Mortiser

Abstract

A mortiser has a housing mounted on a support post and there is a collet on the housing for holding a mortise chisel. A chisel drive coupling is on the housing. A chisel drive shaft extends through the housing and connects with the chisel drive coupling. A reciprocal engagement mechanism is capable of selectively engaging the chisel drive coupling. An operating lever may thus be quickly indexed so that the mortise chisel may be filly lowered without the user pulling the operating lever fully toward him/her and downward. The mortiser also has a finely adjustable ram fence and a depth stop. The collet has a notched or elliptical bore to prevent jamming of the chisel shank in the collet.

I claim:  
     
         1 . A mortiser for making a mortise cut in a work piece comprising: 
 a base;    a table mounted on the base;    a housing supported above the base;    a collet connected with the housing for receiving a mortise chisel shank;    a motor;    a chisel drive shaft extending through the housing;    a chisel drive coupling attached to the chisel drive shaft;    a collet lowering mechanism connected with the chisel drive shaft;    a reciprocal engagement mechanism capable of selectively engaging the chisel drive coupling; and    an operating lever attached to the reciprocal engagement mechanism for rotating the chisel drive shaft and for reciprocating the reciprocal engagement mechanism into and out of engagement with the chisel drive coupling,    whereby when the coupling and reciprocal engagement mechanism are engaged and an operator pulls the lever, the chisel drive shaft and the collet lowering mechanism cooperate to lower the collet toward the work piece.    
     
     
         2 . The mortiser of  claim 1 , wherein the collet includes a chisel shank removal device to prevent a chisel shank from becoming frozen or stuck in the collet bore.  
     
     
         3 . The mortiser of  claim 1 , wherein the reciprocal engagement mechanism and the chisel drive coupling include recessed portions and raised portions which may be intermeshed to engage the reciprocal engagement mechanism with the chisel drive coupling.  
     
     
         4 . The mortiser of  claim 1 , further including two chisel drive couplings attached to the left side and right side of the housing, respectively, to provide for left hand or right hand operation of the mortiser.  
     
     
         5 . The mortiser of  claim 4 , wherein the operating lever and reciprocal engagement mechanism may be selectively engaged and disengaged from the right hand and left hand chisel drive couplings.  
     
     
         6 . The mortiser of  claim 1 , wherein the reciprocal engagement mechanism comprises: 
 a lever insert received in a cylindrical body;    a piston carrying a spring, both housed in the cylindrical body, a protruding end of said piston being receivable in a bore on said chisel drive coupling;    the lever insert having means for engaging an operating lever thereto; and    the lever insert also having means for biasing the lever insert in an upright position.    
     
     
         7 . The mortiser of  claim 6 , wherein the means for biasing the lever insert include a threaded portion at an end of the lever insert, a nut threadably attached to the threaded portion, and a second spring carried on the lever insert and positioned between the nut and the lower side of the body.  
     
     
         8 . The mortiser of  claim 6 , wherein the spring housed in the cylindrical body is configured to bias the reciprocal engagement mechanism into engagement with the chisel drive coupling.  
     
     
         9 . The mortiser of  claim 8 , wherein the piston includes a head and said spring bears on said head.  
     
     
         10 . The mortiser of  claim 1 , wherein the base includes a rack and pinion mechanism, capable of moving the table in a left or right direction, comprised of a table pinion and a table rack, wherein the table pinion is in contact with and engaged with the table rack.  
     
     
         11 . The mortiser of  claim 1  comprising an adjustable fence on an upper surface of the table.  
     
     
         12 . The mortiser of  claim 11 , wherein the adjustable fence comprises: 
 a block having a threaded internal bore attached to the upper surface of the base;    a fence adjust screw having a fence end and a wheel end, the fence end in fixed contact with an equipment side of the adjustable ram fence and threadably connected to and passing through the threaded internal bore of the block; and    at least one fence ram assembly comprised of at least one positive stop slidably attached to a cylindrical ram, a post having an internal bore, a set screw hole, and a set screw with set screw handle, the cylindrical fence ram being journaled in the bore hole of the post and attached to the equipment side of the fence.    
     
     
         13 . The mortiser of  claim 12  comprising two fence ram assemblies.  
     
     
         14 . The mortiser of  claim 12  including two positive stops slidably attached to said cylindrical ram and positioned on either side of said post.  
     
     
         15 . The mortiser of  claim 1 , wherein the collet lowering mechanism comprises a pinion attached to said chisel drive shaft, the pinion engagable with a notched support post extending between said base and said housing.  
     
     
         16 . The mortiser of  claim 1 , wherein an accessory holder is attached to the rear side of the housing.  
     
     
         17 . A method of abrading a work piece using a motorized machine which is configured to vertically engage and disengage a cutting tool with the work piece, comprising the steps of: 
 (a) positioning the work piece below the cutting tool;    (b) engaging an operating lever with a drive coupling on the machine, the drive coupling mechanically interconnected with the cutting tool so as to permit upward and downward movement of the cutting tool;    (c) lowering the cutting tool a first increment toward the work piece by pulling the lever from a first position to a second position;    (d) disengaging the lever from the drive coupling;    (e) repositioning the lever to the first position;    (f) reengaging the lever with the drive coupling; and    (g) further lowering the cutting tool a second increment by again pulling the lever from the first position to the second position.    
     
     
         18 . The method of  claim 17 , wherein the machine is a mortising machine and the cutting tool is a mortising chisel.  
     
     
         19 . The method of  claim 17 , wherein the operating lever carries a reciprocal engagement mechanism which has teeth that reciprocally engage with teeth on the drive coupling.  
     
     
         20 . The method of  claim 17 , wherein the operating lever is disengaged from the drive coupling by pivoting the operating lever outward.  
     
     
         21 . A mortiser for making a mortise cut in a work piece, comprising: 
 a base;    a table mounted on the base;    a housing supported above the base;    a collet mounted on the housing for receiving a mortise chisel shank;    a motor;    a mechanism for raising and lowering the collet; and    the collet having a chisel shank removal device in an interior bore of the collet to facilitate removal of the chisel shank from the collet.    
     
     
         22 . The mortiser of  claim 21 , wherein the chisel shank removal device is a notch extending the length of the internal bore in the collet.  
     
     
         23 . The mortiser of  claim 21 , wherein the chisel shank removal device is an elliptical-shaped internal bore in the collet.  
     
     
         24 . A machine for abrading a work piece, comprising: 
 a base;    a table mounted on the base;    a housing supported above the base;    a mechanism for holding a cutting tool, extending downward from the housing;    a motor; and    an adjustable fence positioned on an upper surface of the table, with at least one fence ram assembly connected with the adjustable fence,    wherein the fence ram assembly comprises at least one positive stop slidably attached to a cylindrical ram, a post having an internal bore, a set screw hole, and a set screw with set screw handle, the cylindrical fence ram being journaled in the bore of the post and attached to the rear side of the adjustable fence.    
     
     
         25 . The machine of  claim 24 , wherein the machine is a mortiser and wherein there are two fence ram assemblies positioned behind the adjustable fence.  
     
     
         26 . The machine of  claim 24 , including two positive stops slidably attached to the cylindrical ram, one positioned on either side of said post.  
     
     
         27 . A mortiser for making a mortise cut in a work piece, comprising: 
 a base;    a table mounted on the base;    a housing supported above the base;    a collet extending downward from the housing for receiving a mortise chisel shank, the collet having a device to facilitate removal of the chisel shank from the collet;    a motor;    a chisel drive shaft extending through the housing;    a chisel drive coupling attached to the chisel drive shaft;    a collet lowering mechanism connected with the chisel drive shaft;    a reciprocal engagement mechanism capable of selectively engaging the chisel drive coupling; and    an operating lever attached to the reciprocal engagement mechanism for rotating the chisel drive shaft and for reciprocating the reciprocal engagement mechanism into and out of engagement with the chisel drive coupling,    whereby when the coupling is engaged and an operator pulls the lever, the chisel drive shaft and the collet lowering mechanism cooperate to lower the collet toward the work piece, and    further including an adjustable fence positioned on an upper surface of the table, the adjustable fence having at least one fence ram assembly positioned behind the fence, the fence ram assembly comprising at least one positive stop slidably attached to a cylindrical ram, a post having an internal bore, a set screw hole, and a set screw with set screw handle, the cylindrical fence ram being journaled in the bore hole of the post and attached to the rear side of the adjustable fence.