Implements or apparatus for applying pushing or pulling force – Single throw lever – Special engaging feature
Reexamination Certificate
2002-09-30
2003-12-16
Watson, Robert C. (Department: 3723)
Implements or apparatus for applying pushing or pulling force
Single throw lever
Special engaging feature
Reexamination Certificate
active
06663085
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention pertains to a portable lifting device. More particularly, this invention pertains to a device having a base and articulated arms for lifting and moving items with minimal effort by an operator.
2. Description of the Related Art
The standard shovel, spade, and snow scoop requires both hands of the operator and places great stress on the back of the operator. Various means for aiding the operator have been invented to ease the burden placed on the operator during lifting. These means include adding lever arms to the shaft and changing the shape of the shaft.
U.S. Pat. No. 2,419,015, issued to Gascoigne, et al., on Apr. 15, 1947, titled “Agricultural Implement,” discloses a digging implement, such as a spade or fork, having a spring-loaded attachment that comes into contact with the surface after the implement is inserted into the ground. The implement has a shaft A
1
with a tool head A at one end and an extension handle A
3
at the other end. The extension handle A
3
is desirable because of the automatic action produced by the spring D.
Once the implement is in the ground, the attachment serves as a spring-loaded lever, allowing the implement to lift a quantity of soil. The attachment is fixed to the implement shaft A
1
with an eye B
x
engaging an eye A
5
on a collar A
4
fixed to the shaft A
1
, which allows the implement shaft A
1
to tilt relative to the attachment and to rotate relative to the attachment. The lever action is due to the tilting allowed by the eye-in-an-eye assembly A
5
-B
x
, and it is assisted by the spring D, which adds a lifting force to the tool head A. A chain E is provided to limit the action of the spring D on the attachment. The raised soil load is dumped by swinging the implement shaft A
1
laterally and then rotating the shaft A
1
, allowing the soil to slide off the tool head A. The Gascoigne, et al., tool has the disadvantage of not providing a stable connection at the shaft A
1
due to the inherent nature of the eye-in-an-eye assembly A
5
-B
x
.
Over the years following the issuing of the Gascoigne, et al., patent, various other patents have issued for digging tools with some form of lifting aid. A representative sampling includes the following. U.S. Pat. No. 4,461,458, issued to Poulin on Jul. 24, 1984, titled “Low Effort Digging and Lifting Tool,” discloses a lever arm
28
pivotally connected to a shovel head
25
with a pivot
24
. The lever arm
28
is pivotally connected to a foot plate
33
having a cleat
34
.
U.S. Pat. No. 4,722,512, issued to Lighthizer on Feb. 2, 1988, titled “Hand Operated Digging Tool Comprising a Ground Penetrating Portion,” discloses a lever arm
12
hingedly attached to the back of the shovel
10
adjacent to where the shovel
10
engages its handle
11
. The lever arm
12
assumes a desired approximately 45° angle with the back of the shovel
10
because of the positioning of the extension
14
, which projects from the lever arm
12
and contacts the back of the shovel
10
. In operation, the lever arm
12
is held against the shovel handle
11
by a magnet
15
. The lever arm
12
is released from the magnet
15
when the shovel
10
strikes the soil, as in digging, and the arm
12
is captured by the magnet
15
when the shovel is levered such that the shovel handle
11
is positioned parallel to the ground.
U.S. Pat. No. 4,881,332, issued to Evertsen on Nov. 21, 1989, titled “Shovel Lifting Aid,” discloses another variation of a lifting lever
16
attached to a handle
11
of a shovel
12
. The lifting lever
16
is attached to the shovel handle
11
by a pivot handle attachment mechanism
17
. The mechanism
17
includes a sleeve
30
inside a sleeve
26
. The inner sleeve
30
is secured to the handle
11
by a screw clamp
31
,
32
. The screw clamp
32
passes through a slot in the outer sleeve
26
, thereby allowing the outer sleeve
26
to freely rotate about the inner sleeve
30
.
U.S. Pat. No. 6,203,081, issued to Kegan, Sr. on Mar. 20, 2001, titled “Easy Lift Levered Shovel,” discloses a levered fulcrum
18
pivotally attached to the shaft
16
. The movable clamp
22
positions the levered fulcrum
18
at any point on the shaft
16
by way of a nut and bolt arrangement
24
. The levered fulcrum
18
is spring-loaded by a spring
28
to maintain the fulcrum
18
in a nested position. The operator pivots the lever against the resiliency of the spring
28
rearwardly away from the shank
16
such that the fulcrum
18
rests on the ground.
An objective of this invention is to provide a lifting tool that requires minimal effort from the operator, provides a stable platform for the lifted load, and can be operated at a convenient height, minimizing bending by the operator.
It is a further objection of this invention to enable those confined to a wheelchair to lift items that otherwise would not be lifted.
BRIEF SUMMARY OF THE INVENTION
According to one embodiment of the present invention, a portable hand-operating lifting device is provided. The device includes a lifting head, which in one embodiment is a shovel blade, and a lifting shaft having a handle at the end opposite the lifting head. A lever arm is attached between the lifting head and the lifting shaft. The lever arm is pivotably and swivelly connected to a cleated foot plate. The foot plate has a lifting plate, which allows the operator to remove the foot plate from the surface and reposition the foot plate such that the lifting device can be used in a different location.
In one embodiment, the handle is adjustable in that the distance between the handle grip and the lifting head can be extended or shortened. In another embodiment, the angle of the lifting handle relative to the lifting shaft is adjustable. In still another embodiment, the angle of the lifting shaft relative to the lifting head is adjustable.
REFERENCES:
patent: 2419015 (1947-04-01), Gascoigne et al.
patent: 2769612 (1956-11-01), Weisheit
patent: 4461458 (1984-07-01), Poulin
patent: 4722512 (1988-02-01), Lighthizer
patent: 4881332 (1989-11-01), Evertsen
patent: 5120098 (1992-06-01), Childress
patent: 5669651 (1997-09-01), Vroegindewey
patent: 5732933 (1998-03-01), Champi
patent: 5871058 (1999-02-01), Naccarato et al.
patent: 6062619 (2000-05-01), Clark, Jr.
patent: 6086049 (2000-07-01), Shells
patent: 6203081 (2001-03-01), Kegan, Sr.
patent: 6276665 (2001-08-01), Hawkins et al.
Pitts & Brittian P.C.
Watson Robert C.
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