US2108178A - Apparatus for trimming or pinking leather or the like - Google Patents

Description

Feb. 15, 1938. s. E. ROSENBERG 2,108,178

APPARATUS FOR TRIMMING OR PINKING LEATHER OR THE LIKE Filed Feb. 24,. 1936' 2 Sheets-Shee't 1 m", m ']izwW Fb. 15, 1938. s. E. ROSENBERG APPARATUS FOR TRIMMING OR PINKING LEATHER OR THE LIKE 2 Sheets- 311691 2 Filed Feb. 24, l956 Patented Feb. 15, 1938 UNITED STATES APPARATUS FOR TRIMIVHNG OR PINKING LEATHER OR THE LIKE Stig E. Rosenberg, Brockton, Mass.

Application February 24, 1936, Serial No. 65,200

4 Claims.

This invention relates to a method of and apparatus for trimming marginal portions of a piece of leather or the like, the trimming or pinking cuts being such as to leave a beveled edge.

It is an object of the invention to provide apparatus for cutting a non-straight marginal portion of a piece of leather, such as a part for a shoe upper, so that the entire portion to be trimmed is operated upon with one stroke only. It is another object of the invention to provide apparatus by which a non-straight marginal portion of a piece of leather may be pinked on a bevel in such a manner that each of the scallops along the edge projects in a direction perpendicular to the direction of the edge at that point.

Various other advantageous features of the in.- vention will be apparent to one skilled in the art from a disclosure thereof in the description of certain embodiments which follows, and on the drawings of which Figure 1 is a plan view of apparatus embodying the invention, designed for pinking a shoe vamp.

Figure 2 is a side elevation of the same, a portion being broken away to show in section.

Figure 3 is a section on the line 33 of Figure 1, this view being. on a larger scale.

Figure 4 is a fragmentary portion of Figure 3 showing the parts in a different position of operation.

Figure 5 is similar to Figure 4, showing a further step in the operation of the apparatus.

Figure 6 is similar to Figure 4 except that a backing sheet is shown in addition.

Figure 7 is a fragmentary perspective view of a marginal portion of a piece of leather or similar sheet material after being operated upon according to the invention.

Figure 8 is a fragmentary sectional view of apparatus for bevel-trimming leather or the like.

Figure 9 is a perspective view of a shoe vamp having edge portions thereof bevel-trimmed.

Figure 10 is a fragmentary View of apparatus for bevel-trimming a piece of leather.

Figure 11 is a fragmentary perspective view of a piece-of leather having an edge portion trimmed on a bevel.

Referring to the drawings in detail, a die suitable for carrying out the invention is illustrated in Figures 1 and 2. As illustrated, this die may consist of a base block on which is mounted a stationary supporting plate or table 22, the supporting plate having a beveled edge (Cl. M l-23 portion 23 which is shaped to conform to the contour of the portion of the work which is to be trimmed or pinked. By way of example, a shoe vamp 25 is shown as the work which is to be pinked. As illustrated in Figure 1, the vamp 25 is of the well known wing-tip shape, the upper or inner edge of which is to be pinked prior to being sewed to other portions of the upper. Mounted at suitable points on the base block 20 are gage pins 28. The pinking cutter is in the form of a knife having a sharp cutting edge following the configuration of the bevel edge 23 of the supporting plate 22, the knife as shown being integral with a horizontal back 3| which rigidly maintains the blade 30 in its shape.

As indicated in Figures 2 and 3, the pinking knife 30 has a blade of uniform width (or height) and of substantial thickness sufficient for the formation of a zigzag cutting edge by V notches or grooves in the side faces of the blade, the surface defined by the cutting edge having a substantially uniform bevel and being complemental to the surface 23 of the work-supporting table 22.

As indicated in Figures 3 to 6, the knife 30 has a beveled cutting edge 32 conforming to the bevel of the plate edge 23, so that, when the knife descends in a cutting operation, the entire cutting edge simultaneously engages the bevel edge 23 of the supporting plate. As shown, the knife may be secured to the under face of a suitable plate 34 which in turn is mounted on a plurality of pillars 36, the pillars extending into suitable cavities 38 in the block 28 and being pressed upwardly by springs 41? in the cavities 38, as indicated in Figure 2. The plate 34 and the knife back 3! are provided with suitable apertures 42 and 43 respectively, above the gage pins 28 so as to permit the operator to see the pins and the marginal portions of the work immediately in contact therewith before the knife descends. The operation of the pinking mechanism is indicated in Figures 4 and 5. In using the apparatus, the operator places a vamp or other piece of work on the supporting plate 22 and pushes it until it engages the several gage pins 28, sighting the gage pins through the apertures 42 and 43 to see that all are engaged by the work. Since the bevel edge 23 conforms to the marginal portion of the vamp to be pinked, this marginal portion overhangs the bevel edge 23 as indicated at 46 in Figure 3. The plate 34 with the knife 3!! is then caused to descend by any suitable means so that the knife 30 engages the overhanging portion 4.6 of the work. This overhanging portion is thus pushed down out of the plane of the work, as indicated in Figure 4, so that all portions of the marginal part to be pinked are at an angle to the plane of the work. Further descent of the knife 30 causes the cutting edge to penetrate through the bent marginal portion 46, as indicated in Figure 5. It is evident from this figure that the knife 30 cuts the leather at an acute angle to the surface thereof, thus making a bevel cut. In pinking a marginal portion of a vamp or other part of a shoe upper, it is desirable that each of the scallops or serrations along the edge project in a direction perpendicular to the edge of the leather at that point, that is, in the direction of the radius of curvature of the edge at such point. To this end the pinking knife 36 may be constructed as indicated in Figure 1 so that the scallops, serrations, or other individual projections along the edge will extend in the proper directions, as indicated in Figure '7, wherein are shown a series of serrations 58 arranged along a curved edge, each of the serrations extending in the direction of the radius of curvature of the edge at that point. r

The supporting plate 22 is preferably of some relatively soft metal such as brass or aluminum, so that, if the knife 30 cuts into the face of the bevel edge 23 slightly, the cutting edge of the knife will not be injured. In some cases, it may be desirable to provide a backing layer to overlie the supporting plate 22 and to receive the cutting edge of the knife after it has penetrated through the marginal portion 46 of the leather or other piece of material to be trimmed or pinked. Such a backing layer is indicated at 50 in Figure 6. It may be made of any suitable material such as a fibrous sheet having sufficient elasticity to give properly without cracking or buckling along the marginal portion when the margin is bent down as indicated at 52.

Figure 9 illustrates a shoe vamp having an edge portion 56 cut on a bevel. As shown, this shoe vamp may also have decorative perforations 58 with beveled edges, the perforations having preferably been previously punched as at 68 before the edges thereof are trimmed. The beveled edges may be cut by means of a die similar to that illustrated in Figures 1 and 2 except that the knife 62 has a shape suitable for the desired bevel out instead of being provided with scallops or a zig-zag edge as shown in Figure 1.

Figure 10 illustrates a support plate 10 having a relatively steep beveled edge 12. A knife 14 is mounted in the manner indicated in Figures 1 and 2 so as to push the marginal portion 46 of a piece of leather out of the plane of the piece and against the bevel surface 12. The knife then descends to make a bevel cut on the marginal portion of the leather at a relatively small angle with the face of the leather, such a out being somewhat similar to a skiving cut, as indicated at 16 in Figure 11.

It is evident that various modifications and changes may be made in the invention as herein shown and described without departing from the spirit or scope thereof as defined in the following claims.

1. A pinking die comprising a horizontal supporting table for a piece of leather, said table having a beveled edge portion similar in contour to the edge portion of the leather to be trimmed, gage pins engageable by said edge portion of the leather, means supporting said gage pins adjacent to said beveled edge portion of said table, a knife-supporting plate yieldingly mounted over said table, a knife mounted on the under side of said plate, and means guiding said plate so that downward movement thereof brings said knife into contact with said beveled edge of the table, said plate having apertures therethrough above said gage pins to permit sighting of said pins and the portions of the work adjacent thereto.

2. A die for bevel-trimming or pinking leather or the like, comprising a base, a wor supporti ng table secured on said base, said table having a beveled edge portion, a knife-supporting plate mounted above and resiliently supported by said base, and a knife secured to and projecting down from said supporting plate, the cutting edge of the knife having a shape corresponding to the shape of said beveled edge portion of said table.

3. A die for bevel-trimming or pinking leather or the like, comprising a base, a work-supporting table secured on said base, said table having a beveled edge portion, a plurality of gage pins mounted on said base adjacent to said beveled edge portion, a knife-supporting plate mounted above and resiliently supported by said base, said plate being provided with sighting apertures above said gage pins, and a knife secured to and projecting down from said supporting plate, the cutting edge of said knife having a shape corresponding to the shape of said beveled edge portion of said table.

4. A pinking knife for bevel-pinking shoe upper parts, said knife comprising a blade of uniform width and substantial thickness shaped to correspond to the edge of the work to be pinked, the upper and lower edges of said blade being disposed respectively in parallel horizontal planes when the knife is in use, said lower edge being formed with a zigzag cutting edge defining a bevel surface at a constant angle to the vertical throughout the length of the knife.

STIG E. ROSENBERG.

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