Press machine with means to adjust punching force

A press machine comprising a plurality of press units, each press unit having a die opening and cooperating upper and lower punches being slidable into an extended, inward position in the die opening,

• means for advancing each press unit successively into a punching position where the upper and lower punches are positioned in the extended, inward position in the die opening for pressing material into a compact body,
• guide cam means acting on said upper and lower punches for directing successive upper and lower punches into the die opening, said guide cam means including upper and lower inclined cam surfaces positioned adjacent the punching position for guiding respective upper and lower punches into the extended, inward position within the die opening, and a substantially flat cam surface extending from each of said inclined cam surfaces to the punching position for engaging and maintaining said punches in an extended, inward position as said punches approach said punching position,
• force generating means at said punching position for exerting a punching force onto upper and lower punches advanced into said punching position,
• means for comparing the displacement of said upper and lower punches when said punching force is applied with the undisplaced position of said punches advanced along said flat cam surfaces, and
• control means operatively connected to said force generating means and said comparing means for adjusting the punching force applied onto said punches in response to the compared displacements and predetermined values therefor.

A press machine comprising a plurality of press units, each press unit having a die opening and cooperating upper and lower punches being slidable into an extended, inward position in the die opening,

• means for advancing each press unit successively into a punching position where the upper and lower punches are positioned in the extended, inward position in the die opening for pressing material into a compact body,
• guide cam means acting on said upper and lower punches for directing successive sets of upper and lower punches into the die opening, said guide cam means including upper and lower inclined cam surfaces positioned adjacent the punching position for guiding respective upper and lower punches into the extended, inward position, a substantially flat cam surface extending from each of said inclined cam surfaces to the punching position for engaging and maintaining said punches in an extended, inward position as said punches approach said punching position,
• spaced-apart upper and lower rollers positioned at the punching position for engaging respective upper and lower punches advanced into the punching position,
• force generating means connected to each roll for exerting a punching force onto upper and lower punches advanced into the punching position,
• a transducer connected to each roll for emitting signals indicative of the displacement of the rolls and punches when a punching force is applied,
• first sensor means positioned adjacent said flat cam surface for generating a signal indicative of the advancement of punches thereon,
• second sensor means positioned at said punching position for generating a signal indicative of the advancement of punches into said punching position, and
• means connected to said sensor means and transducers for receiving signals from said sensor means and for receiving said transducer signals indicative of the displacement of the roll and punch,
• means for comparing the received transducer signals indicative of the displacement of upper and lower punches at said punching position, and
• control means operatively connected to said force generating means and said comparing means for adjusting the punching force applied onto said punches in response to the compared displacements and predetermined values therefor.