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US 4,282,736 AGranted
Stock lifter
AssigneeBlue Ridge Industrial Technologies, Inc.
InventorHarry G. Mashburn
Life of this patent
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AssigneeBlue Ridge Industrial Technologies, Inc.
InventorHarry G. Mashburn
Estimating the term…
A stock lifter for supporting and guiding strip stock materials during progressive die operations, and wherein the stock lifter has an annular groove adjacent its upper free end for supportingly receiving and guiding strip stock material. Shoulder means is provided along the body of the stock lifter for engagement of a hold-down fastener means therewith in mounting the stock lifter in a supporting die. The annular nature of the groove of the stock lifter permits the stock lifter to be installed with a hold-down fastener located at any point around the periphery of the stock lifter, thus allowing the supporting die member to be formed of reduced width and therefore a savings of material and attendant costs.
A stock lifter for use in pairs and at opposite edge portions of strip stock material for supporting and guiding such stock material from one pair of relatively movable opposing die members to another pair and for moving such stock material out of engagement with die members during separation of the die members following successive die operations on such stock material, said stock lifter being characterized as being capable of being positioned in any desired orientation in a supporting die member thereby effectively serving to reduce the amount of material required for the formation of such supporting die member, said stock lifter comprising
A stock lifter for use in pairs and at opposite edge portions of strip stock material for supporting and guiding such stock material from one pair of relatively movable opposing die members to another pair and for moving such stock material out of engagement with die members during separation of the die members following successive die operations on such stock material, said stock lifter being characterized as being capable of being positioned in any desired orientation in a supporting die member thereby effectively serving to reduce the amount of material required for the formation of such supporting die member, said stock lifter comprising
A stock lifter for use in pairs and at opposite edge portions of strip stock material for supporting and guiding such stock material from one pair of relatively movable opposing die members to another pair and for moving such stock material out of engagement with die members during separation of the die members following successive die operations on such stock material, said stock lifter being characterized as being capable of being positioned in any desired orientation in a supporting die member thereby effectively serving to reduce the amount of material required for the formation of such supporting die member, said stock lifter comprising
A stock lifter for use in pairs and at opposite edge portions of strip stock material for supporting and guiding such stock material from one pair of relatively movable opposing die members to another pair and for moving such stock material out of engagement with die members during separation of the die members following successive die operations on such stock material, said stock lifter being characterized as being capable of being positioned in any desired orientation in a supporting die member thereby effectively serving to reduce the amount of material required for the formation of such supporting die member, said stock lifter comprising
Dependencies are inferred from the claim text.
No related US applications are recorded in the indexed filing history.
Drawings are temporarily unavailable. Open the PDF at USPTO
Control or correction devices in association with moving strips: centering devices, e.g. edge guiding
Working or processing of sheet metal or metal tubes, rods or profiles
Term ended 13 Mar 2000 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates to stock lifters for supporting and guiding strip stock material during progressive movement of such material from one pair of opposing die members to another pair.
Stock lifters previously have been provided arranged in pairs and spaced from one another along a row of progressive dies with lifters of each pair located at opposite side edges of a strip of sheet stock material upon which die operations were performed. There have also been provided transverse grooves near the outer or free ends and in adjacent sides of the lifters of each pair into which grooves the opposite edge portions of the strip stock material have extended for slidably supporting and guiding the strip stock material as it has progressively advanced to and from the different dies. As shown in U.S. Pat. No. 2,979,004 to Kenville, et al., these grooves have been slightly curved and extended across about the half of the periphery of the lifter that faced inwardly toward the strip stock material, and such grooves have been beveled at their edges apparently to aid in the receipt and guiding of progressive strip stock material.
These lifters have had their inner or lower end portions slidably supported in the lower die members for limited longitudinal movement in a vertical direction whereat they have been engaged by the upper die members during downward movement of the upper die members and thereby have lowered the strip stock material onto the lower supporting die members for punching, forming or other desired die operations. Springs have been located in recesses in the lower die members under the lifters which have been compressed during the lowering of the upper die members and which have then urged the lifters outward and such strip stock material upward upon the return of the upper die members to their upward inactive positions. The raising of the strip stock material has disengaged the same from the lower die members and positioned same above the parts of the lower die members so as to provide clearance for advancement of the stock material along the row of progressive dies.
Some of the objects and features of this invention having been stated, others will become more apparent as the description proceeds, when taken in connection with the accompanying drawings, in which:
FIG. 1 is a perspective view in environmental setting illustrating a preferred embodiment of stock lifters in accordance with the invention installed in a supporting die member;
FIG. 2 is a partial sectional view along the line 2--2 of FIG. 1;
Referring now to the drawings, which illustrate particular embodiments of the invention, FIGS. 1 through 4 show a stock lifter 10 in accordance with the invention in use in a die assembly comprising spaced pairs of opposing lower and upper die members, 21 and 22 respectively, wherein a length of strip stock material 30 is being directed between said die members for die component action while being supported and guided by the stock lifters 10.
Although only one pair of die members is shown in FIG. 3, any number of sets may be employed and they may consist of a combination of stamping, forming, and punching dies for performing progressive operations on the stock material. Articles while being produced with an assortment of dies of this character remain a part of the strip stock material until they have arrived at the desired stage, where they are then separated from each other and the remainder or waste stock material, it being necessary to keep the partially completed articles connected together so as to control their movements and positions relative to the different sets of dies with a single feeding operation. This manner of die operation requires the raising and lowering of the strip stock material between each operation of the dies on the strip stock material because of the necessity of having all depressed portions formed on said strip stock material by said dies horizontally above all parts of the lower die members while effecting feeding operations. It is mainly for the purpose of raising and lowering and thereby supporting the strip stock material that a plurality of stock lifters positioned at opposite edges of the strip stock material are employed. Stock lifters also function as guides in slidably supporting the strip stock material against lateral movement, as well as strippers for disengaging the stock material from the dies.
Referring now particularly to FIG. 4, the embodiment of the stock lifter 10 shown there is comprised of a basically cylindrical-like elongate body 11 which has at its upper or outer free end an annular head 12. As will be understood from viewing FIGS. 1 to 3 collectively, during die operation the annular head 12 is contacted by the upper die member 22. Adjacent to and below the head is an annular groove 13 that extends around the entire circumference of the body 11, such groove being provided to receive and thereby support and guide strip stock material 30 during the die operations. Unlike prior stock lifters which utilized a segmental groove extending across only about one-half of the periphery of the lifter and wherein stock edge contact was only intended to occur at a single predetermined point within the segmental groove, such contact may occur in this invention at any desired point around the circumference of the annular groove 13. This insures proper stock material contact with the lifter even if the stock material is not perfectly fed into the annular groove. Thereby being tolerant to feed imperfections, the circumferential annular groove 13 of the invention may be of the same width throughout as shown and have substantially square or right-angled exterior edges 14 without the necessity of rounded or beveled edge corners as appear on prior stock lifters which beveled edges were heretofore provided to allow for some tolerance for the otherwise exacting stock material contacting relationship. Aside from the advantage of not having to perform the additional machining step of beveling, right-angled edges 14 by extending essentially to the full diameters of the head 12 and body 11, provide maximum stock bearing contact surface area, while maintaining the inner diameter of the groove 13 sufficiently large enough to insure the structural integrity of the head 12 and the annular groove 13.