Abstract:
A tool assembly is disclosed that provides reciprocating motion to a tip of the assembly. The tool assembly has a drive assembly, a shaft assembly and a retraction mechanism contained within a housing. The tip of the shaft assembly protrudes from the housing during a portion of the stroke of the drive mechanism and upon disengagement of a motor of the drive assembly, the tip of the shaft assembly is recessed within the housing of the tool assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/838,741, filed on Aug. 18, 2006, which is incorporated herein by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     This invention relates to a tool assembly for use in cutting and forming various material. More specifically, the invention relates to an assembly to enable a child to cut different types of material and recesses the cutting tip when the tool is not in use. 
     Safety scissors are commonly used by children for cutting different types of material. Safety scissors, however, are difficult for children to effectively cut designs. Thus they may be frustrating for a child to use, especially a young child. 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides a tool assembly that cuts and forms many types of material while remaining easy to use. The tool assembly has a drive assembly and a shaft assembly contained within a housing. The housing may be of various shapes and configurations, and the drive shaft contains a tip that protrudes in its outermost position from an opening in a lower portion of the housing. The drive assembly is operably configured such that the tip is recessed within the housing when the motor of the drive assembly is disengaged. 
     Additional advantages, and novel features of the invention will be set forth in part in a description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       In the accompanying drawings which form a part of the specification and which are to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views: 
         FIG. 1  is a cut-away view of the inner mechanism of the tool assembly of the present invention; 
         FIG. 2  is a cut-away view of the inner mechanism of the tool assembly of the present invention; 
         FIG. 3  is a perspective view of a portion of the housing; and 
         FIG. 4  is a side elevational view of a crown gear and output shaft of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1-4  in greater detail, exemplary embodiment of a tool assembly for cutting and forming materials is shown generally at  10 . The tool assembly includes a housing  12 , a drive assembly  20 , a tip assembly  22 , and a link  24  to connect the drive assembly  20  to tip assembly  22 . 
     The housing  12  may be of various shapes and sizes as will be discussed hereinafter. Tool housing  12  includes a pair of opposed channels  13  that extend longitudinally for a span and serve as guide tracks for a portion of the drive assembly as will be described in greater detail hereinafter. The lower portion of the housing  12  is formed with a removable tip member  16  having an opening  18  extending therethrough. The tip member may be secured through known fastening means, such as screws received in threaded apertures, to retain the tip member on the housing. The housing and tip member are preferably made of a durable, lightweight plastic. 
     The tip assembly  22  comprises a shaft  30  that includes a lower portion having a, cutting tip  32  protruding generally downwardly from the shaft. It will be understood that other tips, such as a forming tip may be substituted for a cutting tip. The tip assembly further includes a shaft guide  34 , which is likewise preferably cylindrical and defines an aperture therethrough to receive reciprocating shaft  30 . The shaft guide  34  is disposed proximate the removable tip  16  of the housing. It will be understood that the shaft guide may be integrally formed with the removable tip member  16 . 
     The drive assembly  20  includes a motor  40  having an output axle such as pin shaft  42 , a gear assembly  50  and a retraction means, generally indicated at  70 . Motor  40  may be battery or electrically powered and is operably configured to minimize vibration of the housing. Preferably the motor is a 12 DC motor and includes a shaft brake (not shown), which may comprise any means for stopping the rotation of pin shaft  42  quickly after the power is disengaged. For example, the shaft brake could be mechanical, such as a piece of felt or other material pressing on the pin shaft  42 , or electrical, such as a high value resistor. 
     The gear assembly  50  comprises a pinion or drive gear  52 , crown gear  54 , and a slidable gearbox housing assembly  56 . Crown gear  52  includes a gear path  53  along its circumferential edge and an aperture  57  at its center of rotation. Drive gear  52  engages crown gear  48  at its gear path  53  and thereby transfers power thereto. Crown gear  54  further includes an output shaft  58  that is connected to a side surface of crown gear. In a preferred embodiment, the crown gear  54  includes a hub  55  projecting from one of the side surfaces of the gear. Aperture  57  of the crown gear extends through hub  55 . The hub is offset from the center of rotation of the crown gear. Crown gear&#39;s  54  aperture extends through hub and is concentric with the axis of rotation of the crown gear  52  but not the center of rotation of the hub. 
     Output shaft  58  includes a collar  59  at one end that is operably configured to be slidably received on the hub  55 . At the other end, output shaft  58  includes a yoke  61  for connection to one end of link  24  at connection  27 . The shaft  30  of the tip assembly  22  is connected to the gear assembly  50  via link  24  through a ball-in-socket joint  25 . 
     The gearbox housing assembly  56  includes a generally U-shaped housing  62  having a base wall  64  and two legs  66  extending therefrom. The U-shaped housing  62  surrounds both the crown gear  54  and pinion gear  52 . The base wall  64  further includes a semi-circular cutout operably configured to fit onto a thrust bearing  80  which will be described in more detail hereinafter. The housing assembly  56  further includes a rod  68  that extends through both legs  66  of the gearbox housing  62  and through the aperture  57  of both the crown gear  54  and the hub  55 . The rod  68  further extends externally of each leg  66  of the U-shaped housing  62 . These externally extending portions of the rod  68  are configured to be received in the channels  13  of tool housing  12 . As assembled, the channels  13  serve to secure the gearbox housing assembly  56  inside the housing  12  while permitting longitudinal movement of the gearbox housing assembly  56 . 
     Retraction means  70  comprises a cam  72  that at a proximate end  74  is connected to and rotates with pin shaft  42  and at a distal end  76  is formed with a bore to receive a follower mechanism  77 . Cam  72  includes a slot  75  extending transversely across the cam  72  and having a first end  79  and second end  78 . The first end  79  of slot  74  is located longitudinally more proximate to the tip assembly  22  of the tool housing  12  than second end  78 . The longitudinal distance that first end  79  and second end  78  are separated by is greater than the stroke of the tip assembly  22 . The stroke of the tip assembly  22  is defined as twice the distance of the offset of the output shaft  58  from the center of crown gear  54 . 
     The follower mechanism  77  comprises a collar  82  having a pin follower  84 , the collar  82  being configured to be rotatably received in the distal end of cam  72 . The pin follower  84  is mounted to collar  82  such that it extends transversely therefrom and is operably configured to be received in slot  74 . The follower mechanism  77  further includes a shaft (not shown) extending longitudinally from the center of rotation of collar  82 , and a flywheel  86  mounted on the shaft. The pinion gear  52  is mounted to the distal end of the shaft and the thrust bearing  80  is rotatably and slidably received on the shaft between the pinion gear  52  and collar  82 . 
     In operation, when motor  40  is activated, the pin shaft  42  drives the cam  72  in a clockwise direction as viewed from the shaft  42  back to the motor  40 . This causes slot  75  to move relative to pin follower  84  of the follower mechanism  77  until the first end  79  of the cam&#39;s slot  75  engages the pin follower  84 , as shown in  FIG. 1 . As the cam  72  moves relative to the pin follower  84 , both the pin follower  84  and the gear assembly  50  through thrust bearing  80  are shifted forward toward the tip  16  of the housing  12 . The gear box housing assembly  56  slides in the channels  13  of the tool housing  12 , which serve as guide tracks for the U-shaped housing  62 . Once the pin follower  84  is engaged by the first end  79  of slot  74 , the cam  72  drives the follower mechanism  77  and, in turn, drives pinion gear  52 . As previously described, the pinion gear  52  transfers the power to crown gear  54 , which rotates about its center to cause the offset output shaft  58  to reciprocate the tip assembly  22 . 
     Upon the motor  40  being disengaged, the shaft brake stops the motor  40  and thus output shaft  42  and cam  72 . The flywheel&#39;s  86  stored kinetic energy continues to drive the follower mechanism  77  and, in particular, collar  82  and pin follower  84 . This causes pin follower  84  to travel from first end  79  to the second end  78  of slot  74 , which, in turn, pulls the follower mechanism  77  and gear box housing assembly  56  through thrust bearing  80  back toward the motor  40  of the tool assembly  10 , as shown in  FIG. 2 . The tip assembly  22 , which is connected to the drive assembly  20  via the ball-in-socket joint of link  24 , is retracted within the tip member  16  of the housing  12 . 
     It is to be understood that the cutting tool assembly may include one or more tips that each are selectively removable from housing. Each tip performs different and are interchangeably mounteable to the housing. 
     All of these embodiments of a tool assembly may be used with an underlying board. The board may supply power to the cutting tool and may further be configured with grooves to facilitate cutting certain shapes, such as, for example, circles, spirals anatomical features, wings and fuselage, and moon shapes. The underlying board further is preferably plastic and may include means to secure the paper or other material to the board to secure the material thereon to facilitate the cutting of the material. In one means of securing the material, the underlying board may have an abraded or rough surface to hold the material to enhance the shearing of the material. 
     The present invention has been described in relation to particular embodiments, which are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its scope. 
     It will be seen from the foregoing that this invention is one well adapted to attain the ends and objects set forth above, and to attain other advantages, which are obvious and inherent in the device. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not limiting.