Undercut saw height adjustment, handle, blade guard improvements

Abstract

An undercut saw including a motor, a drive shaft rotated by the motor, a blade mount mechanically linked to the drive shaft, the blade mount allowing a saw blade to be mounted and a fixed blade guard circumscribing a portion of the saw blade. The fixed blade guard includes a top plate and a height adjustment skirt in telescoping attachment joined by fasteners. A guide washer including a guide washer slot runner is configured to move up and down in a slot on the height adjustment skirt.

1 . An undercut saw configured to cut a substantially vertical wall surface while a fixed blade guard assembly moves across a substantially horizontal floor surface on which said undercut saw is placed, said undercut saw comprising:
 a rotary power unit having a motor housing;   at least one handle on said motor housing;   a motor housed within said motor housing;   a drive shaft rotated by said motor;   a blade mount mechanically linked to said drive shaft such that when said drive shaft is rotated by said motor, said blade mount is rotated such that when a blade is mounted on said blade mount, said blade is rotated;   a fixed blade guard assembly joined to said motor housing, said fixed blade guard assembly circumscribing a portion of said circular saw blade when said circular saw blade is mounted on said blade mount, said fixed blade guard assembly including:   a top plate fixedly joined to said motor housing, said top plate including a fastener hole;   a height adjustment skirt in telescoping attachment to said top plate, said height adjustment skirt including a fastener slot through to said fastener hole in said top plate;   a guide washer including a substantially horizontal hole alignable with said slot in said height adjustment skirt and alignable with said fastener hole in said top plate;   said guide washer including a guide washer slot runner insertable within a guide washer slot in said height adjustment skirt; and   a guide washer fastener assembly fastenable into said fastener hole in said top plate, through said slot in said height adjustment skirt, and through said substantially horizontal hole in said guide washer;   said guide washer fastener assembly configured such that when in a tightened position it will hold said top plate against an inner surface of said height adjustment skirt, and will hold said guide washer against an outer surface of said height adjustment skirt, such that said top plate is frictionally held against said height adjustment skirt; and   said guide washer fastener assembly configured such that when it is in a loosened position said height adjustment skirt will telescope in relation to said top plate;   wherein when said guide washer fastener assembly is in a loosened configuration, a telescoping motion of said height adjustment skirt is guided by said guide washer slot runner moving within an area confined by the guide washer slot in said height adjustment skirt.   
   
   
       2 . The undercut saw of  claim 1  wherein said guide washer includes a radial shaped face in a flush contact with a guide washer channel of said height adjustment skirt. 
   
   
       3 . The undercut saw of  claim 1  wherein said guide washer slot runner contacts a downwardly protruding back edge of said top plate when said guide washer fastener assembly is in a tightened position. 
   
   
       4 . The undercut saw of  claim 1  further including:
 a lead threaded member rotatably mounted to the height adjustment skirt; and   a substantially vertical tapped hole in said guide washer engaged by the lead threaded member, wherein when said undercut saw is placed with said height adjustment skirt flat on a floor surface, and said guide washer fastener assembly is in a loosened configuration, turning said lead threaded member raises and lowers said top plate.   
   
   
       5 . The undercut saw of  claim 1  further including a removable blade cover being on a bottom surface of said height adjustment skirt, said blade cover covering the blade past a depth of the teeth. 
   
   
       6 . The undercut saw of  claim 1  further including a removable blade cover being on a bottom surface of a downwardly protruding back edge of said top plate, said blade cover covering the blade past a depth of the teeth. 
   
   
       7 . An undercut saw configured to cut a substantially vertical wall surface while a fixed blade guard assembly moves across a substantially horizontal floor surface on which said undercut saw is placed, said undercut saw comprising:
 a rotary power unit having a motor housing;   at least one handle on said motor housing;   a motor housed within said motor housing;   a drive shaft rotated by said motor;   a blade mount mechanically linked to said drive shaft such that when said drive shaft is rotated by said motor, said blade mount is rotated such that when a blade is mounted on said blade mount, said blade is rotated;   a fixed blade guard assembly joined to said motor housing, said fixed blade guard assembly circumscribing a portion of said circular saw blade when said circular saw blade is mounted on said blade mount, said fixed blade guard assembly including:   a top plate fixedly joined to said motor housing, said top plate including a fastener hole;   a height adjustment skirt in telescoping attachment to said top plate, said height adjustment skirt including a fastener slot through to said fastener hole in said top plate;   a lead guide washer including a substantially horizontal hole alignable with a guide washer slot in said height adjustment skirt, and said fastener hole in said top plate, and a substantially vertical tapped hole;   a guide washer fastener assembly fastenable into said fastener hole in said top plate, through said slot in said height adjustment skirt, and through said horizontal hole in said lead guide washer;   said guide washer fastener assembly configured such that when in a tightened position it will hold said top plate against an inner surface of said height adjustment skirt, and it will hold said lead guide washer against an outer surface of said height adjustment skirt, such that said top plate is frictionally held against said height adjustment skirt;   said guide washer fastener assembly configured such that when in a loosened position said top plate will telescope in relation to said height adjustment skirt; and   a lead threaded member threadable into said substantially vertical tapped hole in said lead guide washer, said lead threaded member rotatably fastened to said height adjustment skirt;   wherein when said guide washer fastener assembly is in a loosened position, said top plate is raised and lowered by turning said lead threaded member.   
   
   
       8 . The undercut saw of  claim 7  wherein a radial shaped face of said lead guide washer rests flush against a guide washer channel of said height adjustment skirt. 
   
   
       9 . The undercut saw of  claim 7 , wherein said lead guide washer includes a guide washer slot runner insertable within a slot in said height adjustment skirt. 
   
   
       10 . The undercut saw of  claim 9  wherein said guide washer slot runner contacts a downwardly protruding back edge of said top plate when said guide washer fastener assembly is in a tightened position. 
   
   
       11 . An undercut saw configured to cut a substantially vertical wall surface while a fixed blade guard assembly moves across a substantially horizontal floor surface on which said undercut saw is placed, said undercut saw comprising:
 a motor configured to produce rotational movement about a first axis of rotation and a spindle rotatably powered by said motor for rotation about a second axis of rotation which is perpendicular to the first axis of rotation;   a motor housing enclosing said motor and said spindle, said motor housing including a spindle housing having a toothed surface formed on an outer surface, said spindle housing including a spindle housing handle mounting hole proximate to said toothed surface;   a handle with a toothed surface on an inner face and a handle mounting hole proximate to said toothed surface, said toothed surface of the handle interlockable with said toothed surface on said spindle housing; and   a handle fastening fastener fastening said handle to said spindle housing at said spindle housing handle mounting hole;   wherein when said handle fastening fastener fastens said handle on said spindle housing, with said toothed surface on said handle interlocked with said toothed surface on said spindle housing, said handle is prevented from rotating.   
   
   
       12 . The undercut saw of  claim 11 , wherein said spindle housing has two toothed surfaces on opposite outer side surfaces and two handle mounting holes proximate to said two toothed surfaces, a handle including two toothed surfaces on opposite inside surfaces interlockable with said two toothed surfaces on said spindle housing, and two handle fastening fasteners, wherein when said two handle fastening fasteners fasten said handle to said spindle housing at said two handle mounting holes, with said two toothed surfaces on said handle interlocked with said two toothed surfaces on said spindle housing, said handle is prevented from rotating. 
   
   
       13 . The undercut saw of  claim 12 , further including said handle having two handle sections joined at a pivot. 
   
   
       14 . The undercut saw of  claim 11 , wherein:
 said handle further includes a boss on said inner face of said handle proximate to said handle mounting hole; and   when said handle is oriented at a preset angle and position in relation to said first axis of rotation, said boss contacts said spindle housing preventing said toothed surface on said handle from interlocking with said toothed surface on said spindle housing.   
   
   
       15 . An undercut saw configured to cut a substantially vertical wall surface while a fixed blade guard assembly moves across a substantially horizontal floor surface on which said undercut saw is placed, said undercut saw comprising:
 a motor configured to produce rotational movement about a first axis of rotation and a spindle rotatably powered by said motor for rotation about a second axis of rotation which is perpendicular to the first axis of rotation;   a motor housing enclosing said motor, said motor housing including a spindle housing enclosing said spindle, said spindle housing including a spindle housing handle mounting hole;   a handle rotatably fastenable to said spindle housing at said spindle housing handle mounting hole, said handle having an inner surface including a boss and a handle hole proximate to said boss; and   a fastener rotatably fastening said handle to said spindle housing at said spindle housing handle mounting hole;   wherein when said handle is rotated towards said spindle housing, said boss contacts said spindle housing to stop said handle from rotating past a preset angle in relation to the motor's first axis of rotation.   
   
   
       16 . An undercut saw configured to cut a substantially vertical wall surface while a fixed blade guard assembly moves across a substantially horizontal floor surface on which said undercut saw is placed, said undercut saw comprising:
 a rotary power unit having a motor housing;   at least one handle on said motor housing;   a motor housed within said motor housing;   a drive shaft rotated by said motor;   a blade mount mechanically linked to said drive shaft such that when said drive shaft is rotated by said motor, said blade mount is rotated such that when a circular saw blade having teeth is mounted on said blade mount, said circular saw blade is rotated;   a fixed blade guard assembly joined to said motor housing, said fixed blade guard assembly circumscribing a portion of said circular saw blade when said circular saw blade is mounted on said blade mount, said fixed blade guard assembly including:   a top plate fixedly joined to said motor housing;   a height adjustment skirt in telescoping attachment to said top plate;   a removable blade cover on a bottom surface of said height adjustment skirt, said blade cover covering the circular saw blade past a depth of the teeth.   
   
   
       17 . The undercut saw of  claim 16  further including:
 a guide washer contacting a guide washer channel on said height adjustment skirt;   said guide washer having a guide washer slot runner slightly narrower than and fitting in a slot in said height adjustment skirt;   a guide washer fastener assembly engaging a downwardly protruding back edge of said top plate through a hole in said guide washer;   said guide washer fastener assembly when tightened applying a frictional holding force to said guide washer, said height adjustment skirt and said downwardly protruding back edge of the top plate;   said guide washer fastener assembly when loosened decreasing a frictional holding force so that said height adjustment skirt telescopes with respect to said top plate.   
   
   
       18 . An undercut saw configured to cut a substantially vertical wall surface while a fixed blade guard assembly moves across a substantially horizontal floor surface on which said undercut saw is placed, said undercut saw comprising:
 a rotary power unit having a motor housing;   at least one handle on said motor housing;   a motor housed within said motor housing;   a drive shaft rotated by said motor;   a blade mount mechanically linked to said drive shaft such that when said drive shaft is rotated by said motor, said blade mount is rotated such that when a circular saw blade having teeth is mounted on said blade mount, said circular saw blade is rotated;   a fixed blade guard assembly joined to said motor housing, said fixed blade guard assembly circumscribing a portion of said circular saw blade when said circular saw blade is mounted on said blade mount, said fixed blade guard assembly including:   a top plate fixedly joined to said motor housing;   a height adjustment skirt in telescoping attachment to said top plate; and   a removable blade cover on a bottom surface of a downwardly protruding back edge of said top plate, said blade cover covering the circular saw blade past a depth of the teeth.   
   
   
       19 . The undercut saw of  claim 18  further including:
 a guide washer contacting a guide washer channel on said height adjustment skirt;   said guide washer having a guide washer slot runner slightly narrower than and fitting in a slot in said height adjustment skirt;   a guide washer fastener assembly engaging a downwardly protruding back edge of said top plate through a hole in said guide washer;   said guide washer fastener assembly when tightened applying a frictional holding force to said guide washer, said height adjustment skirt and said downwardly protruding back edge of the top plate;   said guide washer fastener assembly when loosened decreasing a frictional holding force so that said height adjustment skirt telescopes with respect to said top plate.