Patent Publication Number: US-4653232-A

Title: Apparatus for sharpening a plurality of tools

Description:
BACKGROUND OF THE INVENTION 
     Proper sharpening of tools, such as jointer blades, chisels, and lawn mower blades can restore the cutting edge of the tools to a condition equal to or better than the original cutting edge provided by the manufacturer if the sharpening operation is carried out with great skill and with the proper equipment. Most people, however, do not have the proper equipment for achieving a like-new cutting edge on a worn cutting implement. Furthermore, very few people have developed the talent of resharpening tools to the extent that they can manually hold the tool to be sharpened and manipulate the tool respective to a rotating grinding wheel and achieve a superior cutting edge. 
     Tool grinders for resharpening cutting implements are known to those skilled in the art as evidenced by the following patents: 
     
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         222,539                                                          
              2,183,995                                                   
       1,060,170                                                          
              2,705,391                                                   
       1,197,619                                                          
              3,735,533                                                   
       1,493,346                                                          
              4,052,174                                                   
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     The present invention constitutes an improvement over the above recited prior art in that a tool grinder with attachments therefor is provided by which the average person with very little training can properly mount several tools to be sharpened into a special tool holder, adjust the relative position of a grinding wheel respective to the tools to be sharpened, properly orient the cutting edge of the tools respective to the grinding wheel, and thereafter achieve a cutting edge on the plurality of tools that is equal to or better than the original cutting edge provided by the manufacturer. 
     SUMMARY OF THE INVENTION 
     Tool sharpening apparatus by which the cutting edge of a plurality of tools can be dressed so that the cutting edge thereof is restored to a satisfactory cutting condition. A tool holder releasably receives the tools. The cutting edges of the individual tools are oriented to lie along a common longitudinally extending line. A rotating grinding wheel is positioned for movement towards the tool holder and also parallel to the common longitudinally extending line. The tool holder can be rotated axially along a line parallel to and spaced from the longitudinally extending line. The tool holder and the grinding wheel are mounted for movement to a main frame by means of a slide assembly. 
     The slide assembly includes spaced slide members which are slidably received by spaced guide members. The guide members are affixed to a main frame. A lower plate member is affixed to the slide members. Means are provided for movement of the slide members along the guide members and thereby effect longitudinal movement into the lower plate member respective to the tool holder. 
     The slide assembly includes an upper plate member mounted for movement respective to the lower plate member. Movement of the upper plate member effects lateral movement between the grinding wheel and the tool holder. 
     The grinding wheel is mounted to the plate member, and relative movement of the upper and lower plate members provide for the above described movement of the grinding wheel respective to the cutting edge of the tools held by the tool holder. 
     The tool holder is comprised of an elongated member having bracket means at opposed ends thereof by which the tool holder is mounted to the main frame in an axially rotatable manner. Fastener means are provided by which the tool holder is secured against rotation. 
     The tool holder includes spaced parallel faces interrupted by a longitudinal vertical flange member. A movable clamp member is threadedly secured to the tool holder and forms a clamp between the confronting faces of the flange and clamp member between which the plurality of tools are releasably received. 
     The first and second plate members are moved respective to one another by a threaded screw which has an end attached to the first plate member and a threaded bracket attached to the second plate member so that rotation of the screw effects relative movement between the first and second plate members, and moves the grinding wheel towards the tool holder. 
     The first plate member is moved respective to the main frame by a screw threadedly received by a bracket. The bracket is attached to the main frame and the end of the screw is attached to the first plate member so that rotation of the screw moves the grinding wheel along a path which is parallel to the tool holder. 
     In another embodiment of the invention, the first plate member is moved respective to the frame by a windless means. 
     A primary object of this invention is the provision of a tool sharpener for simultaneously sharpenihg a plurality of tools. 
     Another object of this invention is the provision of a tool sharpener having a tool holder within which a plurality of tools are removably mounted in a manner which enables the cutting edges thereof to be aligned along a common line. 
     A still further object of this invention is the provision of a tool sharpener having a tool holder and a grinding wheel mounted to a frame and arranged whereby a plurality of tools are releasably held oriented in an optimum position respective to the surface of the grinding wheel. 
     An additional object of the present invention is the provision of a tool sharpener having a tool holder and grinding wheel adjustably mounted to a frame, wherein the tool holder receives a plurality of tools thereon, while the grinding wheel can be moved along the cutting faces of the tools in a manner to renew the cutting edge of all the tools in a single operation. 
     These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings. 
     The above objects are attained in accordance with the present invention by the provision of a combination of elements which are fabricated in a manner substantially as described in the above abstract and summary. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elcvational view of a tool grinder made in accordance with the present invention; 
     FIG. 2 is a perspective view of the tool grinder seen in FIG. 1, with some parts thereof being removed therefrom so as to fully disclose the otherwise hidden details; 
     FIG. 3 is an end view of the apparatus seen in FIGS. 1 and 2; 
     FIG. 4 is a perspective view showing the side opposite of the apparatus disclosed in FIG. 1; 
     FIG. 5 is a top, plan view of the apparatus disclosed in FIGS. 1-4; 
     FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. 5; FIG. 7 is a cross sectional view taken along line 7--7 of FIG. 1; 
     FIG. 8 is a perspective, side view of an alternant embodiment of the present invention; and, 
     FIG. 9 is a diagrammatical, representation which sets forth part of the details of the apparatus disclosed in FIG. 8. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the figures of the drawings, there is disclosed a tool sharpenihg apparatus 10 for simultaneously grinding a new cutting face or cutting edge onto a plurality of tools such as chisels, lawn mower blades, jointer blades, and planer blades for example. The apparatus 10 includes a tool bar 12, made in accordance with this invention, which releasably captures a number of tools of different configurations, in a manner which aligns the cutting faces of the tools along a common line. A grinder wheel 14 is spaced from the tool bar and driven by motor 16. The grinder wheel 14 and motor 16 are mounted to a slide assembly 18 which enables the grinding wheel to be moved in either of two directions which is perpendicular and parallel respective to the longitudinal axis of the tool bar 12. 
     A bracket 20 is affixed to a movable lower plate member 22. The bracket 20 threadedly receives a screw 24. The screw 24 has a free end connected to actuator handle 25, with the other end thereof being attached in a captured manner to an upper plate member 48 so that as the handle 25 is rotated, the screw 24 moves the plate member 48, and thereby moves the grinding wheel 14 towards and away from the tool bar 12. 
     A pair of parallel, spaced guide bars 26, 26&#39; slidably receive sleeves 28, 28&#39; thereon so that the sleeves are reciprocated in a slidable manner respective to the guide bar. The slidable lower plate member 22 is affixed to the sleeves 28, 28&#39; and move therewith in a direction parallel to the longitudinal axis of the tool bar 12. 
     Motor 30 is connected to a reduction gear box, which in turn is connected to a drive train for moving the lower plate member 22 and thereby moving the motor 16 and grinder 14 longitudinally of the tool bar. 
     A main frame 32 includes spaced horizontal members to which there is connected the illustrated spaced vertical frame members 34. L brackets 36 are attached to the vertical frame members 34 and are releasably connected at the opposed ends of the tool bar 12 by means of opposed bolts 38. 
     As best seen in FIG. 2, together with other figures of the drawings, a shaft 40 is located between guide bars 26, 26&#39; and arranged parallel thereto. The shaft 40 has a threaded surface formed thereon which threadedly engages a threaded housing 42. The housing 42 is attached to the lower plate member 22. One end of the threaded shaft 40 is journaled to the main frame while the other end thereof is connected to the output shaft of the gear box driven by the motor 30. 
     As seen in various figures of the drawings, and in particular FIGS. 1, 2, and 7, the slide assembly 18 for motor 16 and grinder 14 includes lower spacer member 43 located in fixed relationship respective to the plate lower member 22, a narrow intermediate spacer 44, and an upper spacer member 46. Members 43 and 46 are therefore spaced apart by means of narrow spacer 44 an amount to admit the upper plate 48 to be reciprocatingly received in a slidable manner within the opposed parallel grooves 47 formed between members 43 and 46. 
     In FIGS. 1-3, a shield 50 has a fixed end connected to one end of lower plate member 22, and an upper surface which underlies grinding wheel 14 and thereby forms a bearer which procludes the residue from the grinding operation from contaminating some of the vital parts of the apparatus 10 or 110. 
     The grinder wheel 14 is rotatably supported from upper plate member 48 by means of journals 52. Pulley 53 is connected to the illustrated output pulley of motor 16. The motor is provided with suitable prior art electrical conduits and switch means, the details of which can take on several different forms. 
     As seen in various different figures of the drawings, and in particular FIGS. 4-6, the tool bar or tool holder 12 has a main body portion 54, preferably circular in original cross-sectional configuration, which terminates in a flat at 56 and 57. The flats 56 and 57 are interrupted by the illustrated vertical flange 58. The flange is apertured and threaded at a plurality of locations as indicated by numeral 60, so that a threaded fastener 62 can be extended therethrough and into abutting engagement with a clamping bar 64. The circular part 54 of the tool bar terminates in a stop means at 66. The tool bar 12 preferably is fabricated from a 2&#34; outside diameter solid bar by milling the flats 56 and 57 thereon, thereby leaving flange 58 and stop 66. Next, apertures 60 and 59 are formed into the flange and opposed ends, respectively, of the bar. As seen in FIG. 6, a packet 68 is formed between the clamping bar and stop means 66 so that various different configurations of chisels and other blade members can be easily and safely mounted in a removable manner within the tool bar. 
     FIGS. 8 and 9 illustrate a second embodiment 110 of the invention. The second embodiment 110 of the invention is essentially of identical construction as the first embodiment 10, with the exception of the drive means by which the upper plate member 48 is moved longitudinally and laterally respective to the tool bar 12. 
     The apparatus for moving upper plate member 48 longitudinally of the tool bar 12 comprises a windlass 70 journaled between guide bars 26, 26&#39;. The windlass 70 is rotated by a handle 72. Opposed ends of cable roved about the windlass in opposite directions, turns with one marginal end of the cabel extending several about a marginal length of the windlass 70, and then is roved through pulley 76, then through pulley 78, and into attached relationship at 80 respective to the upper plate member 48. The other marginal length 82 of the cable is similarly roved about the pulleys and connected back to the upper plate 48 at a location such as indicated by numeral 84. Rotation of the windlass in one direction drives the plate 48 in one direction along the tool bar, while rotation of the windlass in the opposite direction moves the plate in the other direction. Bell crank 84 is pivoted to the lower plate member and connected to the upper plate member by tie rod 86. Handle 88, when moved, imparts sliding movement into the upper plate member and thereby moves the grinding wheel towards the tool bar 12. Lock means 87 prevents relative movement between plate members 22 and 48. 
     In operation, a tool to be sharpened is placed between the jaws 66 and 64 of the tool bar 12 and captured therewithin by making up the threaded fastener 62. The cutting edges of all of the tools mounted on the tool bar are oriented in the same direction so that they each may be sequentially sharpened and dressed each pass of the rotating face of the grinding wheel 14 respective thereto. The surface of the grinding wheel is properly positioned in aligned relationship respective to the cutting face of the tool to be dressed. This is achieved by loosening the fastener 38 located at either end of the tool bar 12 and rotating the tool bar along its longitudinal axis. The abrasive face of the grinding wheel 14 is next positioned in proper alignment respective to the cutting face of the tool by manipulating handle 25. Manipulation of handle 25 slides the upper plate member 48 towards and away from the cutting edge of the tools T. Next, motor 30 is energized to turn the threaded shaft 40, thereby moving lower plate member 22 longitudinally respective to the tool bar, so that the properly oriented abrasive surface of the grinding wheel 14 sequentially contacts and dresses the cutting edge of each of the tools at the most optimum relative angle thereto. The motor 30 can be reversed after traveling across all of the faces of the tools T, and thereby provide a fine cut. 
     In the present invention, the sharp edge of the cutting tool is exposed to the operator&#39;s view rather than hidden, so that the operator of the apparatus 10 can closely monitor the grinding operation. The tool bar is uniquely designed to properly accept various different configurations of cutting tools that need dressing from time to time. One of the primary purposes achieved by this invention is the provision of a sharpening machine that is inexpensive and most anyone can use with very little mechanical aptitude. The tools received on the tool bar can often be mixed, that is, it is possible to sharpen a chisel, planer blade, jointer blade, and the like in a single operation. 
     The motor 30 is mounted in a manner to provide precise movement along a path which is parallel to the shaft thereof and also to the tool bar. 
     The movement of plates 22 and 48, together with the oscillatory movement of the tool bar 12, enables the abrasive surface of the grinding wheel to be placed in the most optimum position for providiing a superior cutting face on the various different tools to be dressed.