Capacitor winding apparatus

Claim 2

Apparatus for automatically producing wound capacitor elements from a composite strip, comprising (a) a mandrel; (b) a drive for rotatably driving the mandrel; (c) automatic timing means for starting and stopping rotation of the mandrel; (d) means for folding the leading end of the composite strip around the mandrel; (e) a temporary clamp for engaging the composite strip; (f) means for sensing the tension in the length of composite strip between the mandrel and the temporary clamp; and (g) means for starting up the automatic timing means when, upon rotation of the mandrel, an increase in tension in said length operates the sensing means as an indication that the leading end of the composite strip has been successfully folded around the mandrel and trapped, so that winding can commence.

Claim 3

Apparatus for automatically producing wound capacitor elements from a composite strip comprising (A) a mandrel; (b) a drive for rotatably driving the mandrel; (c) automatic timing means for starting and stopping rotation of the mandrel; (d) means for folding the leading end of the composite strip around the mandrel; (e) a temporary clamp for engaging the composite strip; (f) means for sensing the tension in the length of composite strip between the mandrel and the temporary clamp; (g) means for starting up the automatic timing means when, upon rotation of the mandrel, an increase in tension in said length operates the sensing means as an indication that the leading end of the composite strip has been successfully folded around the mandrel to form a capacitor element and trapped; and (h) means for measuring the length of composite strip wound onto the mandrel and for stopping the winding operation when the element is completely wound; the arrangement being such that when the automatic timing means starts it immediately stops the rotation of the mandrel, unclamps the composite strip, removes the means for folding the leading end of the composite strip around the mandrel from its operative position, and then restarts the mandrel and the measuring means.

Claim 4

Apparatus for automatically producing wound capacitor elements from a composite strip comprising (A) a mandrel; (b) a drive for rotatably driving the mandrel; (c) automatic timing means for starting and stopping rotation of the mandrel; (d) means for folding the leading end of the composite strip around the mandrel; (e) a temporary clamp for engaging the composite strip; (f) means for sensing the tension in the length of composite strip between the mandrel and the temporary clamp; (g) means for starting up the automatic timing means when, upon rotation of the mandrel, an increase in tension in said length operates the sensing means as an indication that the leading end of the composite strip has been successfully folded around the mandrel to form a capacitor element and trapped; and (h) means for measuring the length of composite strip wound onto the mandrel and for stopping the winding operation when the element is completely wound; the arrangement being such that when the automatic timing means starts it immediately stops the rotation of the mandrel, unclamps the composite strip, removes the means for folding the leading end of the composite strip around the mandrel from its operative position, and then restarts the mandrel and the measuring means.

Claim 5

Apparatus for automatically producing wound capacitor element from a composite strip comprising (a) a mandrel; (b) a drive for rotatably driving the mandrel; (c) automatic timing means for starting and stopping rotation of the mandrel; (d) a carriage which can be caused to approach or retreat from the plane of the composite strip as it moves onto the mandrel and which can be reciprocated and pivoted between a functional position and a retracted position, which latter position it occupies during the winding operation; (e) means for folding the leading end of the composite strip around the mandrel; (f) a temporary clamp for engaging the composite strip, the means for folding the end of the composite strip on the mandrel and the clamp for the strip being mounted on the carriage; (g) means for sensing the tension in the length of composite strip between the mandrel and the temporary clamp; (h) means for starting up the automatic timing means when, upon rotation of the mandrel, an increase in tension in said length operates the sensing means as an indication that the leading end of the composite strip has been successfully folded around the mandrel and trapped; and (i) means for measuring the length of composite strip wound onto the mandrel to form a capacitor element and for stopping the winding operation when the element is completely wound; the arrangement being such that when the automatic timing means starts it immediately stops the rotation of the mandrel, unclamps the composite strip, removes the means for folding the leading end of the composite strip around the mandrel from its operative position, and then restarts the mandrel and the measuring means.

Claim 6

Apparatus for automatically producing wound capacitor element from a composite strip comprising (a) a mandrel; (b) a drive for rotatably driving the mandrel; (c) automatic timing means for starting and stopping rotation of the mandrel; (d) a carriage which can be caused to approach or retreat from the plane of the composite strip as it moves onto the mandrel and which can be reciprocated and pivoted between a functional position and a retracted position, which latter position it occupies during the winding operation; (e) means for folding the leading end of the composite strip around the mandrel; (f) a temporary clamp for engaging the composite strip, the means for folding the end of the composite strip on the mandrel and the clamp for the strip being mounted on the carriage; (g) means for sensing the tension in the length of composite strip between the mandrel and the temporary clamp; (h) means for starting up the automatic timing means when, upon rotation of the mandrel, an increase in tension in said length operates the sensing means as an indication that the leading end of the composite strip has been successfully folded around the mandrel and trapped; and (i) means for measuring the length of composite strip wound onto the mandrel to form a capacitor element and for stopping the winding operation when the element is completely wound; the arrangement being such that when the automatic timing means starts it immediately stops the rotation of the mandrel, unclamps the composite strip, removes the means for folding the leading end of the composite strip around the mandrel from its operative position, and then restarts the mandrel and the measuring means.

Claim 7

Apparatus as claimed in claim 3, wherein the apparatus includes means for wrapping a covering strip around the wound element.

Claim 8

Apparatus as claimed in claim 4, wherein the carriage also carries means for partially severing the composite strip and the covering strip.

Claim 9

Apparatus as claimed in claim 5, wherein part of the carriage forms a table against which the free end of the composite strip when it is cut may be retained by suction means and against which the composite strip can be held by the clamp.

Claim 10

Apparatus as claimed in claim 4, wherein spindles for carrying pads of film to form the composite strip and for carrying a pad of covering strip project from a side of a vertical support and each spindle has an associated tension monitor for maintaining the tension in the film or strip at a desired value, each tension monitor comprising a spring biased pivoted frame mounted on the vertical support, a guide roller fixed with respect to the frame and a dancer roller mounted on the pivoted frame, the arrangement being such that movement of the pivoted frame in accordance with changes in the tension of the film or strip operates a control device for energizing a brake for the associated spindle.

Claim 11

Apparatus as claimed in claim 7, wherein between the tension monitor associated with the spindle for a pad of covering strip and the mandrel is a further pivoted frame serving as a wrapper arm and carrying rollers about which the strip will travel and a pressure member adapted to press the free end of the covering strip against the surface of the composite strip prior to wrapping of the covering strip about the mandrel.

Claim 12

Apparatus as claimed in claim 7, wherein an arm pivotably mounted on the vertical support carries at its free end heat sealer means, the arm being adapted to pivot when wrapping of the covering strip around the element is completed to cause the heat sealer means to contact the last turn of the covering strip and to seal it to the last preceding turn.

Claim 13

Apparatus as claimed in claim 3, wherein the mandrel comprises a retractable winding spindle adapted to carry a tubular former about which a capacitor element can be wound and wherein tubular formers are fed one by one from a source of supply on to the upper end of a loading arm which is pivoted at its lower end in such a way that it is adapted to fit a former on to the winding spindle as the spindle advances from a retracted position.

Claim 14

Apparatus as claimed in claim 3, wherein the means for folding the leading end of the composite strip around the mandrel comprises a retractable transverse bar operated by mechanism carried by the carriage, the bar being adapted to tuck the free end of the composite strip under the mandrel.

Claim 15

Apparatus as claimed in claim 3, wherein the sensing means comprises a bar that is in contact with the length of composite strip between the mandrel and the clamp during the operation of feeding the end of the strip around the mandrel and is withdrawn into an inoperative position, after it has caused the timing means to start.

Claim 16

Apparatus as claimed in claim 7, wherein a printing unit is provided for printing an identification code on a surface of the covering strip during its passage to the mandrel.

Claim 17

Apparatus as claimed in claim 3, having at least one fluid-operated cylinder controlled by a solenoid valve energized by a cam switch mounted on a cam shaft which forms the timing means of the apparatus, the cam shaft being driven by an electric motor in such a way as to complete one revolution during each winding cycle.