US3550545A

US3550545A - Sewing machine cutter attachment

Info

Publication number: US3550545A
Application number: US784570A
Authority: US
Inventors: William C Cremer
Original assignee: WILLIAM C CREMER
Current assignee: WILLIAM C CREMER
Priority date: 1968-12-18
Filing date: 1968-12-18
Publication date: 1970-12-29
Anticipated expiration: 1987-12-29

Description

3,163.136 12/1964 Pickett United States Patent William C. Cremer 925 Weiser St., Reading, Pa. 19601 [21 Appl. No. 784,570

[22] Filed Dec. 18, 1968 [45] Patented Dec. 29, 1970 [72] Inventor 54] SEWING MACHINE CUTTER ATTACHMENT 1 Claim, 4 Drawing Figs.

[52] 1.1.8.0 112/130 [51] Int. Cl D05b 37/04 [50] Field of Search 1 12/129, 130, 122, 252; 83/(1nquired) [56] References Cited UNITED STATES PATENTS 3,170.349 2/1965 Weinkle l 12/130X FOREIGN PATENTS 6.405.787 1965 Netherlands 1 12/129 Primary Examiner-H. Hampton Hunter Attorney-William J. Ruano ABSTRACT: Sewing machine cutter attachment for cutting cloth and comprising a pair of scissors movable vertically, downwardly onto the bed as the result of actuation of an electrical relay and thereafter operated when in the downward position for effectively cutting the cloth after completion of a sewing operation. Normally the scissors are held in an upward position well above the cloth.

INVENTOR. WILLIAM C. CREMER his ATTORNEY PATENTEU 050291970 3550, 545

SHE? 2 [1F 3 INVENTOR. WILLIAM C. CREMER his ATTOR NEY PATENTED B5229 mm SHEET 3 0F 3 INVENTOR. WILLIAM C. CREMER SEWING MACHINE CUTTER ATTACHMENT This invention relates generally to a sewing machine attachment and, more particularly, a cloth-cutting attachment operated by an electric relay.

An outstanding disadvantage of cutters for sewing machines, of known construction, is that they are not fully automatic in operation and gene rally include a guillotine type of cutter, which type requires a high degree of accuracy of the relatively movable shear blades, therefore, faulty operation often results since such accuracy is difficult to maintain as the result of vibration and other factors. Furthermore such cutters are dangerous to the sewing machine operators.

An object of the present invention is to provide a novel automatic, power actuated cutter attachment which is devoid of the above-named disadvantages and which is relatively safe in operation.

A more specific advantage of the invention is to provide a cutter attachment wherein scissorlike cutters are normally held at a high position in the machine above the cloth being sewn and upon completion of the sewing operation the cutter is automatically and quickly driven down into the bed wherein scissorlike cutters will cut the cloth with high efficiency and maximum safety.

Other objects and advantages will become more apparent from a study of the following description, taken with the accompanying drawings wherein:

FIG. 1 is a front, perspective view of a sewing machine equipped with an automatic cutter attachment embodying the principles of the present invention;

FIG. 2 is a front view of the cutter attachment and electrical operating means for operating the scissorlike cutter blades which are shown in the elevated, nonoperable position;

FIG. 3 is a side view of the attachment and operating means shown in FIGS. 1 and 2; and

FIG. 4 is a front view of the relay-actuated cutter shown in the operated position while on the bed of the sewing machine.

Referring more particularly to FIG. 1 of the drawing, numeral 2 denotes a sewing machine base or sideplate on which is mounted a cloth-cutting, power-actuated assembly generally denoted by numeral 4 and comprising a shaft 34 vertically movable by an activating block 32 slidably mounted on shaft 34. A shaft steadying block 40 surrounds and is rigidly connected to the lower portion of shaft 34 which is surrounded by a shaft steady block slide 44. A shear stop 38 is attached to block slide 44. Pressure block 46 supports a blade pressure spring 48.

The cutter attachment is scissorslike and comprises a fixed blade holder 14 and a swingable or pivotal blade holder 16. Fixed blade holder 14 supports stationary blade 8 while the swing blade holder supports the pivotal or swing blade 10.

A blade holder block 50 supports the blade pressure block 46 for applying the pressure of spring 48 to blade 10.

Poweroperating means includes a solenoid contained within cover 26 and comprising a solenoid core having mounted thereon a solenoid bracket 28 (see FIG. 4) connected to the solenoid connecting link 24 which is pivotally connected at 22 so that the knife moving arm will vertically move connecting link 18 which is pivotally connected to the swing knife blade holder 16 to effect a scissorlike cut of blade 10 relative to stationary blade holder 14 and stationary knife The operation of the fixed blade holder 14 and the swing blade holder 16 is substantially as follows:

Solenoid 26 activates the solenoid connecting link 24, pivotally moving the end 30 of arm 20 downwardly against block 32 which puts pressure on shaft 34 through the spring 36 on block 40 which is rigidly secured to shaft 34.

When shaft 34 moves down into cutting position and stops by engaging stop block 42, the knife moving arm 20 continues to move down through connection 18 which moves the swing blade holder 16 and blade 10. This blade 10 crosses the blade 8 as in a pair of scissors to effect the cutting action of the cloth.

Upon completion of the cutting action of the cloth the solenoid is deenergized thereby enabling the return spring 52 (see FIG. 2) to retract bracket 28 and the solenoid core thus effecting a pivotal lifting movement of arm 20 to reduce the compression of spring 36. Shaft 34 will then be lifted until it is limited from further movement by engaging stop 38.

A suitable limit switch is provided so that upon completion of the cutting operation, the solenoid will become deenergized and allow the return spring 52 to restore the various parts to their initial position as shown in FIG. 2. Then when another piece of cloth is to be cut, a switch will be closed to complete the solenoid-energizing circuit so as to repeat the cutting operation.

The solenoid switch is contained in an enclosure 27 and is operated by a switch operating arm 29 so that when the operator desires to cut the cloth, he will push against arm 29 in the left direction, as viewed in FIG. 1, to complete the solenoid circuit and effect cutting operation.

Thus it will be seen that I have provided an efficient, auto matically operable cutting attachment for a sewing machine, which attachment includes a scissorlike cutter which is vertically movable so that the entire scissorlike construction is moved into the bed before scissor cutting is effected, thus providing not only a high efficient scissors cutting action, but affording a maximum degree of safety for the operator.

While I; have illustrated and described a single specific embodiment of my invention, it will be understood that this is by way of illustration only and that various changes and modifications may be made within the contemplation of my invention and within the scope of the following claims.

I claim:

1. A cutter attachment for a sewing machine having a bed along which sewn cloth is fed in readiness for cutting. a vertically movable cutter in the form of a pair of scissors which is movable downwardly adjacent the upper surface of the bed prior to operation thereof, and electrical operating means comprising a solenoid and linkage means operated by said solenoid for vertically moving said cutter and effecting said scissorlike movement when adjacent said bed, and return spring-operated means for returning the scissors to an open position above said bed, said electrical operating means also including vertical shaft having a stop element thereon on which is seated the lower end of a spring which surrounds said shaft, a slidable element surrounding said shaft and resting on top of the other end of said spring, said linkage means operating to depress said spring together with said stop element to move said shaft downwardly upon energization of said solenoid.