US2236604A - Method of and machine for folding - Google Patents

Description

April 1, 1941. A. E ALL 2,236,604

METHOD OF AND MACHINE FOR FOLDING Filed Dec. 22 1939 Patented Apr. 1, 1941 lVIETHOD OF AND MACHINE non FOLDING Carl A. Newhall, Peabody, Mass., assignor to United Shoe Machinery Corporation, Borough of Flemington, N. J., a corporation of New Jersey 7 Application December 22, 1939, Serial No. 310,566

6 Claims.

This invention relates to methods of and ma-- chines for folding flexible work pieces such as the margins of parts of shoe uppers.

In a well-known form of folding machine such as that illustrated by Letters Patent of the United. 'Q'

States No. 2,147,749, granted February 21, 1939, f

on an application of H. B. Miller, the work being folded is intermittently fed over a work table by a cooperatinghammer and anvil which also,

act to press a previously formed fold in a portion. of the margin thereof. The fold is formed in the margin of the work before reaching the hammer and anvil by a folding finger and a cooperating creaser foot, the folding finger reciprocating across the path of movement of the Work and folding the margin against the adjacent surface of the creaser foot. During this time the work is held on the work table by a clamping member known as a release leverwhich is movable above the surface of the work table and acts to clamp the work against the bottom of the creaser foot. The work is so held during initial movement of the hammer toward the anvil to press the fold, and the release lever subsequently moves downwardly away from the creaser foot to permit feeding of the work by the hammer and anvil.

The hammer presses a portion of the margin which lies immediately adjacent to the folding finger and which has been pre-folded thereby. The upstanding portion of the margin held between the folding finger and the creaser foot resists pressing of the adjacent portion by the hammer. On the other hand, the portion of the work further from the folding finger and adjacent to the portion which has previously been pressed offers no resistance to the action of the hammer. Thus there is a maximum resistance to the pressing of the material by the hammer adjacent to the folding finger, and this resistance decreases as the distance from the folding finger increases. Therefore, as the folded portion of the work is pressed by the hammer, distortion of the material takes place because of the unequal resistance offered by the material along the face 'of the hammer. This distortion of the material as it is pressed results in the formation of stresses in the folded margin of the work which causes curling or twisting of the work after the completion of the folding operation. This tendency for the work to curl and twist as a result of the stresses set up by the distortion of the material along the edge thereof may be quite noticeable when work pieces of narrow widths, such as straps, are being folded. j

It is an object of the present invention to propoints along the length of the hammer.

vide a new and improved method of and machine for folding the margins of work pieces of flexible material in such a manner that no appreciable tendency to twist is imparted thereto. To this end and as a feature of the present invention, the work being folded is manipulated so as substantially to eliminate distortion of the material as the fold is pressed by the hammer. This is accomplished in accordance with the illustrated embodiment of the invention by bending the portion of the work which is to underlie the fold in I 'a direction opposite to that in which the margin is folded.

By bending the portion of the work which is to underlie the fold in the direction opposite to that in which the fold is formed by the folding finger, the resistance to pressing of the material by the hammer at the portion which lies adjacent to the folding finger where the margin of the material is held in an upstanding position will be greatly reduced and the resistance to the pressing of the material will be substantially the same at all Accordingly, there will be little orno distortion of the material as it is pressed by the hammer and the tendency for the completely folded material to curl or twist. will be substantially eliminated regardless of the width of the work.

This and other features of the present invention will now be described in detail in the specification and illustrated in the accompanying drawi in which,

Fig. 1 is a frontelevation of the head of one form of a machine embodying the principles of the present invention;

Fig. 2 is a perspective view of a portion of the machine shown in Fig. 1 illustrating on a larger scale the operating parts of the machine carried by the lower supporting arm;

Fig. 3 is aview partly in section of a portion of the machine. shown in Fig, 1 with a pieceof work in position to be folded by the folding finger, this view being taken from the rear of Fig. 1

or in-a direction looking toward the observer; and

Fig. 4 is a sectional view of a portion of the apparatus illustrating the position of the work piece after it has been folded by the folding finger. v

Mounted on the outer end of a lower supporting arm I0 attached to the frame of the machine is a work table l2 for supporting the work, the margin of which is to be folded. Adjacent to the work table l2 and also supported by the arm in is a gage block 14 having an upturned plow surface J6 for deflecting the margin of the work rier 24 which is arranged for swinging movement about pivots 26 in arms 28 of a bracket having a hollow cylindrical shank portion 30 carried by an upper supporting arm 32 of the machine. A release lever 34 cooperates with the lower surfaceof the creaser foot 20 to'hold'the work thereagainst while the margin is being folded by the folding finger l8. This release lever is reciprocated vertically by mechanism in the arm I0 so as to relieve the pressure against the lower surface of the creaser foot 20 to permit intermittent feeding of the work over the work table. A gage fnger 36 cooperates with the gage block l4 adjustably to determine the width of fold to be formed in the margin of the work. This gage finger is pivoted at 38 in the lower ends of the bracket arms 28 and the portion adjacent to the gage block [4 is urged downwardly by means of a tension spring (ii! acting on the rearward portion thereof. terminates in a finger piece 42 which cooperates with an adjustable stop screw 44 for limiting the pivotal movement of the finger 36 by the spring 40. A knife 46, operable at the will of the operator by mechanism of the type illustrated in Letters Patent of the United States No. 1,702,598, granted February 19, 1929, on an application of P. R. Glass, is provided for snipping the margin of the work to facilitate folding a curved portion thereof.

The mechanism for feeding the work over the work table and for pressing the fold formed by the folding finger 18 consists of an anvil 50 and a cooperating hammer -52. After a portion of the margin of the work has been folded by the folding finger, the hammer 52 moves downwardly to press the fold against the adjacent portion of the body of the work piece and the hammer and anvil then move rearwardly to feed the work piece a short distance across the work table. While this feeding movement takes place, the release lever 34 is in its lowermost position so that the work piece is not pressed against the lower surface of the creaser foot 20.. As the hammer presses the portion ofthe margin which has greatest adjacent to the folding finger and decreases as the distance therefrom increases. Be-- cause of this unequal resistance offered by the material to the pressing action of the hammer, distortion of the material takes place as the fold is pressed. This distortion of the material results in the formation of stresses along the margin of the work causing curling or twisting thereof after the completion of the foldingoperation.

In order to counteract this tendencyfor the material in the foldto be distorted, the top sur- The rearward end of the gage finger 530 face of the work table [2 is curved upwardly as indicated at 60. This inclined portion of the work table I2 starts at a point adjacent to the release lever 34 and rises abruptly to the anvil 5B. The top surface of the anvil 50 slopes downwardly from the raised portion 60 of the work table [2 so that a downward bend may be imparted to the work piece as it passes over the anvil as' indicated clearly in Fig. 4. As the body of the work piece is bent downwardly or in a direction opposite to that in which the fold is formed by the folding finger during the pressing of the fold by the hammer 52, the resistance to A the pressing of the fold thereby at the portion which lies adjacent to the folding finger where the margin of the material is held in an upstanding position will be greatly reduced. The resistance to the pressing of the material will, therefore, be more nearly the same at all points along the length of the hammer. Accordingly, little or no distortion of the material results from the pressing of the fold by the hammer so that the tendency for the completely folded material to curl or twist will be substantially eliminated. In order that the portion of the work piece supported on the anvil 5|] will not be distorted, the top surface of the release lever 34 when in its upper position is inclined in the same plane as the adjacent surface of the anvil and the lower surface of the creaser foot 20 is similarly inclined.

It will, accordingly, be seen that by a slight change in the shape of the work table [2 and in the anvil 50, narrow strips of flexible work pieces may be folded without objectionable curling thereof taking place after being folded as often happens in present day folding machines of the intermittent feed type.

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

1. That improvement in the method of folding thin flexible work pieces by progressively bendingportions of the margin of a work piece partially back toward the body thereof and progressively pressing the partially formed fold, which comprises bending, during the pressing of the fold, said work piece from a substantially flat condition to a condition in which a portion of the body of the work piece which is to lie under posite to that in which the margin is bent.

2. That improvement in the method of folding thin flexible work pieces by progressively bending portions of the margin of a work piece partially back toward the body thereof and progressively pressing the partially formed fold, which comprises bending, during said bending and pressing operations, said work piece from a substantially fiat condition to a condition in which a portion of the body of the work piece which is to lie under the portion being folded is inclined in-a direction opposite to that in which the margin is bent.

3. That improvement in the method of folding thin flexible work pieces by progressively bending portions of the margin of a work piece partially back toward the body thereof and progressively pressing the partially formed fold, which comprises bending said work piece from a substantially 'flat condition to a condition in which a portion of the body of the work piece adjacent to the portion being folded is inclined in the opposite direction sufficiently substantially toequalize the resistance of the margin of the workpiece to' the pressing operationso as substantially to eliminate any tendency for the material to curl or twist after the completion of the folding thereof.

4. A folding machine comprising a. work table, means for progressively bending portions of the margin of a work piece partially backtoward the body thereof, and a cooperating hammer and anvil arranged to press the folded portion of the work piece and to feed progressively the work piece over the work table, said anvil having a surface inclined downwardly relative to the adjacent surface of the work support to cause the portion of the work piece underlying the folded margin to be bent in a direction opposite to that in which the margin is folded.

5. A folding machine comprising a work table, a folding finger reciprocable across the path of movement of a Work piece thereover to progressively fold portions of the margin thereof, a creaser foot cooperating therewith against which the margin of the work piece is folded, a cooperating-hammer and anvil arranged to press the folded portion of the work piece and to progressively feed the work piece over the work table, said work table and anvil being shaped to cause the portion of the work piece underlying the folded margin to be bent in a direction opposite to that in which the margin is folded.

6. A folding machine comprising a work table over which a work piece the margin of which is to be folded is fed, a folding finger movable across the path of movement of the work piece to form a fold in the margin thereof, a creaser foot cooperating therewith against which the margin of the work piece is folded by the folding finger, a cooperating hammer and anvil arranged to press the fold formed by the folding finger and to feed intermittently the work piece over the work table, said work table having a raised portion adjacent to the anvil for deflecting the work upwardly, said anvil having a surface inclined downwardly from the raised portion of the work table for permitting the work to be deflected downwardly, and a release lever arranged adjacent to the anvil and cooperating with the creaser foot to hold the work on the Work table during the folding thereof by the folding finger, the upper surface of said release lever being substantially parallel with the adjacent surface of the anvil.

CARL A. NEWHALLi

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