US2175200A - Trimming machine - Google Patents

Description

Oct. 10, '1 939.

J. T. LANCASTER 5,200 I TRIMMING MACHINE Filed Sept. 25, 1938 2 Sheets-Sheet 1 ,3 //v l/f/V rm.

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Oct. 10, 1939. LANCASTER 2,175,200

TRIMMING MACHINE Filed Sept. 23, 1958 2 Sheets-Sheet 2 /6 Figfi F 5 44 M 17 1g 4/ /8 //\/l E/VTL7R l5 Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE TRIMJVIING MACHINE Application September 23, 1938, Serial No. 231,361

13 Claims.

This invention relates to trimming machines and is herein illustrated in a form designed to facilitate severing a marginal strip constituting the lasting allowance of a lining, a toe-box and a doubler at the toe-end of a partially fabricated shoe without severing the corresponding margin of the outer layer or vamp. This shoemaking operation is commonly performed in the manufacture of womens shoes the toe-ends of which are to be lasted with cement and requirethe lasting allowance of the vamp to lie in contact With the insole when the toe-lasting operation is performed.

The trimming operation under consideration is rendered difficult, particularly when performed with a power-operated machine, by conditions set up in prior operations necessary to advance the shoemaking procedure to that stage at which the toe-lasting operation is next in order. One of these prior operations is that of pulling over the toe-end of the vamp, as a result of which dog-ears or horns are formed in all the layers of the upper at the toe-end thereof. It is diflicult to obtain smooth even trimming of these dog-ears, particularly when the strip to be severed includes, as it commonly does, a comparatively stiff thermoplastic toe-box in which the irregular formations have been developed while the toe-box was in a plastic condition.

Another prior operation (side-lasting) leaves the lasting margins of all the layers of the upper permanently secured to the insole in the region of the tip-line, where the severing of the aforesaid marginal strip should begin and end. The problem of trimming the inner margin without cutting the outer margins is aggravated in this region by relation in which the shoe elements are secured.

As herein illustrated, the present invention provides an improved trimming machine comprising a work-guiding member arranged to be engaged by the margin of the insole, and a power-operated cutting blade formed and arranged to project between the unlasted margin to be severed and the corresponding margin of the vamp or outer layer. The work-guiding member and the cutting blade are provided with co-operative shearing edges both preferably parallel with the line of feeding movement at the cutting locality, and the cutting blade is operated with movements across this line in one direction to separate the outer margin from the inner margin, and in the opposite direction to sever the inner margin with successive shearing cuts.

The invention also provides another marginseparating member thinner than the cutting blade and also formed and arranged to project between the margin to be severed and the corresponding outer margin. This member is also operated with movements in one direction to separate the outer margin from the inner margin initially to facilitate the insertion of the cutting blade between the margins and thereafter to deflect the outer margin so that it may readily run behind the cutting blade. Moreover, the thin margin-separator is resilient, and its work-engaging portion is arranged to co-operate with 'the aforesaid work-guiding member to clamp a narrow band of the inner margin intermittently at points contiguous to the shearing edges. Its clamping action is effective to remove irregular formations from the materials to be severed prior to each cutting action of the movable cutting blade.

These and other features of the invention are illustrated in the drawings and are hereinafter described.

Referring to the drawings:

Fig. 1 is a right side elevation of a trimming machine embodying the present invention and includes a representation in section of the toe portion of a partially fabricated shoe from which a marginal strip is in process of being severed;

Fig. 2 is a view similar to the upper left portion of Fig. 1 except that the movable cutting blade is at a different point in its range of motion;

Fig. 3 is a horizontal section of the structure intersected by line III-III of Fig. 1;

Fig. 4 is a front elevation of the movable cutting blade;

Fig. 5 is a front elevation of a thin resilient sheet-steel member that effects initial separation of the inner and outer margins of a shoeupper and performs additional functions;

Fig. 6 is a right side elevation of the abutment member with which the movable cutting blade co-operates;

Fig. 7 is a sectional plan view of the member shown in Fig. 6; and

Fig. 8 is a top plan View of the forepart and shank of a partially fabricated shoe in an early stage of the trimming operation for which the illustrated machine is intended.

Describing first a typical example of work as represented in Fig. 8, the partially fabricated shoe comprises, as usual, a vamp it, an insole ii, and a lining l2, which may, and usually does, include a doubler and a thermoplastic toe-box. 55

No attempt has been made to represent the doubler and the toe-box individually in the drawings since they are commonly united with the lining l2 by adhesion of the thermoplastic substance with which the toe-box is impregnated, and so far as the operation under consideration is concerned, these three layers form a composite inner margin from which a strip 50 is to be severed along a line adjacent to the perimeter of the toe-end of the insole. In the ordinary routine of pulling over such a shoe, a toe-tack is driven to secure the lasting margin of the vamp and the corresponding inner margin temporarily to the insole at a point where a tackhole I3 is represented. This toe-tack, driven while the toe-box is limp with heat, remains in the hole l3 while the shoe undergoes a side-lasting operation whereby the lasting allowances of both the lining and the outer layer are permanently secured to the insole. Fig. 8 represents the result of the side-lasting operation in which blind staples M are the means for securing the lasting margins to the insole except at the toeend of the shoe where they are omitted, the lines of anchorage terminating in the region of the tip-line. When the making operation has progressed to this stage, the shoe is ready for the trimming operation herein described, except that the toe-tack must be pulled from the hole l3 to release the inner and outer margins loosely enveloping the toe-end of the insole.

The member l5 (Fig. 6) constitutes an'abutment against which a movable cutting blade l6 (Fig. 4) operates to sever a strip 50, and against which the margin to be trimmed is intermittently pressed by a clamping blade 40. The member l5 has a fiat face I! to be engaged by the margin of an insole, and a downwardly projecting lip H? to guide the work by engagement with the lining andthe perimeter of the insole. It also has a shearing edge I8 with which the blade l6 co-operates to sever the strip 50. The shank portion of the member 15 is provided with a small horizontal bore 20 near its upper end to receive a pivot-pin 2| (Fig. 1) by which it may be attached to an overhanging portion of the frame 22. As shown in Fig. 3, the member 15 is flanked by two confronting cheeks of the frame and is thereby braced against the sidewise stresses. These cheeks are connected by a web 23 that lies behind the member [5 and provides a rigid abutment against which the member may be secured by the heads of two screws 24 screwed into the cheeks respectively. When the screws are set up tightly, the member 5 is rigidly braced against stresses in every direction but when the screws are removed, the member l5 may be swung forwardly and upwardly about its pivot-pin 2| to facilitate access to other elements hereinafter described. v

The butt-end of the cutting blade 16 is arranged in a groove between confronting cheeks formed on an oscillatory holder 25 and is adjustably secured to the holder by a clamping screw 26. The checks of the holder brace the cutting blade rigidly against s'idewis'e stresses, but the blade is adjustable up and down within the range of an elliptical hole 2'! (Fig. 4) through which the screw extends. This provision for adjustment is to locate the lower end of the cutting blade in co-operative shearing relation to the shearing edge l8 of the fixed member IS, the cutting blade having a cutting edge 28 parallel to the edge l8 that moves to and fro across the latter. The holder 25 is arranged between the cheeks of the frame 22 and is mounted on a pivot-pin 29. The axis of this pivot-pin is parallel to the shearing edges l8 and 28 and is located in a plane normal to the shearing plane at the cutting locality. Rapid oscillatory motion is imparted to the cutting blade by mechanism comprising a powerdriven shaft 39, an eccentric 3| carried thereby, an eccentric strap 32, a connecting rod 33, and a pivot-pin 34 by which the forward end of the rod 33 is connected to an arm of the holder 25. A pulley 35 is secured to the shaft 3!! to be driven by a belt (not shown). The rod 33 and the strap 32 have screw connection that provides for locating the range of travel of the cutting edge 28.

Once the lower end of the cutting blade l6 has been inserted between the margin of the vamp l0 and the margin to be severed, its back-strokes are eifective to separate the margin first mentioned from that to be severed, but since these margins are maintained nearly, if not quite, in contact with each other at points A and B (Fig. 8), some initial separation of the margins should be effected to facilitate the insertion of the cutting blade between them at either of these points. Accordingly, the invention provides a relatively thin blade 46 that projects beyond the cutting end of the blade l5 and beyond both sides thereof not only to effect initial separation of the margins but also to perform other functions to be described. This thin blade 40 is preferably U-shaped as shown in Fig. 5, the space 4| between its arms being of approximately the same shape as the cutting blade but very slightly wider to provide clearance, since in operation, the cutting edge 28 moves to and fro through this space and beyond the bridge portion 42 by which the arms are connected.

The bridge portion 42 may be used initially to separate the inner and outer margins of the work far enough to enable the cutting blade to be inserted between them, but thereafter the portion 42 co-operates with the lip IQ of the member l5 to straighten irregular formations in the materials to be trimmed. In the performance of the latter function, the portion 42 and the member I5 alternately clamp and release the materials to be trimmed in a band below but contiguous to the shearing edges. The clamping surfaces of the elements 42 and [5 are normal to the plane of the shearing cut and they set up the clamped materials accordingly. When the parts are assembled in their intended relations, the upper edge 43 of the bridge portion 42 underlies and barely clears the lower end of the cutting blade. The extremities of the two arms of the blade 40 are provided with holes 44 to receive screws 45 by which this member is secured to the blade-holder 25. Preferably, a narrow kerf is formed in the holder to receive the anchoring portions of the arms, and when the screws 45 are set up tightly, they clamp the arms in addition to furnishing positive anchorage for them. The member 40 is made of resilient sheet metal such as spring steel to provide a factor of flexibility and to insure a considerable pressure of the portion 42 against the clamped margin prior to and during the actual cutting in each cutting stroke of the blade I6.

The arms of the clamping member 40 have a slight initial curvature represented in Fig. 2 in which figure they have placed the lower portion 42 against the materials to be trimmed but have not been deflected thereby. This figure represents the blade-holder 25 about midway between the limits of its range of oscillation, and

it may be assumed that the cutting blade is moving toward the fixed shearing member. Consequently, the first half of each cutting stroke is effective to straighten crooked or curved portions of the materials to be severed. The third quarter of the stroke is effective to develop clamping pressure by which the materials are securely held, and the final quarter is effective to force the cutting edge 28 through the materials to the terminal limit of the stroke represented in Fig. 1. The materials to be severed are therefore firmly clamped between the portion 42 and the lip l9 prior to and during the actual cutting and thereafter until the movable cutting blade has been retracted about half Way in its back strike. During the latter half of the back stroke, the clamping portion 42 is retracted from the lip I9 to release the materials and at this point the work may be fed manually to place an uncut portion of the inner margin between the shearing edges.

In practice, the shaft 30 may be driven at a speed of about 800 R. P. M. at which speed the individual cuts and the alternate clamping and releasing actions will occur so rapidly that the feeding of the work will not be appreciably interrupted, nor will the trimming lack continuity, since the shearing edges have suflicient length to join the individual cuts.

The dog-ears hereinbefore mentioned are represented at 5| in Fig. 8. Since theseirregular formations usually include a comparatively hard and. stiff thermoplastic substance and are usually developed while that substance is in a plastic condition incidentally to pulling over the toe-end of the upper materials, they would seriously obstruct feeding movement of the shoe and would cause ragged or uneven cutting were it not for the straightening and clamping effect of the elements 42 and I9 adjacent to the cutting locality. As the work advances, the irregular formations in the materials to be severed are straightened little by little and the reformed materials are set up in an erect position before reaching the cutting locality.

Since the work-engaging elements are symmetrical as viewed from above and from the front, and since the shearing edges are both parallel to the line of feed, the work may be fed from right to left or from left to right with equally satisfactory trimming results, and the trimming operator may feed it in whichever direction he prefers. For example, referring to Fig. 8, the trimming may begin at point A and be terminated at point B, in which case the initial feeding movement will be in the direction indicated by an arrow. On the other hand, the trimming may begin at point B and be terminated at point A, in which case the shoe will be presented initially at an angle the opposite of that represented in Fig. 8 and the direction of the feeding movement will be the reverse of that indicated. Again, the trimming may begin at an intermediate point where the inner and outer margins are not closely confined and may prograss in either direction from that point to one of the terminal points, after which the final stage of trimming may also start at an intermediate point and progress in the opposite direction to the other terminal point. The latter procedure has this advantage: It avoids the difficulty of inserting the blades between the margins near the points where the latter are secured to the insole.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is: I

' 1. A trimming machine comprising a movable cutting blade formed and arranged to project between loose lasting margins of an outer layer and an inner layer of upper materials of a partially fabricated shoe, an abutment member arranged to be engaged by the inner surface of said inner margin, said blade and said member having co-operative shearing edges arranged to sever amarginal strip of said inner margin in a plane intersecting said outer margin without severing the latter, and power-driven means arranged to'operate said blade with cutting movements toward said member and with movements away from that member to displace said outer margin from said inner margin.

2. A trimming machine as defined in claim 1 in which said movable blade is arranged to oscillate about an axis parallel with one of said shearing edges.

3. A trimming machine as defined in claim 1 in which said abutment member is provided with a lip adjacent to its shearing edge to be engaged by the perimeter of the insole.

4. A trimming machine comprising a thin member formed and arranged to project between loose lasting margins of an outer layer and an inner layer of upper materials of a partially fabricated shoe to effect initial separation of said margins. two shearing members having co-operative cutting edges arranged to sever a marginal strip of said inner margin in a plane intersecting said outer margin without severing the latter, one of said shearing members being formed and arranged to project between said margins adjacent to said thin member, power-driven means arranged to operate one of said shearing members with movements toward and from the other, and power-driven means by which said thin member is reciprocated with short strokes against said outer margin to displace it from said inner margin.

5. A trimming machine comprising a thin member formed and arranged to project between loose lasting margins of an outer layer and an inner layer of upper materials of a partially fabricated shoe to effect initial separation of said margins, two shearing members having co-operative cutting edges arranged to sever a marginal strip of said inner margin in a plane intersecting said outer margin without severing the latter, one of said shearing members being formed and arranged to project between said margins adjacent to said thin member, and power-driven means arranged to operate the shearing member last mentioned with movements toward and from the other said shearing member.

6. A trimming machine as defined in claim 4 in which the shearing member that projects between said margins is operated with movements away from said outer margin to sever the inner margin and with movements away from the latter to deflect the outer margin,

'7. A trimming machine as defined in claim 4 in which the movable shearing member and the thin separator are operated in synchronized relation by a reciprocatory actuator common to both.

8. A trimming machine comprising two shearing members having co-operative cutting edges arranged to sever a marginal strip of a loose inner margin of upper materials of a partially fabricated shoe in a plane intersecting a loose outer margin without severing the latter, and power-driven means arranged to operate one of said members with movements toward and from the other, said cutting edges being arranged to cut with the same severing effect when the work is fed in one direction in the shearing plane as when fed in the opposite direction.

9. A trimming machine comprising poweroperated means including a reciprocatory cutting blade formed and arranged to project between an outer margin and an inner margin of unlasted upper materials of a partially fabricated shoe, and an abutment member having a surface to be engaged by the margin of the insole and a shearing edge to be engaged by said inner margin close to the insole, and said blade having a cutting edge in shearing relation to the edge first mentioned, said edges being arranged to cut with the same severing efiect when the work is fed in one direction in the shearing plane as when fed in the opposite direction.

10. A trimming machine comprising poweroperated means including a reciprocatory holder, a cutting blade and a resilient work-clamping member, said blade and said member both being carried by said holder and arranged to project between two confronting layers of a work-piece, and an abutment member arranged to brace one of said layers against the cutting action of said blade and the clamping action of said clamping member, said abutment member and said cutting blade having co-operative shearing edges arranged to sever the layer so braced in a line contiguous to a work-clamping edge of said clamping member.

11. A trimming machine as defined in claim 10 in which said shearing edges are arranged to cut with the same severing effect when the work is fed in one direction in the shearing plane as when fed in the opposite direction.

12. A trimming machine comprising poweroperated means including a reciprocatory holder and a resilient work-clamping blade secured thereto and projecting therefrom, an abutment arranged to co-operate with a face of said blade near its outboard end to clamp intermittently the material to be trimmed, said blade having an opening and said abutment member having a shearing edge in register with said opening, and a cutting'blade afiixed to said holder, an extremity of said cutting blade being formed and arranged to move laterally to and fro through said opening and having a cutting edge in shearing relation to said shearing edge of said abutment member.

13. A trimming machine comprising an abutment having a lip and a face to be engaged respectively by the perimeter and the margin of the insole of a partially fabricated shoe, and power-operated means including a cutting blade, a resilient clamping blade, and a reciprocatory holder by which both of said blades are carried, said cutting blade and said abutment having cooperative shearing edges arranged to sever with successive cuts a strip of a loose lasting margin .of the shoe-upper, and said resilient blade being arranged to clamp a portion of said margin intermittently against said lip.

JOHN T. LANCASTER.

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