US2748473A - Textile cutting apparatus - Google Patents

Description

June 5, 1956 T. T. CARAPUCCI 2,748,473

TEXTILE CUTTING APPARATUS Filed Sept. 23, 1955 United States Patent TEXTILE CUTTING APPARATUS Tracy T. Carapucci, Aldan, Pa.

Application September 23, 1955, Serial No. 536,094

Claims. (Cl. 3ll139) This invention relates to a power actuated cutting machine for textiles, having an upright, vertically reciprocating knife adapted to cut a plurality of layers of cloth in the manufacture of wearing apparel. More particularly, it relates to a cutting machine of the above type having a vertically movable self-sharpening mechanism provided thereon for maintaining the knife in properly sharpened condition, and has for an object to provide an improved guiding structure for the sharpening mechanism.

In cutting machines of the above type, the condition of the knife edge is very important for efliciency of operation as well as quality of production work produced. A keen, well-centered and perfectly true edge is highly desired to permit accurate cutting of the material.

In view of the above, it is a further object of the invention to provide a simple and inexpensive guiding structure for the sharpening mechanism of a cutting ma chine which structure may be applied to existing cutting machines in service as well as to new machines during manufacture.

A more specific object is to provide a guiding structure of the above type which may be applied to cutting machines in service by inexperienced personnel in a few minutes with ordinary tools.

Yet another object is to provide an arrangement permitting the machine operator to follow a chalk line more accurately without resorting to the dangerous practice of lifting the presser foot.

Briefly, the invention resides in providing guiding means on the bifurcated presser foot which cooperate with the standard so that the support rod for the presser foot is steadied and acts as an accurate guide for the sharpening mechanism. The elongated portions of the presser foot are further provided with flexible portions permitting the trailing portion of the foot to yield upwardly when the lay of cloth bunches, thereby permitting the presser foot to free itself of such bunching without lifting by the operator. Also, the open area disposed within the bight of the presser foot is elongated and given a V-shape to enable the operator to more accurately follow the chalked pattern lines.

The above and the objects are effected by the invention as will be apparent from the following description taken in connection with the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a perspective view of a cutting machine having the invention incorporated therein;

Fig. 2 is a view taken on line II--II of Fig. 1;

Fig. 3 is a view taken on line III-III of Fig. 1;

Fig. 4 is a fragmentary plan view showing a modified form of the improved presser foot; and

Fig. 5 is a fragmentary sectional view taken on line VV of Fig. 4.

Referring to the drawing in detail, especially Figs. 1 and 2, the invention is embodied in a typical cutting machine generally designated 10, having a base 12 adapted to rest upon and be moved about a table or other surface 2,748,473 Patented June 5, 1956 supporting the cloth or other material to be cut. A standard 13, rigidly attached to the base 12 and extending upwardly therefrom, has supported thereon a stationary housing 14 which encloses an electric motor at 15, con trolled by a switch 15a, for driving a vertically disposed knife 16. The knife 16 is reciprocated in a vertical groove 17, provided in the standard 13, by the motor through appropriate driving mechanism (not shown) to which the knife is secured at its upper end.

A bifurcated presser foot 18, made in accordance with the invention and subsequently to be described in detail, is attached to the lower end of a vertically adjustable rod 19 which extends through guides 19a and 19b provided, respectively, in the housing 14 and a movable carriage 20. As well understood in the art, the presser foot 18 is "ice adjustable to different elevations suited to difierent lays' of material to be cut.

The movable carriage 20 is generally V-shaped and is provided with a pair of diverging arms 21, 21 connected to a central portion 22. The carriage 20 carries suitable dual grinding mechanism 23, 23 for mechanically grinding both faces 16a of the knife 16 to a sharp edge at the win of the operator.

In the illustrated embodiment, for example, each grinding mechanism 23 comprises an endless band 24 of abrasive-coated material disposed below an associated carriage arm 21 and rotatably supported thereon by a pair of sheaves 25 and 26. The sheave 25 is connected to a vertical drive shaft 25a operatively connected to the motor 15 within the housing 14 in any desirable manner, by means not shown, and controlled by a lever 27.

The carriage 213 is slidably connected to the standard 13 by a spring-pressed guide member 28 slidably received in a V-shaped bracket 28a.

A pressure shoe 29, provided with a pressure pad 30 is pivotally supported in the carriage arm 21 at 21a behind each abrasive-coated band 24 in the region adjacent the face 16a of the knife 16 and biased against the band by a wire spring 31. Thus, the band is brought to bear against the face 16a of the knife.

The carriage 20 is driven in a vertical direction by a drive shaft 32 provided with double helical grooves. The drive shaft 32 is operatively connected to the motor 15 within the housing 14 in any desirable manner, by means not shown, and is also controlled by the lever 27.

As thus far described, the cutting machine is substantially conventional and operates in the following manner:

Assuming the motor 15 to be connected to a conventional electric power supply (not shown), the motor may be energized by movement of the switch 15a to the On position, whereupon the knife 16 is rapidly reciprocated and may be applied to the lay of cloth and the presser foot 13 adjusted to the height of the lay cloth, in a manner well understood in the art. As the cloth is cut, the knife edge formed by faces 16a eventually becomes dull and must be sharpened. To sharpen the knife, the lever 27 is depressed, whereupon the drive shaft 32 is rotated to actuate the carriage slowly downward for the length of the knife and then back to its extreme upper position. Concurrently therewith, the drive shafts 25a, 25a are rotated in unison, whereupon the abrasive-coated bands 24, 24 are moved past the faces 16a, 16a of the knife to restore the keen edge thereto.

Applicant has found that inherent play or looseness of the movable carriage 20 relative to the standard 13 deleteriously affects the sharpening operation, so that in repeated sharpening operations the straight cutting edge of the knife 16 is destroyed and becomes wavy in some instances or is ground away a greater amount at the bottom than at the top. In applicants prior patent application Serial No. 462,004, filed October 13, 1954 and assigned to Eastman Cutting Machine Company, there is 3 provided an arrangement for maintaining the movable carriage in true alignment with the standard 13 during the sharpening process. Although that arrangement is highly desirable and should give good trouble-free service, it is somewhat complex and expensive to apply to existing machines.

In accordance with the present invention, as best seen in Fig. 3, the presser foot 18 is provided with a leading portion 33 which is attached to the support rod in any desirablemanner and a pair of arms 34, 35 extending rearwardly therefrom. The arms 34, 35 extend past the knife 16 and are disposed on opposite sides of the standard 13. The standard 13 is of conventional cross-section and is provided with a trailing portion 13a of greater thickness than the leading portion 13b, thereby forming a pair of vertically extending shoulders 36, 37. The arms 34 and 35 are provided with a pair of opposed tabs 34:: and 35a, respectively, disposed in abutting engagement with shoulders 36 and 37.

At the juncture of the arms 34, 35 a substantially V- shaped notch 38 is provided having its apex 38a in axial alignment with the knife 16.

The abutment of the presser foot tabs 34a and 35a against the shoulders 36 and 37, respectively, serves to steady the rod 19 against bending and side play, so that as the carriage 20 moves thereupon during the sharpening process, the grinding mechanism is more accurately guided along the knife faces 16a.

If necessary, the arms 34, 35 of the presser foot may be adjusted by bending towards each other in the directions of the arrows X, Y to provide a smooth snug fit against the shoulders 36, 37. Such adjustment if required may also be effected to compensate for any wear incurred after prolonged use.

During a cutting operation, the V-shaped notch 38 serves as a guide, enabling the operator to accurately follow the chalk lines on the lay of cloth.

In Figs. 4 and there is shown a presser foot 118 illustrating a modified form of the invention. In this embodiment, the arms 134 and 135 are also provided with a pair of tabs 134a and 135a similar to the tabs of the first embodiment. However, trailing portions 134b and 1351) are flexibly attached to the arms 134 and 135, respectively, by fiat spring members 138 and 139.

With the above arrangement, during a cutting operation, the phenomenon known as bunching is substantially reduced, since any bunching creates an upward force that is effective to flex the trailing portions 134k and 135b upwardly. During such flexing, the presser foot rides over the bunched cloth, thereby avoiding jamming of the machine without the necessity of the heretofore practiced dangerous expedient of lifting the presser foot.

It will now be seen that the invention provides an extremely simple arrangement for guiding the carriage 20 which can be installed in the field by inexperienced help with simple tools.

It will also be seen that the invention provides an improved presser foot for a cutting machine which facilitates the cutting operation and permits more accurate cutting of the cloth patterns.

Although two embodiments of the invention have been illustrated and described, it is to be understood that the invention is not so limited and that various modifications may be made without departing from the scope of the invention.

What is claimed is:

1. In a cutting machine having a vertically disposed standard, a knife guided by said standard for vertical reciprocating movement, grinding means for sharpening said knife, a carriage for supporting said grinding means, and means including a vertical shaft for guiding said carriage in vertical direction during sharpening; a presser foot attached to the lower end of said shaft, said presser foot being bifurcated and having a pair of arms extending past said knife and disposed on opposite sides of said standard, said standard having a pair of oppositely disposed shoulders extending vertically, and said arms having a pair of tabs disposed in opposed relation to each other and in slidable abutment with said shoulders; whereby when said knife is sharpened, said presser foot serves to restrain said carriage against lateral movement.

2. The structure recited in claim 1 in which said presser foot has a substantially V-shaped notch at the juncture of said arms, said notch having its apex disposed in axial alignment with said knife.

3. The structure recited in claim 1 in which the end portions of said arms are flexible in vertical direction.

4. The structure recited in claim 3 in which said presser foot has a substantially V-shaped notch at the juncture of said arms, said notch having its apex disposed in axial alignment with said knife and acting as a cutting guide.

5. The structure recited in claim 1 in which each of said arms is provided with an end portion and a flexible leaf spring member interposed between said arm and said end portion, whereby said end portions are yieldable in vertical direction.

No references cited.

Images