EP0053938A1
Expired / Lapsed
EP
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Speed setting arrangement for sewing machines
Assignee: Panasonic Holdings Corp
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Filing: 1981-12-07
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Granted: —
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Expires: 2001-12-07
Abstract
Abstract A speed setting arrangement for a sewing machine comprises a permanent magnet (19) mounted for unitary rotation with the foot pedal of the sewing machine, and a magnetic sensor (21) including a plurality of magnetoresistors arranged in pairs to form a bridge circuit on a stationary plane spaced a distance from the plane of rotation of the magnet. The magnetic sensor provides an output signal which is exclusively a function of the magnetic orientation of the magnet and thus serves as a valid indication of the amount of pedal depression. An analog to digital converter (4) is coupled to the magnetic sensor (21) to convert its output into a digital signal for speed control purposes.
Inventors
- 👤 Shigeo Neki
- 👤 Nozomu Shinozaki
- 👤 Takeshi Dohi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 17:34
CPC Classifications
D; D05; D05B; D05B69/00; D05B69/14; D05B69/18; Y; Y10; Y10S; Y10S388/00; Y10S388/923; Y10S388/934
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
73 words
A speed setting arrangement for a sewing machine including a pivotable control pedal, a magnet (19) movable upon movement of the pedal and a magnetic sensor (21), characterised in that the magnet (19) pivots upon movement of the pedal so as to assume an orientation dependent on the pedal position, and in that said magnetic sensor (21) is arranged to detect the magnetic orientation of said magnet and generate a signal representative thereof.
Claim 2
Dependent Claim
73 words
A speed setting arrangement for a sewing machine including a pivotable control pedal, a magnet (19) movable upon movement of the pedal and a magnetic sensor (21), characterised in that the magnet (19) pivots upon movement of the pedal so as to assume an orientation dependent on the pedal position, and in that said magnetic sensor (21) is arranged to detect the magnetic orientation of said magnet and generate a signal representative thereof.
Claim 3
Dependent Claim
78 words
A speed setting arrangement as claimed in claim 1, characterised in that the opposite poles of said magnet (19) are located in diametrically opposite positions with respect to the axis of rotation of the magnet, and in that said magnetic sensor (21) is arranged to be responsive to the vector components of the magnetic flux of said magnet (19) so that the signal generated is an analog signal representative substantially only of the angular displacement of said pedal.
Claim 4
Dependent Claim
36 words
A speed setting arrangement as claimed in claim 2, characterised in that said magnetic sensor (21) includes a plurality of magnetoresistors arranged to detect the vector components of the magnetic flux produced by said magnet (19).
Claim 5
Dependent Claim
36 words
A speed setting arrangement as claimed in claim 3, characterised in that said magnetoresistors are arranged to form a bridge circuit (21) in a stationary plane spaced from the plane of rotation of the magnet (19).
Claim 6
Dependent Claim
36 words
A speed setting arrangement as claimed in claim 4, characterised in that said magnetic sensor (21) includes a differential amplifier (3) coupled to said magnetic sensors in one of the pairs of the bridge circuit (21).
Claim 7
Dependent Claim
96 words
A speed setting arrangement according to any preceding claim, characterised by coupling means between said pedal and said magnet (21) said coupling means including mutually engaged first and second elements (13,16; 26, 26a, 27), the first element (l3;26,26a) being coupled to said pedal for unitary rotation therewith and said second element (16,27) being mounted for rotation with said first element and carrying said magnet (19), and means (18) for urging one of said first and second elements in a circumferential direction so that said first and second elements constantly keep an intimate contact for unitary rotation.
Claim 8
Dependent Claim
49 words
A speed setting arrangement as claimed in claim 6, characterised in that said first element (13:26,26a) extends further from its axis of rotation to the point of contact with said second element (16,27) than said second element (16,27) extends from said point of contact to its axis of rotation.
Claim 9
Dependent Claim
68 words
A speed setting arrangement as claimed in claim 6 or 7, characterised in that each of said first and second elements comprises a lever, one of said levers (13,16) having a connecting pin (15) and the other lever having a recess (16a) for loosely receiving said pin, whereby said pin is urged into pressure contact with one side wall of said recess (16a) by said urging means (18).
Claim 10
Dependent Claim
24 words
A speed setting arrangement as claimed in claim 6 or 7, characterised in that said first and second elements comprise intermeshed toothed members (26,26a,27).
Claim 11
Dependent Claim
33 words
A speed setting arrangement as claimed in any preceding claim, characterised by an analog to digital converter (4) for converting the signal generated by said magnetic sensor (21) into a corresponding digital signal.
Claim 12
Dependent Claim
73 words
A speed setting arrangement as claimed in claim 10, characterised in that said analog to digital converter (4) comprises: a comparator (43) for comparing said analog signal with a reference value to generate a binary output; and means (34-42,50) for applying a binary equivalent potential to said comparator as said reference value in response to said binary output and successively placing a logical "1" bit into one of storage locations of binary significance.
Claim 13
Dependent Claim
66 words
A speed setting arrangement as claimed in claim 11, characterised in that said means (34-42,70) for applying a binary equivalent potential comprises: a resistor network (38-41) having a plurality of resistors of different values which are coupled together to said comparator; and a microcomputer (50) responsive to the output of said comparator for selectively applying a voltage to said resistances to generate said discretely variable voltage.
References Cited (Backward Citations)
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