Abstract:
An apparatus for lifting, having a lever arm attached to a plate that can be temporarily fixed by an operator, and having a lifting head that can be swiveled and rotated relative to the plate. The lifting device includes a lifting head and a lifting arm having a handle at the end opposite the lifting head. A lever arm is attached between the lifting head and the lifting arm. The lever arm is pivotably and swivelly connected to a cleated foot plate. 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 arm is adjustable.

Description:
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. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The above-mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which: 
     FIG. 1 is a perspective view of a lifting device; 
     FIG. 2 shows the lifting device in operation; 
     FIG. 3 a  is a cross-sectional view showing the lever arm attachment to the lifting head shaft; 
     FIG. 3 b  is a cross-sectional view showing the pin through the lifting head shaft; 
     FIG. 3 c  is a perspective view of pin through the lifting head shaft; 
     FIG. 4 is a perspective view of the lifting shaft and adjustable handle connection; 
     FIG. 5 is a perspective view of a foot plate showing the pivot and swivel attachment to the plate; and 
     FIG. 6 is a perspective view of lifting shaft and lever arm connections to the lifting head shaft. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A portable hand-operating lifting device  10  is disclosed. FIG. 1 illustrates a general perspective view of the lifting device  10 , which includes a lifting head  102  with a lifting head shaft, or first member,  104  to which is attached a lever arm, or second member,  112 , and a lifting arm, or third member,  106 . The lifting arm  106  is attached to an adjustable handle  108 . The handle  108  has a first hand grip  118 A and the illustrated embodiment shows a second hand grip  118 B extending from the first hand grip  118 A such that an operator  210  can use two hands to grip the handle  108 . The lever arm  112  is attached to a foot plate  116 . 
     FIG. 2 illustrates the lifting device  10  in operation as a digging tool. The operator  210  places a foot on the foot plate  116  and grasps the lifting handle  108 . The lifting head  102  is positioned by the operator  210  grasping the hand grip  118  and manipulating the lifting handle  108 . In the illustrated embodiment, the lifting head  102  is used to dig soil and deposit it to the side of the dug hole. The lifting head  102  is a shovel head and the operator  210  forces the head  102  into the ground by moving the handle  108  such that the head  102  is in contact with the ground and by pulling on the handle  108 , using the operator&#39;s  210  bodyweight, thereby forcing the head  102  into the ground. The operator  210  then swings the handle  108  about the lever arm pivot point  514  (illustrated on FIG. 5) such that the head  102  follows an arc and lifts a quantity of soil away from the ground. The operator  210  swivels the device  10  with the load of soil about the swivel  512  on the foot plate  116 . When the head  102  is positioned where the soil needs to be deposited, the operator  210  rotates the handle  108  about the axis of the shaft  104 , thereby tilting the head  102  and letting the soil slide off the head  102 . When the device  10  needs to be repositioned, the foot plate  116  is lifted from the surface by the operator  210  sliding his foot forward, placing his toes under the lift plate  232 , and raising his foot, thereby lifting the foot plate  116 . The foot plate  116  and cleat  202  comes free from the surface and is placed at the next location for digging. 
     In the illustrated embodiment, the lifting device  10  is a digging tool that requires no lifting by the operator  210 . The illustrated embodiment is useful for digging sod, in addition to digging holes in the ground. The operator  210  stands on the foot plate  116  and positions the tip of the lifting head  102  such that the lifting head  102  and shaft  104  are almost vertical. If the ground is hard or tightly compacted, the operator  210  can step on the shovel head  102  in order to have the lifting head  102  “bite” into the ground. After the head  102  is positioned, the operator  210  pulls the handle  108  back and down. The head  102  will then enter the ground and follow a curved path, thereby digging up a spadefull of earth. After the lifting head  102  is loaded, the operator  210  pushes down and pulls back on the handle  108  to lift the head  102 . The operator  210  pushes the handle  108  to one side or the other to position the head  102  for releasing the load of earth. After the head  102  is positioned, the operator  210  twists the handle  108 , causing the head  102  to rotate and the earth to slide off the head  102 . 
     Although the illustrated embodiment shows the device  10  as a digging tool, other uses of the device include lifting items on a floor and relocating the items. Those skilled in the art will recognize that the lifting head  102  can be a fork or a flat plate without departing from the spirit and scope of the present invention. The illustrated embodiment includes an adjustable lifting member  106  and an adjustable handle  108 . The length and angle of the lifting member  106  and the handle  108  can be independently adjusted, thereby allowing the device  10  to be operated by persons of various heights. For example, by shortening the member and the handle and by reducing the angle to a minimum, the device  10  is suitable for use by an operator  210  confined to a wheelchair. 
     FIG. 3 a  illustrates a cross-sectional view of the means for attaching the lever arm  112  to the lifting head shaft  104 . The joint includes an opening  304  in the lifting head shaft  104  that permits a pivot pin  302  to move within the shaft  104 . The opening  304 , in one embodiment, is formed by drilling two holes, perpendicular to each other and to the shaft  104  axis, with the holes crossing at the center of the shaft  104 . The material of the shaft  104  between the two holes is removed such that the pin  302 , when inserted into the opening  304 , can be rotated 90° about the axis of the shaft  104 . This amount of rotation allows the lifting head  102  to be rotated from a horizontal position to a vertical position, thereby ensuring that anything supported by the head  102  will slide off when the head  102  is rotated. Those skilled in the art will recognize that the angle about the axis that the pin  302  rotates can vary without departing from the scope or spirit of the present invention. The angle must be less than 180° in order for some material to remain connecting the shaft  104  across the opening  304 . The material remaining serves as stops  622 ,  324  for the pin  302  and provides structural strength to the shaft  104 . In another embodiment, a sleeve (not illustrated) surrounding the shaft  104  has a pair of slotted openings corresponding to the opening  304  in the shaft  104  and provides additional strength to the shaft  104  in the area of the opening  304 . 
     In the illustrated embodiment, the lever arm  112  is made up of a pair of side tube members  112 A,  112 B. In another embodiment, the lever arm  112  has a fork shape with the pair of side members  112 A,  112 B merging into a single member extending to the foot plate  116 . The pivot pin  302  passes through aligned openings in the tube members  112 A,  112 B, which are located on opposite sides of the lifting shaft  104 . Washers  312 A,  312 B are positioned between the shaft  104  and each of the tube members  112 A,  112 B and provide bearing surfaces between the shaft  104  and the tube members  112 A,  112 B. The pivot pin  302  is secured in place by cotter pins  316 A,  316 B (illustrated in FIG.  6 ), each inserted in an opening  306 A,  306 B at each end of the pin  302 . Those skilled in the art will recognize that other means known in the art for securing an axel can be used without departing from the spirit and scope of the present invention. 
     FIG. 3 b  is a side-section view of the pivot pin  302  residing in the opening  304  in the lifting head shaft  104 . The opening  304  is bounded by a pair of flat, parallel surfaces perpendicular to the axis of the shaft  104  and by two stops  322 ,  324 , which limit the rotation of the pivot pin  302  about the axis of the shaft  104 . The opening  304 , bounded by the stops  322 ,  324 , has two slotted apertures along a circumference of the shaft  104 . The pin  302  extends out of the two slotted apertures on opposite sides of the shaft  104 . In the illustrated embodiment, the surfaces of the opening  304  are flat. In another embodiment, the surfaces parallel to the axis of the shaft  104  are rounded. 
     FIG. 3 c  is a perspective view of the pivot pin  302  residing in the opening  304  in the lifting head shaft  104 . The pivot pin  302  is free to rotate axially within the opening  304 . The shaft  104  is free to rotate axially about the pivot pin  302 ; however, the shaft  104  is limited in its rotation by the stops  322 ,  324 . 
     FIG. 4 illustrates the handle  108  attachment to the lifting arm, or member,  106 , which is made up of a pair of tube members  106 A,  106 B. A first pin  402  secures the handle  108  to the lifting arm  106 , and a second pin  412  is a stop to prevent the handle  108  from rotating beyond a certain point about the first pin  402  when the handle  108  is pushed down by the operator. In the illustrated embodiment, the handle  108  is adjustable. In another embodiment, the lifting arm  106  and the handle  108  are fixed relative to each other. 
     The lifting members  106 A,  106 B have aligned openings  404 A,  404 C (plus the openings through which pins  402 ,  412  are positioned), which allow the angle between the lifting member  106  and the handle  108  to be adjusted and also allow the combined length of the lifting member  106  and the handle  108  to be adjusted. In the illustrated embodiment, the pins  402 ,  412  are secured with cotter pins, although one skilled in the art will recognize that any of various means can be used to secure the pins  402 ,  412  in place. 
     FIG. 4 also illustrates the hand grips  118 A,  118 B on the handle  108 . In the illustrated embodiment, two hand grips  118 A,  118 B are shown, allowing the operator  210  to use two hands for manipulating the handle  108 . In another embodiment, the outboard hand grip  118 B is positioned on the opposite side of the first hand grip  118 A. In still another embodiment, the outboard hand grip  118 B is not used and the operator  210  grips the first hand grip  118 A. 
     FIG. 5 illustrates a foot plate assembly  510  showing the foot plate  116  and its connection to the lever arm  112 . The bottom surface of the foot plate  116  has a cleat  202 , which serves to anchor the plate  116  to the ground. Those skilled in the art will recognize that the cleat  202  configuration will vary depending upon the surface on which the plate  116  is used. For soil, in one embodiment the cleat  202  is a blade formed from a section of angle and in another embodiment, the cleat  202  has prongs, which are embedded into the ground. For hard surfaces such as concrete or tile, instead of a protruding cleat  202 , the cleat is a resilient material with a tread that grips the surface and prevents sliding of the foot plate  116 . 
     Attached to the foot plate  116  is a swivel  512 , which is, in turn, attached to the lever arm  112 , which, in the illustrated embodiment, is made up of a pair of tube members  112 A,  112 B. The means for connecting the lever arm  112  to the foot plate  116  includes the swivel  512  that rotates the lever arm  112  about a swivel pin  514  such that the lifting head  102  can be moved in a circle centered about the swivel pin  514 . The swivel  512 , in one embodiment, is similar to a caster, but without the wheel, and mounted upside-down to the plate  116 . The lever arm members  112 A,  112 B; connect to the swivel  512  with a pivot pin  522  such that the lever arm  112  pivots vertically relative to the foot plate  116 . In the illustrated embodiment, the pivot pin  522  has an axis that is substantially parallel to a plane defined by the foot plate  116 . In the illustrated embodiment, the pivot pin  522  is secured with cotter pins  524 A,  524 B, although one skilled in the art will recognize that any of various means can be used to secure the pivot pin  522  in place. 
     The foot plate assembly  510  includes a lifting plate  232  under which the operator  210  places his toes in order to lift the foot plate assembly  510 . In the illustrated embodiment, the center portion of the lifting plate  232  has an opening for the pivot pin  522  and serves as a spacer for the pair of tube members  112 A,  112 B. The opposite end of the lifting plate  232  has a spring  502  connected between a support  532  and the plate  232 . The spring  502  secures the plate  232  in an elevated position. If the plate  232  is stepped on by the operator  210 , the spring  502  prevents the plate  232  from being bent and allows the plate  232  to return to a position suit able for lifting the foot plate assembly  510 . 
     FIG. 6 illustrates the attachments of the lever arm (second member)  112  and the lifting arm (third member)  106  to the lifting head shaft (first member)  104 . The lifting arm  106  has a series of openings  604 A of which two of the openings have pins  602 ,  612 . The opening  604 A not being used by a pin  602 ,  612  allows for adjustment of the angle of the lifting arm  106  relative to the lifting head shaft  104 . Other openings (not illustrated) in the lifting head shaft  104  allow the combined length of the lifting arm  106  and the lifting head shaft  104  to be varied. 
     A pivot pin  612  passes through the two tube members  106 A,  106 B of the lifting arm  106  and through a corresponding opening in the lifting head shaft  104 . A stop pin  602  passes through the two tube members  106 A,  106 B of the lifting arm  106  and rests against the lifting head shaft  104  when the handle  108  is pushed down by the operator  210 . In the illustrated embodiment, the pins  602 ,  612  are secured with cotter pins, although one skilled in the art will recognize that any of various means can be used to secure the pins  602 ,  612  in place. The pivot pin  612  allows the lifting arm  106  and the lifting head shaft  104  to move relative to each other in a limited manner. In another embodiment, the lifting arm  106  and the lifting head shaft  104  are fixed. relative to each other. 
     FIG. 6 illustrates the joint attaching the lever arm  112  to the lifting head shaft  104 , which is shown in section in FIG.  3 . The lever arm members  112 A,  112 B are secured to the lifting head shaft  104  with a pin  312 , which allows the lever arm  112  to rotate about an axis of the shaft  104  and to change the angle of the lever arm  112  relative to the shaft  104 . The operator  210 , by grasping and twisting the handle  108 , rotates the lifting head shaft  104 , and the lifting head  102 . The amount of rotation is limited by the opening  304  in the shaft  104 . In one embodiment, the rotation is 90°, which allows the lifting head  102  to move from a horizontal position to a vertical position, relative to the axis of the shaft  104 . The lever arm members  112 A,  112 B have additional openings  606 A,  606 B through which the pivot pin  302  can be inserted to adjust the length of the lever arm  112  and, consequently, the distance between the pivot pin  302  and the swivel  512  on the foot plate  116 . Those skilled in the art will recognize that numerous openings can be used to allow a wide range of adjustment without departing from the spirit and scope of the present invention. 
     From the foregoing description, it will be recognized by those skilled in the art that a portable hand-operating lifting device has been provided. The device allows movement of the lifting head within a circle centered about a fixed point on a foot plate. The lifting head can be forced under items or into the ground, and the object lifted can be deposited, in one embodiment, by rotating the lifting head and allowing the lifted item to slide off of the head. 
     While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant&#39;s general inventive concept.