US2752202A - Buff-making machines - Google Patents

Description

June 26, 1956 M. SCHLOSS 2,752,202

BUFF-MAKING MACHINES Filed 00x. 16, 1952 5 Sheets-Sheet 2 INVENTOR. Maze/s SCI-IL ass ATTORNEYS June 26, 1956 M. SCHLOSS 2,752,202

BUFF-MAKING MACHINES Filed Got. 16, 1952 5 Sheets-Sheet 3 2/ INVENTOR.

v Moan/s SCHLOSS ATTORNEYS June 26, 1956 M. SCHLOSS 2,752,202

BUFF-MAKING MACHINES Filed Oct. 16, 1952 5 Sheets-Sheet 4 IN V EN TOR. MORE/S Scuzoss ATTORNEYS 5 Sheets-Sheet 5 Filed Oct. 16, 1952 INVENTOR. Mame/s 50 /1085 ATTORNEYS BUFF-MAKIN G MACHINES Morris Schloss, New York, N. Y.

Application October 16, 1952, Serial No. 314,977

18 Claims. (Ci. 300- 1) The present invention pertains to improvements in bulf-making machines.

An object of the invention is to provide an improved machine for forming fabric bufiing sections and the like.

A further object is to provide a machine for forming a buifing section from a cylinder of buffing material by applying exterior pressures in circumferentially spaced longitudinal zones to collapse the cylinder conically inward, whereby the cylinder is converted to an annulus.

A further object of the invention is to provide a machine for forming multi-ply annular butting sections from strip fabric by the above method.

A particular object is to provide a machine of the above nature adapted to the manufacture of bufiing sections of the general type disclosed and claimed in my co-pending application, Serial Number 237,750, filed July 20, 1951, now Patent No. 2,637,149, May 5, 1953, but it will become obvious that the machine is not limited thereto.

A further object is to provide a device of the above type including a plurality of circumferentially spaced fingers adapted to engage the fabric cylinder from without and to swing radially inward to collapse the cylinder as noted, together with means to resist the collapsing motion from within the cylinder between the planes of swing of the outer fingers, by which means the annulus is formed with evenly spaced inner convolutions each including all plies of the fabric.

A further object is to provide a device of the type described including an outer set of fingers as noted, an inner set of fingers circumferentially spaced between the planes of swing of the outer fingers, pressure means to urge the inner fingers outward, and means to move the outer fingers inward with an effective force greater than that of the pressure means of the inner fingers, whereby the fabric is maintained under tension during collapse, so as to ensure uniformity of the evenly spaced convolutions of the annulus and close mutual conformation of adjacent plies of fabric throughout the assembly.

Other objects and advantages of the invention will become evident during the course of the following description in connection with the accompanying drawings, in which Fig. l is a vertical part-sectional view of the machine in initial or loading position;

Fig. 2 is a schematic diagram of the electrical control system;

Fig. 3 illustrates a spirally wound cylinder of fabric suitable for conversion to the annular bufling section;

Fig. 4 is a plan view of the forming fingers and their supports, the fingers being shown in final position, but without the butt thereon, in order to clarify the interrelationship of the two sets of fingers;

Fig. 5 illustrates the outward tautening of the fabric cylinder by the inner fingers;

Fig. 6 shows the cooperation of the inner and outer finger groups in collapsing the fabric cylinder;

2,752,202 Patented June 26, 1956 Fig. 7 shows the final collapsed position, the bufiing section being ready to receive its hub plate;

Fig. 8 is a vertical part-sectional view similar to Fig. 3 but with the annulus completed and the hub plate clamped; I

Fig. 9 shows the bufing section clamped on its mandrel, ready for stapling;

Fig. 10 is a cross-sectional view of the completed bulf= ing section; V

Fig. 11 is an exterior peripheral view of the same; and

Fig. 12 is a side view of the same.

Referring to Fig. 1, the numeral designates a base plate upon which is secured a vertical cylindrical column 21. An annular flange plate 22, secured to the top of the column 21, has pivotally bracketed to the dream ference thereof a circular row of outer and inner finger plates 23 and 24 respectively, these finger plates hereinafter being referred to simply as the outer and inner fingers for purposes of simplicity in subsequent description. The pivots 25 of all the fingers are disposed in the same circumferential line, with outer and inner fingers disposed alternately as illustrated in Fig. 4, so that the outer and inner sets of fingers are adapted to swing in circumferentially spaced radial planes with the planes of the inner fingers 24 between those of the outer fingers 23.

Each inner finger 24 is articulated to a downwardly extending rod 26 at a point 27 spaced radially outward from its fulcrum pivot 25. It will be understood, as noted, that all the inner fingers 24 are equipped with rods 26 as described, but to avoid a confusing multiplicity of lines in the drawings the greater portion of the rods have been cut away, those shown being understood as typical of all the others. The same method of showing is followed with regard to the outer fingers and related parts in certain of the drawings, in the interest of clarity while following the description.

The rods 26 are pivotally connected at their lower ends 28 to a flanged sleeve 29 vertically slidable on the column 21. Similarly, the outer fingers 23 are articulated at points 30 to rods 31 pivotally attached at -32 to a second flanged sleeve 33. The sleeve 33 is slidably guided at the top on the sleeve 29 and at the bottom on the column 21. A slotted lever yoke 34, having a fulcrum 35 supported in a frame 36 secured to the base 20, spans the outer sleeve 33 in engagement with lateral pins 37 secured therein, so that upward or downward movement of the yoke 34 moves the sleeve 33 upward or downward along the column 21. A second or upper lever yoke 38, also mounted on a fulcrum 39 in the frame 36, similarly engages lateral pins 40 secured in the inner sleeve 29 and projecting outward through vertical slots 41 in the outer sleeve 33, as shown through the broken-away zone of the column 21, Fig. 1. By the provision of the clearance slots 41 it will be seen that sleeve 29 or 33 may be moved up and down by their respective yokes without interfering with each other.

From the illustrated relationship of the main pivots 25 and shackle pivots 30 of the outer fingers 23, it will be evident that upward movement of the outer sleeve 33 from the position shown in Fig. l swings the outer fingers radially inward respecting the axis of the column 21, into the final position shown in Figs. 4 and 8, wherein the inner faces of these fingers lie substantially in an annular plane perpendicular to the said axis. Similarly, upward movement of the inner sleeve 29' swings the inner fingers 24 radially inward, or conversely, inward motion of the inner fingers 24 forces the sleeve 29 upward.

The numeral 42 generally designates a motor-driven hydraulic pump of well-known type, having an adjustable by-pass or pressure-regulating valve 43 connected in the usual manner from the discharge or pressure end 44 to the suction end 45 thereof, the suction end also being connected to a suitable fluid reservoir 46.

A single-acting hydraulic cylinder and piston combination 47, hereinafter referred to collectively as a hydraulic cylinder in accordance with common hydraulic parlance, is so Connected to the yoke 38 so as to exert its pressure downward thereon. Fluid pressure to the cylinder 47 is derived from the pressure end 44 of the pump 42 via a solenoid valve 48 and a flexible tube 49, the solenoid valve being of the normally closed type. A doubleacting hydraulic cylinder 50, preferably of greater effective diameter than the cylinder 47, is pivotally mounted on the base 20, and is operatively attached to the lower yoke 34 so as to be adapted to exert its principal or outward pressure on the yoke in the upward direction. The upper and lower ends of the cylinder 50 are connected respectively, through flexible tubes 51 and 52, with an electrically operated four-way or reversing valve 53, the latter in turn being connected through tubes 54 and 55 with the reservoir 46 and the pressure side 44 of the pump 42. In its normal or electrically de-energized position, the valve 53 holds the upper end of the cylinder 50 connected to the high pressure, so that the yoke 34 is held in downward position as shown in Fig. l.

A third hydraulic cylinder 56, of the long-stroke double-acting type, is mounted on an upper frame bridge 57 above and in axial alignment with the column 21 and the described finger assemblies. The downwardly directed piston rod 58 of the cylinder 56 has secured thereon an inverted cup 59 having a rear aperture 60 and a front slotted or cut-away portion 61. The cylinder 56 is equipped with a manually operable fourway or reversing valve 62 connected via tubes 63 and 64 respectively with the pressure and suction sides 44 and 45 of the pump 42. In normal position as shown in Fig. l, the valve 62 maintains the high hydraulic pressure in the lower end of the cylinder 56, so that the cup 59 is supported in upper position a substantial distance above the assemblies of fingers 23 and 24.

The numeral 65 designates a stepped annular plate, removably socketed in a shallow cup 66 secured concentrically in the top of the main supporting plate 22. The plate 65 has an upwardly extending central mandrel portion 67 which is forked to receive a flat latch 68, the latter retained by a pin 69 extending through an inclined Wedging slot 70 in the latch as shown in Fig. 7. In normal position the latch 68 is disposed vertically so as to fall within the circumference of the mandrel 67 as shown in Figs. l, 4, 5, 6 and 7. The plate 65 has an outer rim 71 adapted to support a sheet metal binder ring 72, as hereinafter set forth.

Fig. 2 illustrates diagrammatically the electrical connections and switching devices by which the operating cycle of the machine is controlled, these devices being shown in normal position corresponding to that of the machine in Fig. 1. In Fig. 2 the numeral 73 designates one of a pair of current supply conductors, the second being conventionally represented throughout by the ground indication 74.

A relay 75 has three normally open contacts 76, 77 and 78, all connected on one side to the supply conductor 73. The contact 76 when closed is adapted to complete a current connection from conductor 73 via a conductor 79 and one normally closed contact 86:: of a two-pole momentary action push-button switch 86 to the solenoid valve 48. A normally open push-button switch 80, of the momentary contact type, is also adapted to connect the supply line 73 to the solenoid valve 48 via the switch contact 86a as noted. A limit switch 81 of the self-closing type, also arranged to complete the above-noted circuit to the solenoid valve 48, is so located as to be held open by an adjustable actuator screw 82 on the upper yoke 38 when the latter is in the position shown in Fig. l. A second limit switch 83, of the normally open type, is similarly arranged to be thrown by a second actuating screw 84 on the yoke 38 by travei of the yoke a short distance downward beyond the position shown in Fig. 1, the first limit switch 81 being of the well-known construction having ample over-run movement, to prevent injury by the additional depression.

The second limit switch 83, as shown in Fig. 2, is adapted upon closure to complete an actuating circuit from the supply line 73 via a lead 85 to the relay 75. Similarly, the contact 78 of the relay 75 is also adapted when closed to complete a second or holding circuit from the line 73 via the second normally closed contact 86b of the switch 86 to the relay. The third contact. 77 of the relay 75 is adapted when closed to complete a circuit from the line conductor 73 via a lead 87 to the electrically operated four-way valve 53.

The relay 75 and the push-button switches and 86 are provided with a housing 88, Figs. 1 and 8, this housing being located on the upper bridge frame 57 to provide easy access to the push-button from the front of the machine.

Figure 3 illustrates a multi-layer fabric cylinder or blank 89 suitable for conversion to a bufling section by the machine, such a cylinder being preferably wound spirally from a continuous strip of bias-cut fabric with the outer and inner layers longitudinally sewed, as fully shown and described in my previously mentioned co-pending application Serial No. 237,750.

In the loading position shown in Fig. 1, it will be noted that the outer fingers 23 are inclined outwardly beyond their vertical position, while the inner fingers 24 are tilted slightly inward from the vertical. This provides a V-shaped annular space between the rows of fingers into which the fabric cylinder may readily be loaded.

In practice, the operator first turns on current to the electrical system by any suitable type of main switch 90, Fig. 2. The motor 42a of the hydraulic pump 42 is thereby started, placing the discharge side of the hydraulic system under pressure while circulating the fluid through the by-pass valve 43. The operator places a binder ring 72 on the mandrel plate 65, then places the fabric cylinder 89 in position between the rows of fingers, the inner fingers 24 guiding the cylinder loosely into place as shown in Fig. l. The operator next pushes and holds the button-switch 80 closed.

Closure of the switch 80 energizes the solenoid valve 48, which opens to admit high pressure fluid to the hydraulic cylinder 47. The latter thrusts the yoke 38 downward, thereby also moving the sleeve 29 downward. By this motion the inner fingers 24 are swung outward against the fabric cylinder 89, drawing the latter taut as shown in Fig. 5. At the same time the actuating screw 84 on the yoke 38 encounters and closes the second limit switch 83. which in turn closes the relay 75.

Closure of the relay completes its own holding circuit through the contact 78, and closes a holding circuit for the solenoid valve 48, via the contact 76, allowing the operator to release the push-button switch 80. At the same time the contact 77 completes a circuit to the reversing valve 53. Operation of the valve 53 reverses the hydraulic connections of the cylinder 50, admitting high pressure fluid to the lower end of the cylinder and opening the upper end to the low pressure reservoir 46. The yoke 34 is thereby forced upward, raising the sleeve 33 and, through the medium of the rods 31, swinging the fingers 23 inward.

As the fingers 23 swing through their vertical position, they embrace the cylinder 89 and press it inward against the resisting pressure of the inner fingers 24. It will be noted that the radial distances from the shackle joints 30 of the outer fingers 23 to their fulcrum pins 25 are substantially greater than the corresponding distances on the inner fingers 24, giving the outer fingers greater operating leverage. This fact, together with the previously mentioned greater eifective diameter of the hydraulic cylinder than that of the cylinder 47, causes the inward forces of the fingers 23 to be much greater than the resisting outward forces of the fingers 24. Consequently, the outer fingers collapse the cylinder conically inward against the resistance of the inner fingers, as shown in Fig. 6, the collapsing forces being transmitted through tension of the fabric wall to the inner fingers. As the inner fingers 24 are evenly spaced to engage the fabric cylinder between the radial planes of motion of the outer fingers, and as the inner fingers maintain their resisting pressures as they are forced inward, the fabric wall is formed in a series of regularly spaced tapering convolutions 91. Thus the two finger groups, cooperatively grasping the fabric blank and maintaining it under tension, continue to collapse the blank until it is forced into the form of a corrugated annulus 89a as shown in Fig. 7, the inner circumference of the annulus embracing the periphery of the mandrel plate 65. At this point the hydraulic cylinder 50 completes its stroke and stops under pressure, so that the annulus 89a remains clamped in proper shape and position between the forming fingers.

The annulus 89a thus having been formed, a sheet metal hub plate 92, Fig. 7, is first pushed down the guiding mandrel 68 into overlapping contact with the inner zone 94 of the fabric annulus, and a pressure plate 93, of smaller diameter than the hub plate 92, is placed on the top of the latter. The valve 62 is then thrown to the operating position shown in Fig. 8, causing the hydraulic cylinder to thrust the cap 59 downward against the pressure plate 93, clamping the inner zone 94 of the annulus between the ring 72 and the hub plate 92. The operator topples the latch 68 forward until it lies flat on the pressure plate 93, then thrusts it rearwardly until the pin 69 is wedged against the inclined lower side of the slot 70, as shown in Fig. 8. He then throws the valve 62 back to normal position, whereupon the hydraulic cylinder 56 retracts the cup 59 upward, leaving the assembly of mandrel plate 65, binder ring 72, hub plate 92 and pressure plate 93 securely clamped together by the wedge latch 68.

To release the formed fabric annulus 89a from the forming fingers, the operator depresses the push-button switch 86, opening both its contacts 86a and 86b, Fig. 2. The opening of contact 86a de-energizes the solenoid valve 48, allowing the latter to close, thereby shutting off the first hydraulic cylinder 47 from the source of pressure fluid. At the same time, opening contact 86b breaks the holding circuit of the relay 75, allowing the latter to return to normal open-contact position. The opening of the relay contact 77 in turn de-energizes the reversing valve 53, alloWing the latter to switch the high pressure fluid supply back to the upper end of the hydraulic cylinder 5i) and releasing the pressure from the lower end thereof. As the result of the above-noted valve changes, the cylinder 56 forces the yoke 34 and sleeve 33 down ward, swinging the fingers 23 upward and outward to their normal position shown in Fig. 1, while the inner fingers 24 remain stationary under the annulus 89a until the operator releases the switch 86. When this switch is released, closure of the contact 86a again opens the solenoid valve 48, causing the cylinder 48 to swing the inner fingers 24 upward, freeing and elevating the annulus 89a together with its clamped assembly parts including the mandrel plate 65, as shown in Fig. 9.

The operator may stop the upward movement of the fingers 24 at any desired point by again pushing open the button-switch 86, or he may allow the fingers to continue their swing until they are stopped in normal loading position by opening of the limit switch 81, as previously explained in connection with Fig. 1. In either case the annulus 89a is freed and elevated to convenient unloading position.

The annular buffing section 89a, still clamped on its mandrel plate 65, is removed from the forming machine,

6 and the binder ring 72 and hub plate 92 are permanently secured tightly on the inner zone 94 of the annulus by through-stapling on a suitable stapling machine, which may be of any well-known type. Thereafter the wedging latch 68 is released, allowing the mandrel plate and pressure plate 93 to be removed from the completed bufiing section, these fixture parts then being replaced on the forming machine to receive another fabric annulus. In production it is the practice to provide two or more mandrel assemblies for each forming machine, in order that the latter may be kept continuously in operation while the previously formed bufiing sections are being stapled. While the hub plate 92 is illustrated as a plain type, the mandrel plate 65 may obviously be recessed to receive any desired form of plate, such as the louvred form shown in the previously mentioned co-pending application.

The operation of the forming machine as described, in addition to being rapid, uniform and easily attended, produces buifing sections having greatly improved structural features, as may be most readily ascertained in connection with Figs. 10, 11 and 12. By employing a blank 39 comprising a cylinder spirally wound from a continuous strip of fabric, the method of collapsing the cylinder conically produces an annulus of helically disposed plies without the necessity of any pre-rufiling or gathering of one edge of the fabric strip. Instead, the inner zone 94 is made up of a regular series of closely packed convolutions 95, Fig. 10, each convolution comprising all the layers of fabric in direct unwrinkled contact. This smooth and intimate contact between all adjacent layers of fabric continues outward as the convolutions 95 taper to the form of waves 96 at the periphery, as shown in Figs. 11 and 12. Thus the intimately associated fabric layers are mutually supporting throughout the structure, resulting in a buff of superior firmness, strength and inherent balance not attainable by prior methods of construction involving pre-gathering of the individual fabric layers, with consequent haphazard contact between adjacent layers and resultant flutfiness.

The above noted superior results achieved by the machine ef the present invention are particularly advantageous in forming buffing sections of the type described and claimed in my previously mentioned application, Serial No. 237,750, in which the fabric cylinder is wound from a strip of bias-cut fabric having relatively stiff warp or working threads and soft filler threads, the warp threads all being slanted across the strip in the same direction. Collapsing such a cylinder conically by the method herein set forth produces an annulus in which all the warp or working threads are inclined from the radial in the same rotary direction, resulting in a dual-purpose bufi ideally adapted to roughing when revolved in one direction and to polishing when revolved in the other direction, the above-noted inherent firmness and regularity of the structure permitting these operational advantages to be realized in maximum degree.

It will be evident that the machine is readily adapted to the forming of buffs of different desired thickness and/ or depth of peripheral waves 96, etc., by proper proportioning of the fabric cylinder 89. For example, a fabric cylinder of a comparatively large number of plies, fitted closely to the inner fingers 24 in the loading position, Fig. 1, will result in a thick bufling section with shallow peripheral waves, while a cylinder of fewer plies and greater initial diameter produces a thinner annulus with deeper peripheral waves. In forming any particular proportion of buff, the peripheral height of the mandrel plate 65 is normally made slightly less than the thickness of the inner fabric zone 94 as the latter is deposited on the mandrel by the forming fingers, as illustrated in Fig. 7. This arrangement causes the inner convolution zone 94 to be highly compressed by clamping action of the upper hydraulic cylinder 56, so that when stapled,

the clamped hub structure is of ample strength and firmness to prevent centrifugal loosening at the highest operational speeds. The staples 97 are preferably applied in inclined overlapping relation, as shown, in Fig. 12 and as set forth at greater length in the previously mentioned co-pending application.

As has been previously pointed out, a prime factor in producing the complete uniformity and compactness of the fabric convolutions is the controlled maintenance of the fabric wall under tension throughout the collapsing operation. It is evident that the amount of this tension, due to the resistance of the inner fingers 24, is a function of the thrust of the hydraulic cylinder 47. Therefore, if it is desired to vary the tension for different types of fabric, different proportions or hardness of buff, etc, this may be done simply by adjusting the regulating bypass valve 43 to change the hydraulic pressure of the system. Such adjustment in no way alfects the action of the outer fingers 23, for as previously explained, their effective forces are always proportionally greater than the corresponding resisting forces of the inner fingers 24.

While the invention has been described in preferred form, it is not limited to the precise embodiment illustrated, as various changes and modifications may be made without departing from the scope of the appended claims. For example, While stepped abutments 24a on the fingers 24 are utilized to support the cylinder 89 initially in loading position, Fig. t, it is evident that if desired, stationary quadrants may be provided between the fingers to perform this function.

I claim:

1. In a device of the character described, in combination, a circular support, an inner plurality of circumferentially spaced fingers pivoted to said support to swing inward thereon in radial planes from positions substantially in a cylindrical surface parallel to the axis of said support to positions substantially in a common plane normal to said axis, an outer plurality of circumferentially spaced fingers pivoted to said support to swing inward thereon in radial planes intermediate said first mentioned radial planes from positions outwardly beyond said cylindrical surface to positions substantially in said common normal plane, and means to swing all said fingers from said outer positions simultaneously into said inner position.

2. A device as claimed in claim 1 wherein said inner plurality of fingers is adapted to engage the interior of a fabric cylinder placed thereon, including means to press said inner fingers outward against said interior of said fabric cylinder, and wherein said swinging means includes pressure means to urge said outer fingers against the outside of said fabric cylinder with an effective force greater than the resisting force of said pressing means of said inner fingers.

3. In a buff-forming machine, in combination, means to support a hollow cylinder of bufiing material, means exterior to said supporting means adapted to collapse the wall of said cylinder conically inward from one end thereof to convert the same to a single annulus having an interior periphery comprising one end edge of said cylinder, and interior resisting means to maintain said wall under tension throughout said collapse.

4. In a buff-forming machine, in combination, means to support a hollow cylinder of bufiing material, exterior means surrounding said supporting means and adapted to collapse the wall of said cylinder conically from one end thereof to convert the same to an annulus, one end of said cylinder becoming the interior surface of said annulus, conically yieldable interior resisting means to maintain said wall under tension throughout said collapse, and adjustable means to regulate the degree of said tension.

5. A device as claimed in claim 4 wherein said exterior collapsing means is adapted to engage said wall in a plurality of circumferentially spaced longitudinal zones, and

wherein said resisting means includes means engaging the interior of said wall in separate zones spaced intermediate said first named zones, whereby said annulus may be formed with circumferentially spaced radial corrugations.

6. A device as claimed in claim 4 wherein the longitudinal extent of said exterior collapsing means is less than the length of said cylinder whereby said annulus may be formed with a narrow interior circumferential zone extending radially inward beyond said collapsing means, and including means to clamp said annulus throughout said interior circumferential zone thereof.

7. A device as claimed in claim 4 wherein the longitudinal extent of said exterior collapsing means is less than the length of said cylinder whereby said annulus may be formed with a narrow interior circumferential zone extending radially inward beyond said collapsing means, including means to clamp said annulus throughout said interior circumferential zone thereof, and means to retract said exterior collapsing means from said clamped annulus.

8. In a device of the character described, in combination, means to support a pliable blank of cylindrical form, exterior means surrounding said supporting means and adapted to collapse said cylinder conically from one end thereof to convert the same to an annulus having its interior surface formed from one end of said cylindrical blank, and interior resisting means cooperative with said exterior collapsing means to maintain the wall of said blank under controlling stress throughout said collapse.

9. A device as claimed in claim 8 including fluid-pressure means connected to said resisting means and operable therethrough to produce said controlling stress, and adjusting means to vary said fluid pressure.

10. In a buff-forming machine, in combination, a support, a removable cylindrical mandrel plate centrally retained on said support, means on said support to hold a hollow fabric cylinder in concentric relation to said mandrel plate, said fabric cylinder being of substantially greater inner diameter than said mandrel plate, and means on said support to collapse said fabric cylinder conically from one end thereof to convert said cylinder to an annulus having its internal surface formed of one end of said cylinder and embracing the periphery of said mandrel plate.

11. A machine as claimed in claim 10 wherein said mandrel plate has a lower flange adapted to support a binder ring, said binder ring being engaged by one side of the inner zone of said annulus on said mandrel plate, means on said mandrel plate to guide a second circular binder member concentrically into engagement with the other side of said inner zone, means to compress said zone between said binder ring and said second binder member While said collapsing means remains in engagement with said annulus, and means to lock said binder ring, said compressed zone of said annulus and said second binder member to said mandrel plate.

12. A machine as claimed in claim 10 wherein said collapsing means includes a plurality of fingers on said support in concentric relation to said mandrel plate, said fingers being pivotally mounted on said support in such directions as to be rockable radially inward toward said mandrel plate.

13. In a buff-forming machine, in combination, a support, a removable mandrel plate centrally retained on said support, a circular row of fingers individually pivoted to said support with all their pivotal axes tangent to a common circle concentric with and of substantially greater diameter than said mandrel plate, said row comprising alternate fingers shaped respectively to engage the inner and outer surfaces of a fabric cylinder placed therebetween, and means to rock all said fingers cooperatively inward whereby said cylinder may be conically collapsed into an annulus with the inner surface thereof embracing the periphery of said mandrel plate.

- 14. A device as claimed in claim 13 including means to yieldingly force said inner fingers against the wall of said cylinder, and wherein rocking means comprises means to press said outer fingers inward against said Wall with an eifective force greater than said yielding force or" said inner fingers.

15. A device as claimed in claim 13 including means operable by a fluid pressure to force said inner fingers against the interior surface of said cylinder, and wherein said rocking means comprises means operable by said fluid pressure to press said outer fingers against the outer surface of said cylinder with an effective force greater than said force of said inner fingers.

16. A device as claimed in claim 13 including means operable by a fluid pressure to force said inner fingers against the interior surface of said cylinder, wherein said rocking means comprise means operable by said fluid pressure to press said outer fingers against the outer surface of said cylinder with an effective force proportionally greater than said force of said inner fingers, and including adjusting means to vary the magnitude of said fluid pressure.

17. A device as claimed in claim 13 including means to clamp said annulus to said mandrel plate.

18. In a device of the character described, in combination, a support, means on said support to position a hollow cylinder of bufiing material, means on said support to collapse said cylinder single-comically into an annulus, and means operable by fluid pressure to apply an interior resisting force to the wall of said cylinder during said collapse.

References Cited in the file of this patent UNITED STATES PATENTS 626,300 Rogers et al. June 6, 1899 1,166,639 Hill Jan. 4, 1916 1,296,409 Levett Mar. 4, 1919 2,291,524 Best July 28, 1942 2,559,385 Bahr July 3, 1951 2,650,861 MacFarland Sept. 1, 1953

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