US2049351A - Pinking device for sewing machines - Google Patents

Description

y Z3, J. BRUSSELL' 2,049,351

PINKING DEVICE FOR SEWING MACHINES Filed June 22, 1935 INVENTOR Jacob Brussell Patented July 28 1936 PATENT OFFICE PINKING DEVICE FOR SEWING MACHINES Jacob Brussell, New York, N. Y., assignor to Isadore Friedman, Roselle, N. J.

Application June 22, 1935, Serial No. 27,910

15 Claims. 01. 112-422) My invention relates to pinking devices for sewing machines, and in more detail, to improvements and changes in the pinking device which is the subject of my Letters Patent Number 2,010,216, granted August 6, 1935.

In the pinking devices now produced numer-r ous different spring means are used to forcea close contact between the knife blade and the shearing plate but these spring means often cause excessive wear of the knife blade and shearing plate; They do not prevent the knife blade from being held stuck against the shearing plate and do not aid in lifting the knife blade after the cutting action is finished anddo not give a desirable increasing pressure on the down stroke of the blade and a decreasing pressure on the up stroke. In addition, the present devices are not easily or finely adjustable. The construction of the knife blades and shearing plates is such that there is a tendency for the blade to dull quickly and for the blade to catch or be held in the shearing plate, the cloth wedging the two together.'

It is an object of my invention to produce a pinking device with a spring means which will force a close contact'between the, knife blade and the shearing plate in such a manner that there is a minimum of wear of the shearing plate and knife blade cutting edges, give a proper and a sufliciently directed force to prevent clogging of the moving parts, and produce a spring action which causes an increasing pres-.

sure of the knife blade against the shear plate on the downward stroke of the knife blade' and a decreasing pressure of the knife blade against the shear plate on the upward stroke of the knife blade and in addition, to provide an upward pressure on the knife element aiding its upward stroke.

Another object of my invention is to provide a simple strong pinking device in which the spring means is easily removed and finely adjustable.

A further object of my invention is to construct a pinking device in which there is a minimum of wear of the knife blade and shearing plate and in which the knife blade and shearing plate are so constructed that there will be no tendency for the cloth to become wedged between the knife blade and shearing plate and hold the two together.

I accomplish these objects by constructing a pinking device in which there is provided a coiled spring functioning against one arm of an angled pivoted bar, attaching to the knife of the pinker an extension provided witha roller co-acting with the other arm of the bar and by providing a concave face on the under surface of the knife and 'by constructing the side faces of the shearing plate past which the knife V passes with an angle of less than 90 degrees. 6

Further and more specific objects, features and advantages will more clearly appear from the detailed description given below taken in connection with the accompanying sheet of drawings which forms a part of this speciflcation.

Figure 1 of the drawing is a side view partly in section of my pinking device attached to a sewing machine, Fig. 2 is a plan view of my pinking device with the upper parts removed to show the base part and spring means more clearly, Fig. 3 is a vertical section through the center of the knife blade showing a detail and Fig. 4 is a detail showing the shear plate. In the drawing, l represents the base and 2 the head 0 with a needle attached of an ordinary sewing machine. The base I of the machine is cut away at 3 to provide room for parts of the pinker 4 which extend downward below the. base of the machine.

The pinker 4 is positioned on the base I of the sewing machine and is constructed with the base plate 5, bearing and shaft 6 and arm I in the manner described in my above mentioned patent application. means 8, pivot arm 9 and pin ID are also constructed as described in the above mentioned application so that the reciprocation of the driving means 8 causesthe arm 9 and pin III to reciprocate.

Attached to the pin I0 is the fork H which holds the knife element [2. This knife element, in general, is constructed similar to,the knife described in the previous application, but difiers in the respect that the under face l3 of the knife is concave shaped, undercut or scoop d out so that the angle between a side face I and the under face I3 is less than degrees and so forms a, sharp cutting edge. As in the previous In addition, the driving 30' material, and to prevent excess wear of the knife faces, the lower part of the side wall I6 of the shear plate I5 is cut away so that the angle between the face of the shear plate l5 and the side wall I6 is less than degrees.

By constructing the side wall of the shear plate in this way, only the upper edge of the wall touches the knife blade and so, little'wear is caused to the knife blade and as the lower part of the side wall of the shear plate slopes away from the knife blade, more room is provided so that waste material cut off can fall away and eliminate the possibility of clogging the knife against the shear plate.

In order to force a knife blade against the shearing plate, a spring means is provided which is constructed partly on the arm I, the base plate 5 and the knife fork H. V

The part of the spring means constructed on the arml extends through a hole H in the arm. A tube I8 is internally threaded at l9 on the outer end and externally threaded at 20 into' corresponding threads in the opening H. A rod 2| tipped at the lower end with the, shouldered contact head 22 rests in the tube I8, and the head 22 projects through the opening IT. The upper end of the rod 2| is provided with a sleeve 23 which is threadedinto the threaded part l9 of the tube. The outer end of this sleeve has an enlarged knurled head. A knurled threaded washer 23A is provided on the threaded part of the sleeve-so that it can be screwed close to the end of the tube. Extending around the rod 2| between the shouldered head 22 and the lower end of the sleeve 23 is a coiled spring 24 for providing the compression for the spring means.

Extending from the rear of the knife fork II is an arm, contact piece or link 25 which, after a bent part 26, terminates in a bearing 21 carrying a roller 28.

A bearing 29 is constructed on the base 5 and is provided with a pin or pivot 30 to carry the bent arm or lever 3|. The upper part of the arm 3| is bent slightly to form a suitable resting place against .which the head 22 can rest. The other part of the arm 3| is straight and forms a bearing for the roller 28.

The upper end of the spring 24 rests against the fixed sleeve part 23 while the lower end pushes the head 22 outwardbeyond the arm 1 and against the upper part of the arm 3|, thus forcing the lower part of the arm 3| forward against the roller 28. This causes the knife to be pushed forward against the shear plate and gives the necessary compression for cutting. The fact that the lower part of the arm 3| extends forward at its lower part causes an increased pressure of the knife blade against the shear plate as the knife and roller descend. Because of the forward direction of the lower part of the arm 3|, there is produced in addition to the necessary cutting compression and upward component which tends to aid the driving means in raising the knife. The compression of the system is regulated by turning the knurled sleeve which causes a corresponding change of pressure in the spring 241 and throughout the entire spring parts.

While I have described my improvements in great detail and with respect to a preferred form thereof, I do not desire to be limited to such details and forms since many changes and modifications may be made and the invention embodied in widely different forms without departing from the spirit and scope thereof in its broader aspects. Hence I desire to cover all and a bearing means on said extension to bear modifications, forms and embodiments coming within the language or scope of any one or more of the appended claims.

I claim:

1. A pinking device for a sewing machine hav- 5 ing a base plate, a bearing on said plate, an arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts. and a spring means comprising a hollow-tube extending from the arm, a rod in said tube extending through said tube and projecting beyond the arm, a spring in said tube about said rod and extending and providing spring action between the rod and tube, a bearing on said base plate, an angled bar pivoted in the bearing, an extension on said knife and a bearing means on said extension to bear against one part of the angled bar while the other part of the angled bar rests against the rod causing compression in the spring.

2. A pinking device for a sewing machine having a base plate, a bearing on said plate, an arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts, and the spring means comprising a hollow tube extending from the arm, a rod in said tube extending through said tube and projecting beyond the arm, a spring in said tube about said rod and extending and providing spring action between the rod and tube, a bearing on said base plate, 30 an angled bar pivoted in the bearing, the bar so angled that one part extends from the angle downward toward thebase plate and forward toward the knife, an extension on said knife against the downward forward part of the angled bar while the other part of the angled bar rests against the rod causing compression in the spring.

3. A pinking device for a sewing machine having a base plate, a bearing on said plate, an arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts, and a spring means comprising a hollow tube extending from the arm, a rod in said tube extending through said tube and projecting beyond the arm, a spring in said tube about said rod and extending and providing spring action between the rod and tube, a bearing on said base plate, an angle bar pivoted in the bearing, the bar so angled that, one part extends from the angle downward toward the base plate and forward toward the knife while the other part extends from the angle backwards toward the arm and curves downward near its end to form a bearing place against which the rod end rests, an angled extension on said knife and a roller means on said extension to bear against the downward forward extending part of the angled bar while the downward curving part of the bar through the rod compresses the spring.

4. A pinking device for a sewing machine having a base plate, a bearing on said plate, an arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts, and a spring means comprising a hollow tube 35 threaded at its outer end extending from the arm,

a rod in said tube extending through said tube and arm, a sheath about said rod having a head at its upper end and threaded at its lower end into the threaded end of the tube, a spring in 7 said tube about said rod and extending and providing spring action between the rod and sheath part threaded to the tube, said head part of the sheath being turned to vary the spring compression, a bearing on said base plate, an angled bar 75 pivoted in the bearing, an extension on said knife and a bearing means on said extension to bear against one part of the angled bar while the other part of the angled bar rests against the rod causing compression in the spring.

5. A pinking device for a sewing machine having a base plate, a bearing on said plate, an arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts; and a spring means comprising a spring, a carrier and holding means for the spring, and a functioning means through which the spring acts comprising a bearing on said base plate, an angled bar pivoted in the bearing, an extension on said knife and a bearing means on said extension to bear against one part of the angled bar while the other part of the angled bar rests against the spring holding means.

6. Apinking device for a sewing machine having a base plate, a bearing on said plate, an arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts, and a spring means comprising a hollow tube threaded at its outer end extending from the arm, a rod in said tube extending through said tube and arm, a sheath about said rod having a head at its upper end and threaded at its lower end into the threaded end of thetube, a spring in said tube about said rod and extending and providing spring action between the rod and sheath part threaded to the tube, said head part of the sheath being turned to vary the spring compression, a bearing on said base plate, an angled bar pivoted in'the bearing, the bar so angled that one part extends from the angle downward toward the base plate and'forward toward the knife while the other part extends from the angle backwards toward the arm and curves downward near its end to form a bearing place against which the rod end rests, an angled extension on said knife and a roller means on said extension to bear against the downward forward extending part of the angled bar while the downward curving part of thelbar through the rod compresses the spring.

'1. A pinkingdevice for a sewing machine having a base plate, a bearing on said plate, an arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts, and a spring means comprised of a spring attached to the arm, a bar, and a roller attached to the knife, the spring operating through the bar and roller to cause the knife to press against and cut in conjunction with the shear plate.

8. A pinking device for a sewing machine having a base plate, a bearing on said plate, and arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts, and a spring means comprised of a spring attached to said arm, a bearing on the base plate, an angled bar pivotally held in the bearing, and a roller attached to the knife, the spring operating against one part of the angled bar to cause the other part to press against the roller to cause the knife to contact with the shear plate. P 9. A .pinking device for a sewing machine having a base plate, a bearing on said plate, an arm pivotally held in the bearing, a knife held by the arm, a shear plate against which the knife cuts, and a spring means comprised of a spring attached to said arm, a bearing on the base plate, an angled bar pivotally held in the bearing, an arm attached to the knife and means on the arm, the spring operating against one part of the angled bar to cause the other part to press against the means on the arm of the knife to cause the knife to contact with the shear plate. 5

10. A trimming mechanism for sewing machines comprising a base, an arm pivoted on said base, means attached to said arm for reciprocating the same, a knife pivoted on the free end of said arm, a ledger blade cooperating with said 10 knife, a spring mounted on the rear of said arm, a pivoted lever between said spring and knife, said spring acting upon said lever, and a contact piece secured to said knife and operatively engaged with said lever.

11. A trimming mechanism for sewing machines comprising a base, an arm pivoted on said base, means attached to said arm for reciprocating the same, a knife pivoted on the free end of said arm, a ledger blade cooperating 20 with said knife, 9. spring mounted on the rear of said arm, a pivoted lever mounted on said base between said spring and knife, said spring acting upon said lever, and a contact piece secured to said knife and operatively engaged with said 25 lever.

12. A trimming mechanism for sewing machines comprising a base, an arm pivoted on said base, means attached to said arm for reciprocating the same, a knife pivoted on the free end of 30 said arm, aledger blade cooperating with said knife, a. coil spring mounted on the rear of said arm, a pivoted lever between said spring and knife, said spring acting upon said lever, and a contact piece secured to said knife and operatively engaged with said lever.

13. A trimming mechanism for sewing machines comprising a base, an arm pivoted on said base, means attached to said arm for reciprocating the same, a knife pivoted on the free end of said arm, a ledger blade cooperating with said knife, a. spring mounted on the rear of said arm,

a. screw threaded member contacting with the end of said spring and adapted to be manipulated to vary the tension of said spring, a pivoted lever between said spring and knife, said spring acting upon said lever, and a contact piece secured the tension thereof, a pivoted lever between said spring and knife, said spring acting upon said lever, and a contact piece secured to said knife and operatively engaged with said lever.

15. A trimming mechanism for sewing machines comprising a base, an arm pivoted on said base; means attached to said arm for reciproeating the'same, a knife pivoted on the-free end of said arm, a ledger blade cooperating with said knife, a spring mounted on the rear of said arm, a pivotedlever between said spring and knife, said spring acting upon said lever, and a contact piece secured to said knife andloosely engaged with said lever.

I JACOB BRUSSELL.

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