Electric stepping motor and remote register operated thereby

Claim 2

An electric stepping motor comprising a rotor having the form of a cylindrical permanent magnet providing one north seeking pole at one region of its periphery and a complementary south seeking pole at a diametrically opposite region of its periphery, means rotatably mounting said rotor for rotation about the cylinder axis, a stationary magnetic flux system comprising a pair of main stator poles positioned to lie on diametrically opposite sides of said rotor and at least one further subsidiary pole disposed to face the surface of said rotor at a position displaced by an angle of substantially 90* from the said main stator poles and an electromagnetic magnetizing winding embracing a part of said magnetic flux system to produce opposite magnetic polarities in said main stator poles when traversed by a magnetizing current, the magnetic reluctance of the magnetic flux path around said flux system and through said rotor by way of said subsidiary pole or poles being greater than the reluctance of the equivalent magnetic flux path around said system and through said rotor by way of said main stator poles and operative to provide an output rotary movement of one-half revolution in a given direction in response to one input pulse of a first polarity and of a second-half revolution in the same given direction in response to a following input pulse of opposite polarity.

Claim 3

An electric stepping motor according to claim 1 in which said magnetic flux system comprises members of rectangular section ferromagnetic strip material shaped at one end to provide said main and subsidiary poles and connected towards their opposite ends to a core of an electromagnet.

Claim 4

An electric stepping motor according to claim 2 in which said magnetic flux system comprises a first pole member of rectangular section strip ferromagnetic material bent at right anGles towards one end to form a first main pole and a first subsidiary pole and connected towards its other end to one end of said magnetic core and a second pole member of magnetic strip material reversely bent upon itself near its midregion and then again bent at right angles away from its other end to form a second main pole and a second subsidiary pole, said second pole member being connected towards its other end to the opposite end of said magnetic core.

Claim 5

An electric stepping motor according to claim 2 in which said magnetic flux system comprises a first rectangular section strip of ferromagnetic material bent at right angles towards one end and connected to one end of said magnetic core near its other end and a second unbent strip of rectangular section strip of ferromagnetic material forming the second main pole at one end and connected towards its other end to the opposite end of said magnetic core.

Claim 6

An electric stepping motor according to claim 4 in which said magnetic flux system includes a further member of rectangular section strip of ferromagnetic material bent at right angles towards one end to form a second subsidiary pole and connected towards its other end to the said other end of said magnetic core in face-to-face contact with said second strip member.

Claim 7

An electric stepping motor including a rotor comprising a cylindrical permanent magnet magnetized diametrically to have a single north pole at one region of its periphery and a single complementary south pole at a diametrically opposite region of its periphery, means rotatably mounting said rotor for rotation about the axis of said cylinder, a stationary magnetic flux system comprising a pair of main stator poles each having a flat main polar surface, which main polar surfaces lie parallel with each other on diametrically opposite sides of and with equal flux gap springs from the periphery of said rotor magnet and at least one subsidiary stator pole having a flat subsidiary polar surface lying at an angle of 90* to said main polar surfaces, said subsidiary polar surface facing but being spaced away from the periphery of said rotor magnet, and an electromagnet embracing a part of said magnetic flux system to produce, when energized, opposite magnetic polarities in said main stator poles and the same magnetic polarity in said subsidiary pole as in a given one of said main poles, the magnetic reluctance of the magnetic flux path around said magnetic flux system and through said rotor by way of said subsidiary pole or poles being greater than the corresponding reluctance of the equivalent magnetic flux path around said flux system and through said rotor by way of said main stator poles and providing an output rotary movement of one-half revolution of said rotor in a given direction in response to one input energizing current pulse of a first polarity and a second one-half revolution in the same given direction in response to a following input energizing current pulse of opposite polarity.

Claim 8

An electric stepping motor including a rotor comprising a cylindrical permanent magnet magnetized diametrically to have a single north pole at one region of its periphery and a single complementary south pole at a diametrically opposite region of its periphery, means rotatably mounting said rotor for rotation about the axis of said cylinder, a stationary magnetic flux system comprising a pair of main stator poles each having a flat main polar surface, which main polar surfaces lie parallel with each other on diametrically opposite sides of and with equal flux gap springs from the periphery of said rotor magnet and at least one subsidiary stator pole having a flat subsidiary polar surface lying at an angle of 90* to said main polar surfaces, said subsidiary polar surface facing but being spaced away from the periphery of said rotor magnet, and an electromagnet embracing a part of said magnetic flux system to produce, when energized, opposite magnetic polarities in said main stator poles and the same magnetic polarity in said subsidiary pole as in a given one of said main poles, the magnetic reluctance of the magnetic flux path around said magnetic flux system and through said rotor by way of said subsidiary pole or poles being greater than the corresponding reluctance of the equivalent magnetic flux path around said flux system and through said rotor by way of said main stator poles and providing an output rotary movement of one-half revolution of said rotor in a given direction in response to one input energizing current pulse of a first polarity and a second one-half revolution in the same given direction in response to a following input energizing current pulse of opposite polarity.