Dental prophylaxis right angle hand piece

Claim 2

A dental prophylactic right angle hand piece comprising: a. an elongated tubular shank having an inner end and an outer end and a bore extending axially therethrough having inner and outer axially directed open ends respectively at said inner and outer ends of said shank, b. a hollow head having side walls at and integral with said outer end of said shank and two opposite ends one being open and directed at a right angle to said shank and an end wall integral with said side walls closing the other end, said outer end of said bore opening into said head through one side of said side walls, c. an elongated driven member rotatably supported within said head about an axis perpendicular to the axis of said shank, and a tool-holding element integral with said member projecting from said open end of said head for releasable securement of a dental tool thereon, d. an elongated driving spindle rotatably supported within the bore of said shank coaxial therewith having a terminal end portion at the outer end of said bore, e. said spindle and said member respectively including driving means integral with said spindle, and driven means integral with said member in releasable driving relation to each other when said spindle is in operative position within said bore and said member is in operative position within said head, f. said member being freely fully movable through said open end of said head to said operative position with the driven means thereon adjacent the closed end of said head and said driving spindle being freely fully movable through said inner open end of said bore to operative position with said driving means in driving relation to said driven means after said member is in said operative position, g. holding means integral with said spindle at its said terminal outer end in releasable holding engagement with said member for holding said member in its said operative position against removal from the open end of said head, and h. locking means on said shank in engagement with said spindle for holding said spindle and the driven means thereon against retraction from said bore and from said operative position.

Claim 3

In a hand piece as defined in claim 1; i. said driven means comprising an annular row of gear teeth on said member adjacent said end wall of said head and coaxial with the axis of said member, and said driving means comprising an annular row of gear teeth on said spindle coaxial therewith having terminal outer end portions around the outer end of said spindle positioned between the annular row of gears on said member and the open end of said head, said terminal outer end portions being in intermeshing driving relation with the teeth on said member, and j. said holding means comprising the terminal outer end portion of said spindle from which the teeth on said spindle radially extend.

Claim 4

In a hand piece as defined in claim 1; i. a radially outwardly projecting flange on said spindle at the ends of the inner ends of the teeth thereon, and j. said locking means comprising a latch element integral with said shank supported for movement into said bore between said flange and the open inner end of said bore after said spindle is in operative position within said bore.

Claim 5

In a hand piece as defined in claim 2; k. a radially outwardly projecting annular collar integral with said member positioned within the open end of the latter adjacent said tool holding element, and said row of teeth on said member adjacent said end wall of said head projecting radially outwardly of said member for engagement with the outer end portions of the teeth on said spindle, l. the inner surface of the side walls of said head around said collar being cylindrical and providing a bearing surface for the collar and means respectively on said end waLl and said head coaxial with the axis of rotation of said head supporting said member coaxial within said head.

Claim 6

In a hand piece as defined in claim 4; m. the inner surface of said end wall on said head providing a thrust bearing for the said head during rotation of said head and during application of axial force on said head in a direction toward said end wall.

Claim 7

In a hand piece as defined in claim 1; i. said tool holding element comprising a polysided knob providing external corners at the juncture between said sides for frictional engagement with the inner sides of the knob-receiving recess in a elastic walls of a dental polishing tool.

Claim 8

A three-piece, disposable, dental, right angle hand piece consisting of; a. a molded, plastic, one-piece housing for supporting therein for rotation about axes disposed perpendicular to each other a driving spindle rotatable about one of said axes and a driven dental tool-holding member rotatable about the other of said axes said housing including a latch element movable on rail housing to a locking position for holding said driving spindle within said housing in driving relation to said member; and said housing further including bearing surfaces for rotatably supporting said driving spindle and said driven member for rotation about said axes at a right angle to each other; b. a molded, plastic, one-piece driving spindle rotatably supported on one of said bearing surfaces within said housing for rotation about one of said axes, said spindle further including a driving element for releasable connection with a driven element on said member when said spindle and member are in operative positions within said housing for rotating said member by rotation of said spindle, c. a molded, plastic, one-piece driven member rotatably supported on another of said bearing surfaces within said housing for rotation about the other of said axes, said member including a driven element connectable with said driving element for driving by the latter, when said spindle and member are in operative positions within said housing, d. said one-piece driving spindle including means thereon for engaging and holding said driven member in its operative position within said housing against separation of said driven element from said driving element after said driven member has been inserted into said housing to its operative position followed by insertion of said driving spindle to its operative position whereby said driving spindle will hold the three separate pieces of said hand piece in operative assembled relation with said driving and driven elements in driving relation to each other, said driving spindle and said driven member being freely movable into their operative positions within said housing at a right angle to each other, and out of said housing, prior to movement of said latch element to said locking position.

Claim 9

A three-piece, disposable, dental, right angle hand piece consisting of; a. a molded, plastic, one-piece housing for supporting therein for rotation about axes disposed perpendicular to each other a driving spindle rotatable about one of said axes and a driven dental tool-holding member rotatable about the other of said axes said housing including a latch element movable on rail housing to a locking position for holding said driving spindle within said housing in driving relation to said member; and said housing further including bearing surfaces for rotatably supporting said driving spindle and said driven member for rotation about said axes at a right angle to each other; b. a molded, plastic, one-piece driving spindle rotatably supported on one of said bearing surfaces within said housing for rotation about one of said axes, said spindle further including a driving element for releasable connection with a driven element on said member when said spindle and member are in operative positions within said housing for rotating said member by rotation of said spindle, c. a molded, plastic, one-piece driven member rotatably supported on another of said bearing surfaces within said housing for rotation about the other of said axes, said member including a driven element connectable with said driving element for driving by the latter, when said spindle and member are in operative positions within said housing, d. said one-piece driving spindle including means thereon for engaging and holding said driven member in its operative position within said housing against separation of said driven element from said driving element after said driven member has been inserted into said housing to its operative position followed by insertion of said driving spindle to its operative position whereby said driving spindle will hold the three separate pieces of said hand piece in operative assembled relation with said driving and driven elements in driving relation to each other, said driving spindle and said driven member being freely movable into their operative positions within said housing at a right angle to each other, and out of said housing, prior to movement of said latch element to said locking position.

Claim 10

In a hand as defined in claim 7; e. said latch element being locked in its locking position against release after said movement thereof to said locking position.

Claim 11

In a hand piece as defined in claim 7; e. said driving element including external ribs projecting radially outwardly of its axis of rotation providing air-impelling vanes for cooling said spindle and the bearing surfaces therefore.

Claim 12

In a hand piece as defined in claim 7; f. said driven element consisting of an annular row of gear teeth coaxial with the axis of rotation of said member, and g. said means on said spindle for holding said member in its operative position within said housing being a terminal end portion of said spindle engageable with the teeth on said member at the side of said teeth nearest the tool-holder on said member, h. said housing including a wall extending over said member at the side thereof opposite to the side engaged by said means on said spindle.