1
;
FIG. 4
is a partial bottom perspective view of the hoist assembly shown in
FIG. 1
; and
FIG. 5
is a partial cross sectional view of the hoist assembly shown in FIG.
1
and taken along view lines
5
—
5
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
Referring now to
FIGS. 1-5
, there is shown a hoist apparatus or assembly
10
which is made in accordance with the teachings of the preferred embodiment of the invention, and which is adapted to operatively lift an object
12
having an “off-centered” center of gravity
13
(e.g., a center of gravity which is located remote from the center of symmetry
11
of object
12
). As shown, assembly
10
includes a support fixture
14
having three elongated support rails or members
16
,
18
, and
20
, a movable lever assembly
24
, which is mounted upon a spanning member
22
, and three interconnecting chains, members or assemblies
26
,
28
, and
30
which are selectively coupled to fixture
14
and to object
12
. Fixture
14
is removably coupled to a force-providing or lifting member or assembly
32
by use of an interconnecting chain, member or assembly
34
. Assembly
32
selectively provides an upward force in the direction of arrow
42
, which is effective to lift fixture
14
and object
12
.
Elongated rail members
16
,
18
, and
20
are manufactured and/or formed from a relatively strong and durable conventional and commercially available material such as steel, aluminum or any other suitable material, and each include a plurality of substantially identical apertures
44
. Members
16
,
18
, and
20
have substantially identical and generally “C”-shaped cross-sections that respectively form slots or channels
46
,
48
, and
50
which are substantially, respectively and longitudinally coextensive with rail members
16
,
18
, and
20
.
In the preferred embodiment, members
16
-
20
cooperatively form a generally triangular frame or structure, and are fixedly coupled together by way of three substantially identical plate members
36
,
38
, and
40
. Particularly, plate member
36
is fixedly coupled to members
16
and
20
by way of a pair of substantially identical and conventional bolt-type fasteners
52
, each of which conventionally, respectively and operatively engage a unique one of apertures
44
formed within member
16
and member
20
, thereby operatively connecting members
16
and
20
. Plate member
38
is fixedly coupled to members
16
and
18
by way of a pair of fasteners
52
, each of which conventionally, respectively and operatively engage a unique one of apertures
44
formed within members
16
and
18
, thereby operatively connecting members
16
and
18
. Plate member
40
is fixedly coupled to members
18
and
20
by way of a pair of fasteners
52
, each of which conventionally, respectively and operatively engage a unique one of apertures
44
formed within members
18
and
20
, thereby operatively connecting members
18
and
20
.
In other alternate embodiments, plate members
36
-
40
are coupled to members
16
-
20
in other conventional manners such as by clamps, screws, adhesives, and/or any other suitable fastening devices or methods. In one non-limiting embodiment, members
16
-
20
are directly and physically coupled together in a conventional manner such as by welding, sintering, bonding or any other suitable manner or device.
Spanning member
22
is removably and/or adjustably coupled to rails
16
and
20
in a conventional manner. In the preferred embodiment of the invention, as best shown in
FIG. 5
, spanning member
22
includes two substantially identical generally “T”-shaped clamping portions or members
72
which insertably, conformingly, and respectively reside within channel
46
of member
16
and within channel
50
of member
20
. Each member
72
includes a centrally disposed and threaded aperture
74
which selectively and operatively receives a conventional bolt-type fastener
76
, thereby selectively and clampingly securing spanning member
22
to rails
16
and
20
. It should be appreciated that fasteners
76
may be loosened, effective to allow members
72
to slidably move within channels
46
and
50
, thereby allowing the position of spanning member
22
to be selectively adjusted.
As best shown in
FIG. 4
, movable lever assembly includes a generally “L”-shaped lever or arm member
54
and a movable rod member
60
. Member
54
is conventionally and pivotally mounted to a pair of substantially identical and generally rectangular support members
66
,
68
which are fixedly and conventionally mounted to the top surface
84
of spanning member
22
by use of conventional bolt-type fasteners
78
. In the preferred embodiment of the invention, lever or arm member
54
is pivotally coupled to support members
66
,
68
by way of a conventional pin, rod, or dowel member
70
, thereby allowing member
54
to be pivotally movable in the directions illustrated by arrows
80
and
82
. In the preferred embodiment of the invention, member
70
includes a bearing or bushing (not shown) which rotatably engages member
54
.
Lever or arm member
54
includes an “upper” end
56
, which is selectively coupled to interconnecting member
34
, and a “lower” end
58
, which is coupled to movable rod member
60
. End
56
includes a generally oval-shaped linking or connecting member
61
which is pivotally and conventionally coupled to end
56
by way of a conventional rod, pin, or dowel member
62
and which selectively couples end
56
to member
34
. End
58
of lever or arm member
54
is conventionally and pivotally coupled to rod member
60
by way of a conventional rod, pin, or dowel member
64
.
Rod member
60
includes a generally cylindrical spring-engaging member or portion
88
, which engages a selectively compressible and expandable spring member
90
, and a narrow portion
92
, which slidably engages a generally square support member
94
. Portion
88
of rod
60
includes a channel
96
in which a portion of spring
90
operatively resides. Channel
96
terminates in an end
98
, which abuttingly engages end
100
of spring
90
.
In the preferred embodiment, spring
90
is a conventional and commercially available coil-type spring. In other alternate embodiments, spring
90
may comprise a gas spring or another type of spring device. Spring
90
is operatively disposed around portion
92
of rod
60
, and includes a second end
102
, which abuttingly engages member
94
.
Member
94
includes a generally cylindrical shaped channel
104
within which portion
92
is slidably disposed. Member
94
is conventionally and pivotally coupled to a pair of substantially identical and generally rectangular support members
106
,
108
that are fixedly and conventionally mounted to the bottom surface
86
of spanning member
22
by use of conventional bolt-type fasteners
110
. In the preferred embodiment, member
94
is pivotally coupled to support members
106
,
108
by way of a conventional pin, rod, or dowel member
112
, and is pivotally movable in the directions which are illustrated by arrows
114
. Portion
92
includes a threaded end portion
116
on which nuts or weighted members
118
may be selectively attached.
It should be appreciated that the movement of lever or arm member
54
, in the direction of arrow
80
, will cause spring
90
to be compressed and rod
60
to move in the direction illustrated by arrow
120
. Furthermore, the movement of lever or arm member
54
in the direction of arrow
82
will cause spring
90
to expand and rod
60
to move in the direction illustrated by arrow
122
.
In the preferred embodiment of the invention, interconnecting members or assemblies
26
-
30
comprise conventional chains. In other alternate embodiments, assemblies
26
-
30
may comprise cables, cords, ropes, or any other suitable interconnecting members or assemblies. Interconnecting assemblies
26
,
28
, and
30
are respectively coupled to plate members
36
,
38
, and
40
by way of conventional and substantially identical eyebolts
124
. Assemblies
26
-
30
further include substantially identical conventional hook or “latch”-type fasteners or fastening members
126
. In alternate embodiments, fasteners
126
may comprise a variety of other known attachment or fastening devices or apparatuses. Fasteners
126
are adapted to selectively and conventionally engage eyebolts
128
, which are fixedly coupled to object
12
.
Force-providing or lifting assembly
32
comprises a conventional winch, pulley system, crane, motor, or other assembly, which is effective to selectively pull and/or draw interconnecting member
34
in the direction of arrow
42
, thereby lifting and/or elevating fixture
14
and object
12
. In the preferred embodiment of the invention, assembly
32
includes a conventional remotely-operated, hand-held controller
35
which electrically and communicatively coupled to assembly
32
by way of a conventional communications cable or wire
37
, and is effective to selectively activate, position, and/or move assembly
32
and member
34
. A conventional hook or latch type member
136
selectively receives connecting member
61
, thereby securing fixture
14
to assembly
32
.
In operation, fixture
14
is coupled to assembly
32
. Particularly, connecting member
61
is operatively inserted into and received by latch member
136
. When connected to latch
136
, fixture
14
is suspended in a substantially level or horizontal position (i.e., in a position substantially parallel to ground surface
138
). This substantially level “suspension” of fixture
14
is achieved by suspending the fixture
14
from a point or location
140
which is substantially aligned with the center of gravity
142
of fixture
14
. Particularly, location
140
and center of gravity
142
both substantially lie along a substantially vertical axis
144
. The substantially level or horizontal suspension of fixture
14
allows a single user to operatively position the fixture
14
over object
12
by way of controller
35
.
Once fixture
14
is substantially and operatively aligned with object
12
, a user or operator lowers fixture
14
and attaches hook or latch members
126
to eyebolts
128
, as shown in FIG.
2
. Assembly
32
is then activated and provides a lifting or elevating force in the direction of arrow
42
. This force is transferred to arm or lever member
54
by way of connector member
61
, and cooperates with the weight of object
12
to cause member
54
to pivot in the direction illustrated by arrow
80
. As member
54
pivotally moves in the direction of arrow
80
, rod
60
moves in the direction of arrow
120
, thereby compressing spring
90
. Once the force required to further compress spring
90
exceeds the weight of object
12
and fixture
14
, the object
12
is lifted or elevated from surface
138
.
The movement and weight of arm or lever member
54
causes the center of gravity
142
of fixture
14
to move or shift to a new point or location
146
which is substantially aligned with the center of gravity
13
of object
12
. Additionally, this shifting movement of lever member
54
further causes the point or location
140
at which the lifting force of assembly
32
is provided to become substantially aligned with the center of gravity
13
of object
12
. Particularly, location
140
, the new center of gravity
146
of fixture
14
, and the center of gravity
13
of object
12
each substantially lie along a substantially vertical axis
150
. It should be appreciated that in this manner, both object
12
and fixture
14
remain in a substantially level or horizontal position when object
12
is lifted (i.e., both object
12
and fixture
14
remain substantially parallel with respect to the ground surface
138
). When object
12
is disconnected or removed from hoist assembly
10
, arm or lever
54
pivotally moves in the direction illustrated by arrow
82
, and returns to its original or “unloaded” position, thereby shifting the center of gravity
142
to its original location and substantially leveling the fixture
14
.
It should be appreciated that by adjusting the force required to compress spring
90
(e.g., by adjusting the spring constant “k” of spring
90
) the center of gravity
142
of fixture
14
can be made to shift by different amounts and to different locations, thereby allowing hoist assembly
10
to be relatively easily adapted to lift different types of objects and devices having different centers of gravity. Additionally, spanning member
22
may be adjustably moved, and/or additional weighted members
118
may be selectively attached to and/or removed from portion
116
of rod
60
, in order to change or alter the center of gravity of fixture
14
, thereby accommodating different types of objects and devices.
It should be understood that this invention is not limited to the exact construction or embodiments listed and described but that various changes may be made without departing from the spirit and scope of the invention.
Claims
- 1. A hoist assembly for lifting an object, said hoist assembly comprising:a plurality of interconnecting members which are selectively coupled to said object; and a fixture which is coupled to said interconnecting members and which includes a movable member from which said fixture is selectively suspended and a center of gravity, said center of gravity being located in a first location which allows said fixture to be suspended in a substantially level position when said object is disconnected from said fixture, said movable member being automatically and pivotably movable without operator assistance from a first position to a second position in response to said object being lifted, said movement being effective to cause said center of gravity to shift to a second location, said shift being effective to cause said fixture and said object to remain level while said object is being lifted.
- 2. The hoist assembly of claim 1 wherein said fixture is generally triangular in shape.
- 3. The hoist assembly of claim 2 wherein said fixture comprises three elongated members.
- 4. The hoist assembly of claim 3 wherein said three elongated members are interconnected by three plate members.
- 5. The hoist assembly of claim 4 wherein said plurality of interconnecting members comprise three chains, each of said three chains being coupled to a unique one of said plate members.
- 6. The hoist assembly of claim 1 further comprising a selectively compressible spring which is coupled to said movable member, said spring being compressed when said movable member moves from said first position to said second position.
- 7. The hoist assembly of claim 1 wherein said movable member comprises a generally “L”-shaped arm member.
- 8. The hoist assembly of claim 1 further comprising a spanning member which is removably mounted upon said fixture, and on which said movable member is pivotally disposed.
- 9. The assembly of claim 1 wherein said object has a center of gravity which is disposed in a third location and wherein said second location is substantially aligned with said third location.
- 10. A hoist for lifting an object having a first center of gravity, said hoist comprising:a force providing member which selectively provides an upward lifting force; a generally triangular support member having a second center of gravity; a plurality of interconnecting assemblies, which selectively couple said support member to said object; and a movable lever assembly which is fixedly coupled to said triangular support member, and which is selectively coupled to said force providing member, said movable lever assembly is movable from a first position to a second position when said object is lifted, said movement being effective to cause said second center of gravity to be substantially aligned with said force providing member when said movable lever assembly is in said first position, thereby allowing said support member to be suspended in a substantially level position, and to cause said second center of gravity to be aligned with said first center of gravity when said movable lever assembly is in said second position, thereby ensuring that said object remains level while said object is being lifted.
- 11. The hoist of claim 10 wherein said generally triangular support member comprises three interconnected elongated rail members.
- 12. The hoist of claim 10 further comprising a spanning member on which said movable member is disposed, said spanning member being selectively and removably attachable to said support member in a plurality of positions.
- 13. The hoist of claim 12 further comprising a selectively compressible spring member which is operatively coupled to said movable lever assembly and to said spanning member, said spring member being compressed when said movable lever assembly is moved from said first to said second position.
- 14. The hoist of claim 10 wherein said movable lever assembly comprises a generally “L”-shaped lever.
- 15. A method for lifting an object, said method comprising the steps of:providing a fixture having a movable member and a center of gravity; suspending said fixture from a point on said movable member which is substantially aligned with said center of gravity, thereby causing said fixture to remain in a substantially level position while said fixture is suspended; providing at least one linking member; coupling said at least one linking member to said fixture; coupling said at least one linking member to said object, thereby connecting said object to said fixture; providing an upward force at said point, effective to lift said object, and to cause said movable member to move, thereby shifting said center of gravity and causing said object and said fixture to remain in a level position; wherein said fixture comprises three elongated and interconnected rail members; and wherein said at least one linking member comprises three separate linking members.
- 16. The method of claim 15 wherein said three linking members each comprises a latch.
- 17. The method of claim 16 wherein each of said three linking members is coupled to said object by way of said latches and three eyebolts which are connected to said object.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
992-383 |
Feb 1983 |
SU |