Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
247 words
A drive mechanism for a typewriter having a member to be cyclically driven in one direction, comprising: a first rotatable element; a second rotatable element having a common axis of rotation with said first element and operatively coupled to said member; an electric motor coupled to said first element and selectively energizable to rotate said first element in one direction for a cycle of operation of said member; a clutch spring in continuous frictional engagement with said first and second elements such that said clutch spring only imparts rotation of said first element in said one direction relative to said second element and rotation of said second element in the opposite direction relative to said first element; holding means having a first position in which said holding means positively holds said second element to a particular angular position about said axis and a second position in which said holding means releases said second element; and control means operable prior to and including initiation of energization of said motor to bring said holding means from said first to said second position and operable prior to and including completion of a cycle of rotation of said first element as well as said second element in said one direction to bring said holding means from said second to said first position to cause said second element as well as said first element to be positively held to a next particular angular position upon completion of the cycle of said rotation.
Claim 2
Dependent Claim
247 words
A drive mechanism for a typewriter having a member to be cyclically driven in one direction, comprising: a first rotatable element; a second rotatable element having a common axis of rotation with said first element and operatively coupled to said member; an electric motor coupled to said first element and selectively energizable to rotate said first element in one direction for a cycle of operation of said member; a clutch spring in continuous frictional engagement with said first and second elements such that said clutch spring only imparts rotation of said first element in said one direction relative to said second element and rotation of said second element in the opposite direction relative to said first element; holding means having a first position in which said holding means positively holds said second element to a particular angular position about said axis and a second position in which said holding means releases said second element; and control means operable prior to and including initiation of energization of said motor to bring said holding means from said first to said second position and operable prior to and including completion of a cycle of rotation of said first element as well as said second element in said one direction to bring said holding means from said second to said first position to cause said second element as well as said first element to be positively held to a next particular angular position upon completion of the cycle of said rotation.
Claim 3
Dependent Claim
29 words
A drive mechanism as claimed in claim 1, wherein said clutch spring allows said first element to assume any angular position relative to said second position about said axis.
Claim 4
Dependent Claim
37 words
A drive mechanism as claimed in claim 2, wherein said clutch spring is so constituted as to provide a particular angular displacement between said first and second elements by each cycle of rotation of said second element.
Claim 5
Dependent Claim
44 words
A drive mechanism as claimed in claim 3, wherein said clutch spring is coiled around and has a relatively weak frictional engagement with portions of said first and second elements so as to provide said particular angular displacement between said first and second elements.
Claim 6
Dependent Claim
70 words
A drive mechanism as claimed in claim 1 or 2, wherein said motor is a bidirectional motor which may be energized again for a rather short period of time, after completion of one cycle of rotation of said second element, to rotate said first element in the opposite direction to provide an angular displacement of said first member relative to said second member in the opposite direction about said axis.
Claim 7
Dependent Claim
20 words
A drive mechanism as claimed in claim 1, 2, 3, or 4, wherein said motor is a small DC motor.
Claim 8
Dependent Claim
83 words
A drive mechanism as claimed in claim 1, 2, 3, or 4, wherein said holding means includes a first stop member mounted for engagement with said second element to positively stop rotation of said second element in said one direction, and a second stop member mounted for engagement with said second element to positively stop possible reactive rotation of said second element in the opposite direction when rotation of said second element in said one direction is stopped by said first stop member.