US2919468A - Machine for rolling plastic strips - Google Patents

Description

Jan. 5, 1960 l. SPINNER 2,919,468

' MACHINE FOR ROLLING PLASTIC STRIPS Filed March 6, 1956 2 Sheets-Sheet 1 w I? z '30 E {a 6 r I V 119 M {as 13 ml 115 I s -v 115 4L. 13

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' 2G2: [az'dare 5 inner Jan. 5, 1960 I. SPINNER 2,919,468

MACHINE FOR ROLLING PLASTIC STRIPS Filed March 6, 1956 2 Sheets-Sheet 2 1. 5251: 2E: v [51540]? jlznner shaped strips to form binders.

:wardlyit raises the detent.

United States Ihis'invention relates to a machine for rolling strips of thermoplastic or like material, particularly comb- A machine of the type gwith' which the present invention deals is described, for example, in the specification of British Patent No. 687,873..

f I'nIthemachine of the above-mentioned British patent, a magazine holds a stack of mandrel rods above a feeding table A mandrel pusher pushes the lowermost mandrel pasta spring-urged detent to a rolling station at the end of, the feeding table. As a mandrel approaches the rollingstation, a bight-forming roller is automatically raised under a shiftable, flexible band at the end of the feeding ,tableand forms a bight in the band extending part way around the mandrel. Flat plastic blanks or strips are automatically movedto the rolling station and, at the appropriate time, are automatically moved under and around themandrel to form plastic binder tubes.

With the machine just described, the shifting of the portion of theband forming the bight above the mandrel during the rolling operation exerts a force on the mandrel rod which urges it from the bight formed in the band. It is one of the objects of this invention to provide means ,which eliminates or substantially reduces this force.

It is another object of this invention to provide means for preventingasudden expulsion or ejection of a mandrel as itmoves from the magazine toward the rolling stavtion.v In accordan ce with the preferred aspect of the invention, a spring pressed braking detent is provided, the detent having a flat mandrel rod-engaging surface on the bottom thereof. The detent is preferably mount- ,ed for linear up and downmovement in an inclined direction. When the bottommost mandrel is pushed for- I v The fiat bottom edge of the detent is spring pressed with the mandrel rod to brake its motion. a

glnthe binder rolling operation, the overlapping portions'of the plastic tube are often fused or stuck to- :gether.'- It is another one of the objects of this invention to provide" means at the discharge station for facilitating quick and easy separation of the overlapped portions of the tube; In accordance with the preferred form of the invention, this-means includes a stripper plate which has a beveled. upper edge.

The Overlapping edge of the binder can be brought over theupper edge ofgthe aforementioned stripper plate which edge is used to loosen or separate the adhered overlapped portion of the binder.

, Qther objects, advantages and features of the inven- .-tion will be apparent upon making reference to the following specification, taken in conjunction with the drawingswherein:

j Fig-,1 is a fragmentary vertical section through a .portionof a strip rolling machine when it is in a position jin which a mandrel is about to be fed from the mandrel ,;;rnagazine to the rolling station;

atent 0 magazine 4 wh1ch compnses a pair of angle-shaped upthrough the machine of Fig. 1, taken along section line 2--2 in Fig. 1;

Fig. 3 is an enlarged elevational view of the mandrel magazine and the mandrel holding detent associated therewith;

Fig. 4 is an enlarged vertical sectional view through a portion of the machine of Fig. 1, when the machine is in its blank rolling position, with a bight formed in the shiftable band and a plastic blank in position to be Wrapped around the mandrel rod;

Fig. 5 is an enlarged vertical sectional view of the end of the ramp showing the mandrel with a plastic binder therearound in position for prying apart the overlapped portions of the binder; and

Fig. 6 is a perspective view showing the fingers being pried loose from the tube backbone.

The machineof Fig. 1 is essentially one such as is shown in British Patent No. 687,873 in which the present invention has been incorporated. For a more complete description of those parts of the machine necessary for its operation, but not illustrated here, reference is made to that British patent.

Reference should now be made to the drawings where like reference numerals indicate like elements throughout.

Referring more particularly to Figs. land 2, the overall organization of the portion of the machine shown in the drawings includes a feeding table 2 above which is supported a magazine 4 having a supply of mandrel rods 5, mandrel rod pushing apparatus 6 for pushing a mandrel through the discharge opening at the bottom of the magazine to a rolling station 7, strip pusher means 8 (Fig. 2) for pushing a plastic blank 9 under the magazine and to the 'rolling station, rolling instrumentalities 10 for wrapping a plastic blank around a mandrel at the rolling station, and motor driven operating mechanism 12 for operating the various instrumentalities of the machine in proper sequence. (With regard to Fig. 2, it should be understood that the plan view of the opposite longitudinal side of the machine not shown therein is substantially a mirror image of the parts there shown.)

Many portions of the machine to be described are shown and described more completely in British Patent No. 687,873.

The feeding table 2 which is carried upon laterally spaced angle bars 13 includes a main heated section 14 and a final heated section 16 spaced a small distance in front of the main section. v

The main table section 14 may be covered with a thin, scorch-proof linen to prevent sticking of the plastic blanks or strips 9. The final table section 16 is located slightly lower than the top of the main table section 14 for reasons to be explained hereinafter.

Supported above the feeding table is the mandrel right members 1818 each fixed or mounted to one of the angle bars 13 on opposite sides of the feeding table as in the British patent. Each upright lii'includes a longitudinally extending flange 19 (Fig. 2) which confines the ends of the mandrels 5, and a transversely extending flange 20 to confine the mandrels in the magazine against rearward movement. Associated with each angle shaped upright 18 is a vertically adjustable vertical plate 21 having a vertical rear edge in front of the flange 20 of theassociated upright 18, to confine the mandrels against forward movement in the magazine.

The bottom 29 (Fig. 3) of the flange is above the main feeding table section 14 a distance less than the diameter of the smallest mandrel to be used in the magazine. The bottom edge 21' of the adjustable plate 21is above the feeding table an amount slightly greater than the diameter of the mandrels used in the magazine, to permit free rolling of the mandrels toward the rolling station 7.

Supported on the inner face of each of the adjustable plates 21 is a mandrel retainer plate 22 having a vertical rear edge 24 and a horizontal bottom edge 26. The mandrel retainer 22 is mounted on the associated plate 21 and biased to one position by a helical spring 28. One end of the spring is anchored to the associated adjustable plate 21 by the head of a screw 30 threaded in the plate 21 and passing through a slot 31 in the retainer 22. The slot 31 is at an angle approximately 45 with respect to the horizontal. The other end of the spring is secured to the mandrel retainer 22 by a screw 32. The retainer 22 is guided for linear movement by the shank of the screw 30 and the shank of a headed screw 29 that passes through a slot 33 in the retainer 22 and threads into the plate 21, the shanks fitting in the respective elongated slots. The spring 28 urges the retainer 22 downwardly and rearwardly along a 45", angle line toward the discharge opening of the magazine located at the bottom of the magazine forming members 18 and 21.

When the rear edge 24 of the retainer 22 is opposite to and in alignment with the rear edge of the associated adjustable magazine plate 21, as seen in Fig. 3, the bottom edge 26 thereof is above the feeding table an amount less than the diameter of the mandrel rods being used. The bottom of the rear edge 24 thereby prevents the lowermost mandrel rod in the magazine from rolling out of the magazine onto the feeding table.

To adapt the magazine for different sized mandrels, the adjustable magazine plates 21 are each mounted for adjustable movement along a line extending 45 upwardly and forwardly away from the associated magazine upright member 18. In this way, the spacing of the rear and bottom edges of each of the adjustable plates 21, respectively, from the vertical flange 20 of the associated magazine upright member and from the feeding table are varied to the same degree. Thus, when the spacing between the rear edge of an adjustable plate 21 from the flange 20 of the associated upright magazine member is such as to accommodate a given sized mandrel, the spacing between the bottom edge of the adjustable plate 21 and the feeding table is automatically set to accommodate the same sized mandrel.

The plates 21-21 are vertically adjustable as shown in the aforementioned British patent. Sufiice it to say, associated with each adjustable plate 21 are a pair of vertically aligned, spaced gears 34-34 each carrying eccentric crank pins 36-36 which have slight radial freedom. Each pin passes through a 45 slot in the flange 19 of the associated upright member 18. These pins are each anchored at their ends to the associated plate 21. The gears 34 are operated by worm gears 38-38 which are secured to a common vertical shaft and are turned by a hand knob (not shown) at the upper end of such shaft. Turning of the gear members 34-34 moves the associated adjustable plate and the mandrel retainer member carried thereby generally upwardly and away or downwardly and toward the flange 20 of the associated upright magazine member 18.

In a manner to be explained, mandrels from the magazine are fed to the rolling station 7 over superimposed linen sheets or hands 40 and 41 extending over the final heated table section 16. The latter is set lower than the table section 14 by an amount approximately equal to the overall thickness of the sheets 40 and 41. At the rear of the final table section 16, thetwo bands extend around a transversely extending roller 42 mounted upon the angle frame members 13-13 of the machine. In the condition of the machine shown in Fig. 1, the uppermost band 41 passes above a movable, transversely extending bightforming roller 44 positioned ahead of the front end of the final table section 16, as in the British patent. The lower linen sheet 40 is below the roller 44. The bands 40 and 41 then pass down around a transversely extending roller 46 rotatably mounted between the angle members 13-13 of the machine. The roller 44 normally seats in recesses 47-47 formed in upstanding arms of the angle bars 13-13.

The forward ends of the bands 46) and 41 are connected together and to the same bar 48 that extends transversely of the machine. The opposite or rear ends of these bands are weighted by respective transverse bars 50 and 52, similar to the bar 48. The bars 48, 50 and 52 keep the bands taut.

The mandrel pusher means 6 are the same as in the British patent and include pushers 54-54 mounted for fore and aft movement on opposite sides of the feeding table. The means for periodically reciprocating the pushers are disclosed in said aforementioned British patent. As the forward ends of the pushers advance, they contact the rear of the lowermost mandrel in the magazine. As the pushers continue to move forward, they push the lowermost mandrel against the resiliently mounted mandrel retainer 2222 which are thereby moved upwardly and forwardly along 45 angle lines away from the mandrel discharge opening against the resiliency of springs 28-28. As the bottom edges 26-26 of the retainers rise above the lowermost mandrel, that mandrel is moved forwardly out of the magazine and beneath the retainers 22-22. The bottom edges 26-26 thereof then resiliently engage the top of the mandrel and act as brakes to prevent sudden expulsion of the mandrel from the magazine. The pusher members then push the mandrels past the front extremities of the retainer edges 26-26 to a pair of spring-loaded detents 55-55 having rearwardly facing inclined ramps and positioned on opposite sides of the table section 16. The detents 55-55 are extensions of a pair of plates 56-56 which are urged upwardly by helical springs 57-57. As the mandrel is pushed over the inclined rear ramp surface of the detents 55-55, the detents lower to let the rod pass. When the mandrel has been moved past the detents 5-5-55, the springs 57-57 bring the detents back to their raised positions to prevent return movement of the mandrel.

In a manner to be briefly explained herein, and as is more fully described in the aforesaid British patent, as a mandrel is fed to the rolling station, the aforementioned strip pusher means 8 pushes a warm, soft, plastic blank on the feeding table to the roller station. To provide clearance for passage of the strip pusher means over the feeding table to the rolling station, the lowermost mandrel must be raised above the feeding table. This is accomplished by ramps 58-58 carried by the mandrel rod pusher means 6 behind the pushers 54-54. As a mandrel is fed over the detents 55-55 to the rolling station 7, the ramps 58-58 engage the succeeding lowermost mandrel and raise the same the required distance.

As a mandrel is fed to the rolling station, automatically operated means move the bight-forming roller 44 upwardly and then rearwardly to bring the bight or fold in the uppermost band 41 part way around the latter mandrel at the rolling station, as shown in Fig. 4. This means includes arms 60-60 each extending through approximately 280 and mounted upon a transversely extending shaft 62. The ends of the shaft 62 carry sprocket wheels 63-63. The sprocket wheels are each engaged by a chain 64 which is adjustably connected at one end to an operating rod 66 loaded by a weight 68 and by a compression spring 70 abutting against a fixed rod guide 72. The other end of each chain is connected to an operating lever 74 which is moved up and down in proper timed sequence to the movement of other elements of the machine by mechanism, all as disclosed in said British patent. The loading of the former ends of the chains 64-64 serves to steady the movement imparted to the arms 60-60. As the lever 74 is moved downward, the sprocket wheels 63-63 are rotated in a direction to move the bight-forming roller 44 counter- I 80 rotatably mounted in fixed brackets 82-82 and are biased by a spring 84 acting on the shaft toward the position in which they enter notches 86-86 in the arms 60-60.-The latch levers 78-78 are moved toward their releasing or upward positions through an'operating rod 88 connected to the shaft 80 by linkage 89. The operating rod 88 is pulled down by a fork 90 straddling the rod 88 and carried by one of a pair of laterally spaced levers 91-91; The fork 90 engages a stop member 92 at the bottom of the rod 88. The latch members 78-78 are released in this manner following the completion of a rolling operation in the manner to be more fully explained hereinafter.

When the bight-forming roller 44 has been locked in position by the latch members 78-78 in the manner just discussed, the mandrel rod pusher means 6 is in the position shown in Fig. 4 with the ramps 58-58 thereof beneath the magazine to raise the lowermost rod above the feeding table as above explained. In a manner more fully described in the above patent, the strip feeding means 8, one of the elements of which includes an angle-shaped, horizontally extending arm 8' shown in Fig. 4, moves a comb-shaped plastic strip or blank, which has been softened by its movement over the main heated table section 14, onto the final heated table section 16 to the rolling station.

Means are provided for shifting both of the linen bands 40 (and with it the sheet 41) forwardly over the feeding table, as shown by the arrows in Fig. 4, to carry the plastic strip 9 beneath and upward around the mandrel rod at the rolling station to form a tubular binder element. This includes spaced bars 93-93 carried between the levers 91-91. As the levers 91-91 are moved downwardly from an upper position, the bars 93-93 engage the top of the rod 48 at the front ends of the linen bands to pull the same down and, in so doing, shift the band 40 to wrap the blank 9 around the mandrel rod 5. As the linen bands are thus shifted, the bightforming portion 105 of the upper band 41 above the mandrel rod 5 is shifted rearwardly and this but for the sheet 41 would tend to drag or force the mandrel to the left with a force determined by a number of factors, one of which is the resistance to movement of the portion of the band 40 that extends rearwardly of the mandrel, due to friction and weight of the parts being raised. This tendency is counteracted by the forward movement of the lowermost band 40 upon which the mandrel rod 5 also rests.

When the levers 91-91 reach a bottom position where the bands have been shifted to their limits, clamping means 94 are brought into operation to hold the bands in position while the levers 91-91 are raised. The clamping means 94 includes a clamping jaw 96 pivoted at 98 and controlled by a cam 100 which, at the appropriate time, pushes a spring-urged rod 102 secured to the clamping jaw 96 to the right as viewed in Fig. 1.

As the clamping means 94 is operated the latch levers 78-78 are tripped at the end of the rolling operation. Then, the lever 74 which operates the arms 60-60 moves upward to pivot the bight-forming roller 44 clockwise to unfold the loop in the uppermost band 41. The clamping jaw 96 is then released, and the bands 40 and 41 are then brought back to their initial positions as shown in Fig. l by the weights 50 and 52.

The mandrel 50 with the plastic blank or strip rolled around it then rolls freely down the ramp 106 having upstanding sides 108-108 and beneath guide plates 107-107 to a discharge station at the end of the ramp. An adjustable end plate 109 is located at the end of the ramp, and the front edges of the guide plates 107-107 terminate rearwardly of this plate a distance greater than the diameter of amandrel so that the latter may be raised upwardly out of the ramp.

The ramp 106 terminates in a depending flange to which is adjustably mounted the plate 109 by screws 113-413 passing through vertical slots 111-111 (Fig. 6) in the plate and threading into the depending flange 115. The front face 117 of the plate 109 is vertical, and a sharp edge 119 is formed along the top of the plate by a bevel 120. The-purpose of the edge 119 will be explained hereinafter.

In the rolling operation above described, the fingers 9' (see Fig. 6) of the rolled blanksoverlap or extend over the backbone or spine 9" thereof, and sometimes stick together. The stuck together portions should be separated to facilitate removal of the binder from the mandrel 5. The edge 119 of the plate 109 helps in this respect. To this end, the edge 119 of the plate is positioned above the end of the ramp 106 a distance appreciably less than the diameter of the mandrel rod, approximately one-half of the tube diameter, so that the ends of the fingers 9' may be brought above the edge 119 and over that edge by simply rotating the assembly of the mandrel and the binder clockwise as viewed in Fig. 5. Thus, the rod and binder thereon are in position to be acted upon by the beveled edge 119 to separate the fingers from the subjacent portion of the binder.

In compliance with the requirements of the patent statutes I have here shown and described a preferred embodiment of my invention. It is, however, to be understood that the invention is not limited to the precise construction here shown, the same being merely illustrative of the principles of the invention. What I consider new and desire to secure by Letters Patent is:

1. Apparatus for rolling tubular objects from relatively fiat blanks comprising a pair of shiftable bands, one immediately above the other, means forming a bight only in the upper of said bands which bight extends upwardly and at least part way around a mandrel placed upon said upper band, and means for shifting the same linearly together in a direction to carry a pliable blank placed on the upper band beneath and around said mandrel, said bands during the shifting thereof being in mutual contact at points directly beneath said mandrel to inhibit movement of the mandrel away from the bight.

2. Apparatus for rolling tubular objects from relatively flat blanks comprising a pair of flexible shiftable bands, one above the other, bight-forming roller means positioned between said bands, means for moving said bight-forming means into engagement with the upper band and for carrying the upper band over a mandrel positioned on said upper band to form a bight or bend therein, means for shifting the bands linearly in a direction to carry a pliable blank placed on said upper band under and around said mandrel, means keeping said bands taut, said bands during the shifting thereof being in mutual contact at points directly beneath said mandrel.

3. Apparatus for rolling tubular objects from relatively flat blanks comprising: a first band, a second band, means for supporting and distending said bands adjacent one another, means for creating a bight in said first band and for carrying said bight part way around a mandrel that is positioned in contact with the side of said first band which faces away from said second band, said second band being in contact with the first band directly tively flat blanks comprising: a first and a second band, one above the other, a table over which said bands extend, means for automatically successively feeding maridrels onto a portion or the upper band which rests on said table at a point constituting a rolling station, bight-forming means, means for automatically moving said bightforming means upward to carry the upper of said bands part way around a mandrel at said rolling station, means for successively automatically feeding relatively fiat blanks onto said upper band and in a position to pass under a mandrel over which the bighted band extends, means for eliminating slack in said bands, and bandmoving means for shifting said bands linearly together and in the same direction following the feeding of a mandrel and a blank to said rolling station, said direction being such that the movement of the upper band carries the blank around the mandrel at said rolling station.

References Cited in the file of this patent UNITED STATES PATENTS 1,415,337 Grover May 9, 1922 1,742,039 Lowry Dec. 31, 1929 2,403,644 Emmer July 9, 1946 2,686,932 Zaleski Aug. 24, 1954 2,728,952 Borushko Jan. 3, 1956 FOREIGN PATENTS 687,873 Great Britain Feb. 25, 1953

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