公开(公告)号：US3597955A

公开(公告)日：1971-08-10

申请号：US3597955D

申请日：1969-01-13

Applicant: CYRIL BATH CO

Inventor： MACKENZIE ROBERT A

IPC: B21D22/06 ,  B21D11/04

CPC classification number: B21D22/06

Abstract: An apparatus for stretch drawing sheet metal between complementary male and female dies arranged between two stretch heads which grip opposite margins of the sheet and tension it unidimensionally into its yield range independently of die closure. While maintaining the sheet so tensioned with its lateral margins unconfined, the heads wrap the sheet about the male die prior to closure of the dies. Beginning at the end of the wrapping operation and continuing during final closure of the dies, the gripping pressure exerted by the heads on the gripped margins of the sheet is reduced sufficiently to eliminate the independent tensioning by the heads while holding the sheet steady. The reduction is such as to permit the margins to slip between the gripping jaws of the head under the tensioning force imposed by closure of the dies at some portions along the width of the sheet whereat die configuration requires that additional stock exteriorly of the dies at the ends thereof be drawn or fed in between the dies, while other portions where additional stock is not required are held firmly in place but free from the independent tensioning by the heads. The final drawing by the dies occurs before the sheet can work harden as a result of having been independently tensioned into the yield range.

公开(公告)号：US3299689A

公开(公告)日：1967-01-24

申请号：US36801464

申请日：1964-05-18

Applicant: CYRIL BATH CO

Inventor： DOLNEY STANLEY M ,  MACKENZIE ROBERT A

IPC: B21D25/02

CPC classification number: B21D25/02

公开(公告)号：US3595057A

公开(公告)日：1971-07-27

申请号：US3595057D

申请日：1969-04-15

Applicant: CYRIL BATH CO

Inventor： MACKENZIE ROBERT A

IPC: B21D11/02 ,  B21D25/00 ,  B21D25/02

CPC classification number: B21D25/00 ,  B21D11/02

Abstract: The stretcher comprises a frame with two stretch units mounted thereon for adjustment toward and away from each other for accommodating therebetween selected lengths of sheet or plate stock to be stretched or stretch formed. A male die is supported between the units when stretch forming is to be effected. Each unit comprises a linkage rockable by power means about a horizontal pivot extending transversely of the stock and tensioning dimension, and carries a stock gripping head. Rocking of the linkages causes the heads to swing about their pivots in directions away from each other for stretching the stock and toward the frame for laying the stock onto the die. The stretcher is characterized in that the horizontal pivot is adjustable along a path extending generally upwardly and downwardly normal to the plane of the stock, and the units can be latched securely in adjusted positions along the frame. With these adjustments, a preselected exact amount of total stretch can be imparted to the stock.

公开(公告)号：US3452574A

公开(公告)日：1969-07-01

申请号：US3452574D

申请日：1967-06-29

Applicant: CYRIL BATH CO

Inventor： MACKENZIE ROBERT A

IPC: B21D11/02 ,  B21J11/00

CPC classification number: B21D11/02

公开(公告)号：US3452573A

公开(公告)日：1969-07-01

申请号：US3452573D

申请日：1967-06-14

Applicant: CYRIL BATH CO

Inventor： MACKENZIE ROBERT A

IPC: B21D11/02 ,  B21D11/04 ,  B21D41/02

CPC classification number: B21D11/02

公开(公告)号：US3314269A

公开(公告)日：1967-04-18

申请号：US57548766

申请日：1966-08-12

Applicant: CYRIL BATH CO

Inventor： MACKENZIE ROBERT A

IPC: B21D25/02

CPC classification number: B21D25/02