US1290272A - Stripper-foot for cloth-cutting machines. - Google Patents

Description

H, MMWHN. SHHPPEH FGOT FUR LUTH CUTTING MACHINES?.

APPLICATION FILED FEB. 14. i917.

'Patented Jan. 7, 1919.

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HYMAN MAIMIN, or NRW YORK, N. fr., AssIeNoR rro r1. Marr/IIN oo., INC., .e

. oORroRA'rIoN or NRW YORK. i i

STRIPPEBi-FOOT FOB CLOTH-CUTTING MCHINES. p

nascere.

Speccation of Letters yatent.

`Patented Jan. '7, 1919.

` Application filed February 14:. 1917. Serial No. 148,538.

.To all whom t may concern:

lBe it known that I, HYMAN MAIMIN, a citizen of the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Stripper-Feet for Cloth-Cutting Machines; and lfdo hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.I

This invention relates to presser feet or strippers for cloth cutting machinesand has been particularly applied to that type of a machine in which there is employed a reciprocating knife having a vertical cutting edge. It is common in such machlnes'to form the presser foot with a convexunder surface which permits an easy entry of the cloth to be cut. The presser foot is extended rearwardly in a forked shape, and sometimes Vmade to extend completely to the rear of the knife standard. ln some instances the curvature of the foot is suchthat the point of maximum pressure is immediately beneath the shankof the presser foot and well forward of theknife.` In other instances, and more commonly, the curvature is such that the region of maximum pressure is along the sides of the knife or knife-standard, the flat under surfaces of the two prongs ofthe fork establishing extended stripping surfaces of substantially equal pressure throughout the region at both sides of the cutting edge and the region immediately 1n front thereof. It is common practice with such machines to encounter a checking of the forward movement ofthe machine, and often a swerving from the intended line ofcutting, as well as adelay inthe cutting operation, due to the puckering or bunching of the cloth under the stripper foot.

l have discovered that a remarkably effectivestripper foot, which eliminates all liftingand puckering of the cloth, may be `produced by so shaping the stripper foot that the stripping pressure is concentrated in two projecting `tongues or fingers lying `close to the line of` cut and a short distance `in front of thevertical cutting edge ofthe knife, The arrangement isparticularly effective ifthe projecting tongues or fingers fare produced by cutting away the stripper ffoot between its shankand` the forward edge of :the knife to Aforma `sight opening, the

rearward extremities of which constitute the progecting tongues or fingers. This arrangement, in combination witha proper shaping of the under surface ofthe stripper foot, not only adords a definite sight opening through which the line of cut may be observed, but also has the beneficial eifect `of relieving the pressure on the cloth at the region-"immediately ahead ofthe stripper tongues or fingers. The invention will be understood more clearly fromthe following description when taken in connection with the accompanying drawing` illustrating a preferred form ofthe invention. i

In thisdrawing, Figure 1 is a front elevation showing the base-plate, knife and standard of a cloth cutting machine, and showing such machine equippedwith a combined knife guard and stripperfoot structure of the flying wing type illustrated in my Patent No. 1,207,780 of December 12` i916; `Fig. 2 is a view in sideelevation looking to the left of Fig. l; Fig. 3 is a view similar to Fig. 2 but looking to .the right of Fig. 1, and showing a 'pile of cloth asact-ed on by the stripper foot; and Fig. t is a horizontal sectiontaken on line l-4l of Fig. 3, with the pile of cloth removed.

` rIhe cloth cutting machine here illustrated has a base-plate 5, a standard 6, a knife 7 and an adjustable block 8, all of standard construction. `'lhis block 8 'has pivotally mounted thereon a pair of intermeshing gears 9, `provided with offset arms to which are secured".guardfmembers 11, the guardmembers carrying at their lower ends a pair Aof complementary stripper-foot sections or wing-me1nbers l2 and 13, and the block 8 being'vertically adjustable on the standard 6 toarrange the stripper-foot structure at the properheight above the base-plate 5 to compress any desired pile of cloth, all as is well known. A compression spring 14 is anchored at its opposite ends to studs carried by the internoeshing` gears 9, thisfarrangement permitting` a single spring to yieldinglv `hold the complementary stripper foot WingmemberslZ and 13 in either of their ex- ,ftreme positions of adjustment, that is, this spring tends to hold the wing-members whether they are interengaged` to` embrace the knifefblade as illustrated, or whether they have been swept upward and away from the knife and holdl the wing `members at opposite sides of and above the knife to bend inV the fork.

facilitate sharpening as is shown in my patent referred to above.

In order that the stripper foot sections may be positively locked together when arranged to embrace the knife 7, complementary latch elements are carried by the wingmembers 12 and 13. As shown most clearly in Fig. 4L, wing-member 12 has a laterally offset extension 15 provided with a suitable latch recess which receives a keeper formed by the downturned endef a latch-lever 16 as shown. This lever is pivoted on the usual forward extension ofwing-member 13; this extensionbeing provided to serve as a guide for the operator so that he may easily follow the proposed line'of cut as marked on .the goods. A suitable spring 17 is associated withy the latch lever, and the laterally offset extension 15 of wing member 12 is slightly iampedjas indicated at 151 in Fig. l whereby as the guard members 11 are lowered to bring the wing- members 12 and 13 together the latch elements carried Vby said wing members are automatically snapped yinto locking engagement.

It/will be noted that when the stripper foot structure isY assembled to embraceV the knife, suchV structure forms a fork Within which is extended theknife 7 with the vertical cutting ledge thereof nearest to the In other words, there is provided a U-shaped structure which embraces the Vforward cutting edge and sides of the knife but which is not extended far enough in rear yof the vertical cutting edge ofthe knife to embrace the back portion of the knife' standard.

VThe knife-adjacent edgel of wing-member 13 isnotched as shown at 18 and the knife adjacent edge of the wing member 12 is notched at 20, these .notches together formingna sight opening in front of the knife edge. The portions of the two wing-membersahead of the sight opening serves, be-

cause of the convex shape of the under surface of the stripper foot, to gradually compress the layers of cloth between the presser foot and the baseplate. The portions of the stripper footin rear of the notches 18 and 20 constituting kthe sight opening are curved upwardly as shown to gradually release the lpressure on the cnt cloth. Closely adjacent to the line ofcut on opposite sides thereof, and ay short distance in front of the cutting edge of the knives, theY projections or fingers 19 and Y'21, which are formed by the termination of therespective notches 18 and 20, serve as strippingv points, comparable their effect to that which would be produced by the fingers of the operator placed at these points and firmly` pressed downwardly. It isV found that thebest eect is produced if these projections or fingers are staggered, so that one is slightly farther ahead of the knife edge than the other, although this arrangement is not essential. In the particular embodiment of the invention which l prefer, the projection 21 is spaced apj'u'oximately one-sixteenth of an inch ahead of the vertical cutting edge of the knife and the project-ion 19 is slightly ahead of the .proj eetion 21.

In order to concentrate the stripping` pressure at the region of these stripping projections or fingers, the convex under-surfaces of the wing members 12 and 13 are shaped to compress the pile of goods with maximum effect at a point 22, a certain distance ahead of the path of descent of the vertical cutting edge of the knife, as indicated at 23 in Fig. 3. The distance marks the degree of separation of the vertical cutting edge of the knife preferably from the corner 1S) in the direction of the proposed line of cut. Thus in Fig. 2, where the line V-V represents the line of descent of the vertical eutting edge of the knife and the line IfI-H is arranged at right angles to the line V-V and parallel to the top face of the baseplate 5 the line I-I-H contacts the convex undersurface of the stripper foot, at a point rFlocated said distance ahead of the vertical cutting edge of the knife; and it will be observed that either wing-member is shaped to compress the pile of goods with maximum effect at the point T but with less and less effect at points between said point T and the rear end of the wing-member.

I claim:

1. In a cloth cutting machine having a base plate which supports a knife and knife standard so that the base plate, may be passed under a pile of fabric to advance the standard through the pile while said pile is being cut, a stripper foot member having a curved lower surface provided with means for producing a maximum compression of the pile of fabric between said member' and the base plate at points on opposite sides of the line of cut and slightly ahead of the knife.

2. In a cloth cutting machine having a base plate which supports a knife and knife standard so that the base plate may be passed under a pile of fabric to advance the standard through the pile while said pile Y is being cut, a stripper foot member havin;`

with a sight opening lying in advance of the knife, and means for producing a maximum compression of the pile of fabric between said member and the base plate at points on opposite sides of the line of cut and between the knife and the sight opening.

4. In a cloth cutting machine having a knife and a knife-holding standard, a combined knife guard and stripper foot having a pair of separate guardmembers pivotally supported to swing away from the path of the knife in a plane substantially normal thereto, and two complementary stripper foot sections carried by the guard members, these complementary stripper foot sections when joined forming a U-shaped structure which is disposed to embrace the vertical cutting edge and sides of the knife to completely protect said cutting edge and to effectively hold down the cloth at points on opposite sides of the line of cut and slightly ahead of the vertical cutting edge of the knife.

5. In a cloth `cutting machine of the kind described, a stripper-foot consisting of two complementary sections shaped to form a fork within which the cuttingedge of the knife is extended so that during operation of the knife the stripper-foot overlies the uncut cloth ahead of the knife and holds the saine down at points on opposite sides of the line of cut, one of the sections being notched in its knife-adjacent edge to provide a cloth-compressing corner at a point closely adjacent to the line of out and slightly ahead of the vertical cutting edge of the knife.

(i. In a cloth cutting machine of the kind described, a stripper-foot consisting of two complementary sections shaped to form a fork within which the cutting edge of the knife is extended so that during operation of the knife the stripper-foot overlies the uncut cloth ahead of the knife and holds the same down at points on opposite sides of the line of cut, one of the sections being notched in its knife-adjacent edge to provide a cloth-compressing corner at a point closely adjacent to the line of cut and slightly ahead of the vertical cutting edge of the knife, and the other section being notched in its knife adjacent edge slightly ahead of the notch in the first section to form a second cloth-compressing corner at a point standard so that the base plate may be passed under a pile of fabric to advance the standard through the pile while said pile is being cut, a stripper foot member having a curved lower surface provided with means for producing a maximum compression of the pile of fabric between said member and the base plate at points on opposite sides of the line of cut and at different distances slightly ahead of the knife.

8. In a cloth-cutting machine having a base-plate which supports a knife and knifestandard so that the base-plate may be passed under a pile of fabric to advance the standard through the pile while such pile is being cut, a stripper foot formed and arranged to press down on and compress the pile between itself and the base-plate at points on opposite sides of and closely adjacent to the line of cut, each of said points being a short distance forward of the cutting edge of the knife, and one of said points being slightly ahead of the other.

9. In a cloth-cutting machine having a base-plate which supports a knife and knifestandard so that the base-plate may be passed under a pile of fabric to advance the standard through the pile while such pile is being cut, a stripper foot member formed and arranged -to press down on the pile to compress the pile between such member and the base-plate with maximum effect at points on opposite sides of the line of cut and slightly ahead of the knife, and a sight opening in the stripper foot member lying in advance of said points of maximum effect.

10. In a cloth-cutting machine having a base-plate which supports a knife and knifestandard so that the base-p1ate may be passed under a pile of fabric to advance the standard through the pile while such pile is being cut, a stripper foot member formed and arranged to press down on the pile to compress the pile between such 1nember and the base-plate, and having in its rearward portion a `fork to straddle the knife and standard, and being cut away to form a sight opening, the rearward extremities of which lie in the prongs of the fork to form projecting tongues or fingers lying close to the opposite sides of the line of out and slightly in front of the edge of the knife, the under surface of the presser foot being so shaped as to concentrate the stripping pressure at 'the region of the said projections or lingers.

In testimony whereof I affix my signature.

HYMAN MAIMIN.

Uopies of this patent may be obtained for ve cents each, byaddressing the Commissioner of Patents,

Washington, D. C.

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