Abstract:
A foot operated cutting device used to perform pruning, shearing, trimming, and similar operations includes a cutting head provided with a spring biased blade cooperating with a jaw, an actuating mechanism in a housing coupled to a foot actuating device. The foot operated cutting device generates power from a force input supplied by a user to the foot actuator.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 09/281,524, filed on Mar. 30, 1999 and issued as U.S. Pat. No. 6,101,725 on Aug. 15, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     Many cutting devices used in gardening include a pair of handle sections which are operated by a hand, and a cutting head attached to the handle sections. The cutting head performs either a scissors action or an anvil-type lopping action. Cutting devices of this type include hand driven pruners, hedge shears, grass shears, and the like. 
     Hand driven devices such as those mentioned above, provide severe drawbacks, especially during extended work periods. Even during times of limited work periods, hand driven cutting devices are limited by the power of the hand itself. In periods of extended work, hand driven cutting devices require that the hand and arm be held in difficult and awkward positions in order to extend reach and to cut at a variety of angles. Placing the hand and arm in awkward positions leads to fatigue of the hand and arm muscles and in the long term can produce problems with tendons, especially in the so-called carpal tunnel areas of the hand and wrist, and further strenuous hand operation may cause blisters of the hand. 
     For professional applications, a variety of powered devices have been developed. For example electric, pneumatic, hydraulic, and gas-powered cutting devices have been developed and used. These devices, although not requiring cutting input to be provided by the hand, still have a number of drawbacks. These drawbacks include high price, due to the complexity of the devices and high weight, due to the power plants for the devices. For example, a battery driven unit requires a heavy pack of batteries that must be carried on an operator&#39;s back. The weight of these battery units may be in the range of 5-10 kilograms, or more. Therefore, although powered devices have as their goal, less fatigue for an operator, because the cutting power is provided by an electric, pneumatic, hydraulic, or gas powered device, fatigue is still produced because an operator is still burdened with the weight of these devices while working in the garden or field. Furthermore, the complexity of these powered devices typically produces bulkiness or awkwardness making it both difficult to transport and difficult to position the cutting head at the proper angle to produce the desired cutting result. 
     There is a need and desire for a foot driven cutting device that has a reduced amount of complexity when compared with other powered cutting devices. 
     There is also a need and desire for a foot driven cutting device for which the legs of an operator provide the cutting force that is transmitted to a cutting head and the hand of the operator is used to control the cutting head. 
     There is also a need and desire for a foot operated cutting devices that does not require any accessories beyond a foot actuator, a cutting device, and a force transmitter connecting the foot actuator and the cutting device. Further still, there is a need and desire for a foot actuated cutting device that provides less fatigue for an operator when compared with traditional hand driven cutting devices. 
     SUMMARY OF THE INVENTION 
     The invention relates to a cutting device including a cutting head, a housing supporting the cutting head, and an actuation mechanism. The actuation mechanism includes a foot actuator, and a flexible force transmitter coupled to the foot actuator on a first end and coupled to the housing on a second end. The actuation mechanism transmits a force input from the foot actuator through the flexible force transmitter and to the cutting head thereby producing a cutting action. 
     The invention further relates to a cutting device including a cutting head, a foot actuator, a flexible force transmitter, and a housing. The flexible force transmitter is coupled to the foot actuator on a first end, and the housing supports the cutting head and includes a drive mechanism. The drive mechanism couples the flexible force transmitter to the blade. The flexible force transmitter receives a force input from the foot actuator and provides a force, through the flexible force transmitter, to the blade. 
     The invention still further relates to a cutting device including a cutting head, a foot actuator, a housing, and a hydraulic hose. The foot actuator has a first hydraulic cylinder coupled thereto. The housing supports the cutting head and a second hydraulic cylinder. The second hydraulic cylinder is coupled to the cutting head. The hydraulic hose is coupled to the first hydraulic cylinder on a first end and coupled to the second hydraulic cylinder on a second end, the hydraulic hose communicates hydraulic fluid between the first and second hydraulic cylinders. The foot actuator receives a force input, the force input is transmitted to the first hydraulic cylinder thereby causing hydraulic fluid to flow through the hydraulic hose and causing movement in the second hydraulic cylinder. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred exemplary embodiments of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like reference numerals denote like elements and; 
     FIG. 1 depicts an operator using a foot operated cutting device; 
     FIG. 2 is a partial cut away view of a cutting head and an elevational view of a foot actuator, the foot actuator being in a non-actuated position and the jaws of the cutting device being open; 
     FIG. 3 depicts the same cutting device and foot actuator as depicted in FIG. 2 but having the foot actuator in an actuated state and depicting the cutting head in a closed state; 
     FIG. 4 depicts the reconfigurability of the cutting device capable of having multiple cutting heads and an extension handle attached thereto; 
     FIGS. 5A and 5B depict an operator using a foot operated cutting device having an extension handle; 
     FIG. 6A depicts a foot actuator that is attachable to a shoe, the foot actuator being in a locked stated; 
     FIG. 6B depicts the foot actuator of FIG. 6A in an actuated but unlocked state; 
     FIG. 6C depicts the foot actuator of FIG. 6A in an unlocked and non-actuated state; 
     FIG. 7 depicts a foot operated cutting device having a hydraulic cylinder at the foot actuator and a hydraulic cylinder at the cutting head. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention relates to cutting tools such as pruners, head shears, or grass shears. However, while the invention as described herein will often be referred to as a pruner, those skilled in the art will appreciate that the mechanisms described herein and their principles of operation can be broadly applied to a wide variety of other cutting implements generally. Referring to FIG. 1, an operator  10  is depicted using a foot operated pruner  20 . Foot operated pruner  20  includes a cutting head  25 , a flexible force transmitter  30 , and a foot actuator  35 . Power is transmitted to the cutting head from the leg muscles  40  of operator  10  as operator  10  presses his heel  45  down on actuator  35 . The force generated by leg muscles  40  is transmitted through flexible force transmitter  30  to the cutting head  25 . It should be noted that although operator  10  is shown using the foot operated pruner  20  with his heel  45 , other portions of the body could be used to provide force to foot actuator  35  including, but not limited to, the operator&#39;s toe  46 . 
     In a preferred embodiment of the present invention, flexible force transmitter  30  may be routed over the shoulder  11  of operator  10  (depicted in FIGS. 1,  5 A, and  5 B) to minimize interference with objects that may be close to operator  10 , such as twigs or branches and the like. As depicted in FIG. 1, flexible force transmitter  30  has sufficient slack so that an arm  13  of operator  10  may be in a multiplicity of positions (one alternative position is depicted by phantom lines in FIG. 1) to place cutting head  25  at different cutting positions. 
     Referring now to FIG. 2, foot operated pruner  20  is depicted in a non-actuated or open state. In other words, foot actuator  35  is not being actuated by heel  45  therefore, cutting head  25  is biased in an open position by a biasing spring  50 . Cutting head  25  includes a blade  52  pivotally coupled to a jaw  54  at a pin  56 . Blade  52  and jaw  54  create a bight  53  designed to receive a workpiece  51 , such as twigs or branches. Blade  56  is pivotally coupled to a connecting link  58  at a pin  60  and jaw  54  is coupled to a housing  62  at a jaw base  64 . Connecting link  58  is pivotally coupled to a rod  66  at a pin  68 . Rod  66  is constrained to slide substantially linearly within housing  62 . The linear travel of rod  66  is limited by a stop  70  that is coupled to rod  66  and engages housing  62  when cutting device  25  is in a fully open position as depicted in FIG.  2 . Rod  66  is also coupled to a cable  72 , cable  72  transmits the force from foot actuator  35  to cutting head  25 . Biasing spring  50  forces rod  66  and therefore blade  52  into the fully open position depicted in FIG. 2 when there is little or no force being transmitted through cable  72 . 
     Cable  72  slides within a sheath  74 , sheath  74  extending between housing  62  and foot actuator  35 . Cable  72  and sheath  74  make up flexible force transmitter  30 . Foot actuator  35  includes a base  76  and a tread  78  pivotally coupled to base  76  at a pin  80 . Sheath  74  is coupled to base  76  and cable  72  is coupled to tread  78  so that when leg muscles  40  of operator  10  produce a force on heel  45 , as depicted in FIG. 3, the rotational movement of tread  78  causes cable  72  to be extended from sheath  74  at base  76 . Therefore, cable  72  transmits a force produced from heel  45  through cable  72  to rod  66 . As depicted in FIG. 3, rod  66  travels in a direction shown by arrow  82 . As rod  66  is pulled in direction  82 , connecting link  58  causes blade  52  to rotate about pin  56  and thereby causing cutting head  25  to come to a closed position as depicted in FIG. 3 whereby blade  52  overlaps or contacts jaw  54 . As depicted in FIG. 3, with bight  53  closed, workpiece  51  has been severed. Because leg muscles  40  are capable of supplying a much greater force to foot actuator  35  than the force that could be supplied by an operator&#39;s hand to the handles of a conventional cutting device, foot operated pruner  20  is able to sever heavier branches than can be severed using a conventional pruner. 
     As rod  66  is moved in direction  82 , biasing spring  50  is compressed as depicted in FIG. 3 thereby storing potential energy. Potential energy stored in biasing spring  50  may be used later to return blade  52  to the open position, as depicted in FIG.  2 . 
     As depicted in FIG. 1, operator  10  holds cutting head  25  in his hand  12 . As depicted in FIGS. 2 and 3, hand  12  grasps housing  62  to position cutting head  25  in the appropriate cutting position and orientation. 
     In one embodiment of the present invention, a variety of cutting heads may be coupled to connecting link  58  at pin  60  and coupled to housing  62 , as depicted in FIG. 4. A variety of cutting implements may be attached to housing  62  and connecting link  58  such as pruner  54 , hedge shears  90 , grass shears  92 , and other cutting devices. Furthermore, an extension handle  94  may be coupled to housing  62  by coupling connecting link  58  to a housing link  96 . Housing link  96  extends out both ends of extension handle  94  such that housing link  96  may be coupled to connecting link  58  on a first end and to the cutting implement such as pruner  54 , head shears  90 , or grass shears  92 , at a second end. 
     As depicted in FIG. 5A, operator  10  is depicted using foot operated cutting device  20  having extension handle  94  coupled to housing  62  and to cutting implement  92 . As depicted in FIG. 5A, operator  10  is able to easily reach foliage that is located substantially above the head of operator  10 , and is able to easily actuate shears  92  by pressing his heel  45  onto tread  78  of foot actuator  35 . 
     Similarly, as depicted in FIG. 5B, operator  10  is positioned to cut foliage that is located substantially below the waist of operator  10  by using foot operated cutting device  20  having extension handle  94  attached to housing  96  at a first end and to shears  92  at a second end. As depicted in FIG. 5B, operator  10  does not have to bend over in a substantial manner in order to cut foliage that is low to the ground because extension handle  94  provides the necessary reach and actuation is simplified by providing actuation through heel  45  of operator  10  to tread  78  of foot actuator  35 . 
     Referring now to FIG. 7, an alternative embodiment of the present invention is depicted. Foot operated cutting device  120  includes a cutting head  125  coupled to a housing  162 , housing  162  being coupled to a hydraulic cylinder  163 , and hydraulic cylinder  163  having a piston  165 . Piston  165  is coupled to a rod  166 , rod  166  being coupled to a connecting link  158  and connecting link  158  being coupled to a blade  152 . Blade  152  is pivotally coupled to a jaw  154  at a pin  156 . Hydraulic cylinder  163  is fluidly coupled to a hydraulic hose  174 . Hydraulic hose  174  has a lumen  172  extending therethrough to communicate hydraulic fluid. 
     A foot actuator  135  has a base  176  and a tread  178  on which a heel  45  transmits a force provided by operator  10 . A hydraulic cylinder  177  is coupled to tread  178 . A piston  179  rides within hydraulic cylinder  177  and is coupled to base  176  by a piston rod  181 . 
     In operation, as heel  45  transmits a force to tread  178 , piston  179  pressurizes hydraulic fluid  183  that is contained within hydraulic cylinder  177 , thereby pushing hydraulic fluid  183  through lumen  172  in hydraulic hose  174  and into hydraulic cylinder  163 . As hydraulic fluid is communicated into hydraulic cylinder  163 , piston  165  pushes rod  166  thereby causing blade  152  to pivot about pin  156  and causing a bight  153 , that is formed by blade  152  and jaw  154 , to close. 
     Once bight  153  is closed, and heel  45  releases pressure from tread  178 , biasing spring  150 , which stored potential energy during the closing process, presses on housing  162  and on a plate  167  that is coupled to rod  167 . Therefore, biasing spring  150  causes piston  165  to pressurize fluid  183  through lumen  172  in hydraulic hose  174  and into hydraulic cylinder  177  thereby returning tread  178  to its unactuated position as depicted in FIG.  7 . 
     Referring now to FIGS. 6A-6C, a foot actuator  235  is depicted. Foot actuator  235  is an alternative embodiment of foot actuator  35 . As depicted in FIG. 6A, foot actuator  235  has a base portion  276  that is pivotally coupled to a tread portion  278 . Tread portion  278  is coupled to a cable  272  and base portion  276  is coupled to a sheath  274 . Foot actuator  235  is configured to be attachable to a shoe  240  by a toe strap  242  and a heel strap  244 . (In another alternative embodiment, foot actuator  235  may be integrated into a special shoe.) Heel strap  244  is coupled to tread portion  278  and toe strap  242  is coupled to tread portion  278  by a toe strap loop  246 . 
     As depicted in FIG. 6A, foot actuator  235  may be locked into an actuated position as shown in FIG. 6A, such that operator  10  would be able to walk with a normal gait having foot actuator  235  attached to shoe  240 , foot actuator  235  not substantially interfering with the normal gait of an operator. Foot actuator  235  is put into a locked or fixed position by operator  10  positioning a hook  250  to engage a bottom bar  277  of base portion  276 . Operator  10  may position hook  250  into the locked position by either performing an appropriate foot movement or by placing actuator  235  into the locked position by hand. In an alternative embodiment it may be possible to lock up foot actuator  235  by locking the cutting head, such as cutting head  25 , in a closed position. As depicted in FIG. 6A, having foot actuator  235  in a locked position causes cutting head  25  to be locked in the closed position. Locking foot actuator  235  into a fixed position is not limited to the hook  250  and bar  277  configuration as depicted in FIGS. 6A-6C, other mechanical configurations may be applied to perform the locking function. 
     As depicted in FIG. 6B, when an operator chooses to use cutting device  20 , hook portion  250  is disengaged from rod  277  such that tread  278  is free to move relative to base  276 , as depicted in FIG.  6 C. FIG. 6C depicts foot actuator  235  in the non-actuated or near non-actuated position, correspondingly a bight such as bight  53  in FIG. 1 would be open. 
     It is understood that the above description is of a preferred exemplary embodiment of the present invention, and that the invention is not limited to the specific forms described. For example, while the invention has been described in association with a device taking the form of a pruner, it can be used with other items as well. In addition, the foot actuator, cutting heads, housings, and actuating mechanisms can take other shapes and forms so long as they can be associated and that the housing is configured to support the drive mechanism and cutting device. Nevertheless, it should be understood that these and other substitutions, modifications, changes, and omissions may be made in the design and arrangement of the elements disclosed herein without departing from the scope of the appended claims.