US2956300A - Web tensioning and cleaning apparatus - Google Patents

Description

Oct. 18, 1960 F. J. BRUNO 2,956,300

WEB TENSIONING AND CLEANING APPARATUS Filed Sept. 17, 1956 2&4,"- w w United WEB TENSIONING AND CLEANING APPARATUS Filed Sept. 17, 1956,-Ser. No. 610,129

4 Claims. (Cl. 15-306) The invention relates -to the control of tension and cleaning :of a running web or material such as paper, fabric, plasticor other material run or processed from a roll.

It further relates to a web tensioning and cleaning device which improves the surface condition of the Web by removal of dirt, lint or other foreign matter so that the subsequent printing or other processing of the web is greatly improved and the Web tensioning function is rendered more continuously accurate.

Objects and advantages of the invention will be set forth in part-hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the :same being realized and attained by means of the instrumentalities and combinations pointed'out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combination and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention and, together with the description, serve to explain the principles of the invention.

The invention described herein has for one of its objects the provision of a device which will clean a running web of paper, such as is fed to a printing press, and maintain adesired tension in the web as it is drawn from a supplyrroll into and through a processing machine, such as a printing press, whereby spoilage, breakage or misregister is eliminated when a new supply roll is substituted for an exhausted roll, or slack appears in the running web due to distorted rolls or roll splices.

Another object of the invention is to provide a web tensioning and cleaning device which will remove continuously the surface dirt, lint or other foreign matter from the running web so that it cannot accumulate sufliciently to interfere either with the tensioning function of the device or the proper high quality processing or printing of the web itself.

A further object of the invention is the provision of a web tensioning and cleaning device which may be manufactured at low cost, be capable of easy installation on existing web processing or printing machines and which permits of quick and easy adjustments to attain and maintain the desired web tensioning regardless of the diameter of the web roll and substantially regardless of the web speed.

Generally considered the device consists of a hollow bar or head structure having a rectangular cross section shape in the order of a few inches and a length the same or only slightly greater than the Width of the Web which the device is to control. The hollow interior of the bar or head structure is divided into two pairs of parallel, longitudinal chambers. Each pair of chambers has one of its component cavities in communication both with the other cavity and with the exterior of the bar through one wall thereof. The two exterior ports, that is one from each pair of chambers, are in the same wall of the res Patenr if)? Patented Get. 18, 1960 hollow-barand closely adjacent each other, being separated onlyby a-round rod which forms-one side-of each port. The round rod is provided with numerous transverse slots in its outwardly facing side which serve as partial connections from one exterior port to the other.

One pairof bar chambers is connected by a conduit and control valveto anysource of suction and theother pairissimilarly connected to a source of air supply under pressure. If desired, the source of suction and air supply may be the intake and exhaust of a conventional motor driven blower.

Inoperation-and-assuming the web to be running vertically upwards from a supply roll, two of the .hollow bars are preferablyused and supported one oneither side and transversely of the web :so that the ported wall of each bar just touches the web. The bars are spaced apart vertically in the order of a few inches.

In the arrangement as thus described, the upper pair of chambers of each hollow bar is connected to controllable suction and thelower pair to controllable air supply under pressure. The air supply delivered to the lower chambers of each bar is adjusted so that the stream of air striking the web from the lower port and flowing past the slots in'the round rod to the suction chambers has the necessary velocity to dislodge and transport the surface dirt and lint carried by the web. Concurrently, a greater degree and .volume of suction in the upper pair of chambers of each bar is preferably maintained and adjusted to produce a partial vacuum therein when the web is against the bars ported wall. The degree and volume of suction compared to the degree and volume of air supplied determines the amount of friction or drag determines and maintains any'desired tension in the running web as it is pulledthrough the machine by feed rolls,

and by the presentation of a continuously cleaned web surface to the frictional area of the device a very sensitively adjustable and accurately maintained web tension is attained.

Of the-drawings:

Figure 1 is a fragmentary side view partly in section and partly diagrammatic of a pair of hollow bars embodying the invention and arranged transversely against a web;

Figure 2 is a plan view of one of the tension controlling hollow bars as seen along the line -22 of Figure 1; and

Figure 3 is a .side elevation of one of the hollow bars showingthe ported wall and slotted rod as viewed along the line 3-3 of Figure 1.

of the invention illustrated in the drawings:

A Web W, such as newsprint material, passes upwardly between horizontally disposed, vertically spaced, hollow bars or head structures 10 and 12, then over a roller R into a processing machine or printing press (not shown). Feledrollers F serve to draw the web W from the supply r0 1 S.

.Since the hollow bars 10 and 12 are similar in construotion, a description of one will be deemed sufiicient and the same reference characters will be applied to comparable parts of each bar.

The tension controlling hollow bar 10 is provided with an upper pair of chambers consisting of a suction manifold 14 and a suction chamber 16, and a lower pair of chambers consisting of an air supply manifold 18 and and airchamber 20. All four of the chambers 14, 16, 18 and 20 are closed at their ends -by cover plates 22, Figures 2-3, which are secured oneachend of the hollowbar 10. One end of the suction manifold 14 is connected by a conduit 24 to a suction device such as the intake port of a blower (not shown), and a suitable valve 26 is provided in the conduit 24 to control the degree of suction. The suction chamber 16 is to one side of and parallel to the suction manifold 14 and communicates therewith by a plurality of suction equalizing holes 28. The holes 28 by suitable size and distribution serve 'to provide an even distribution of suction in chamber 16 regardless of the suction conditions in the manifold 14.

Of the lower pair of chambers the air manifold 18 is provided at one end with a conduit 3!} which connects it to a source of air supply under pressure (not shown) and a suitable valve 32 in the conduit line serves as controlling means for regulating the air delivered to the air manifold 18. The air chamber 26 is beneath the suction chamber 16 and is connected to air manifold 18 by a plurality of air pressure equalizing holes 34. The holes 34 by their suitable size and distribution serve to provide an even distribution of air pressure in the air chamber 26 regardless of the pressure condition in the air manifold 18.

A round rod 36 is mounted on the outer edge of a common wall or partition 38 which divides the suction chamber 16 from the air chamber 20. Mounted on the top wall of suction chamber 16 is an angle strip 40 the depending, smooth vertical flange 42 of which forms the outer side wall of the suction chamber. The flange 42 terminates just short of the rod 36 thereby forming a narrow slot or port 44 between the suction chamber 16 and the exterior of the hollow bar 10. Similarly a port 46 is formed between the air chamber 20 and the exterior of the bar 10 by the upwardly extending, smooth flange 48 of an angle strip 50 which is secured to the bottom wall of the air chamber 20. Flanges 42, 4S and rod 36 are preferably parallel with each other and the outer edge of rod 36 is preferably tangent to a line connecting the outer faces of the flanges 42 and 48.

A series of spaced, shallow, transverse slots 52 are provided in the outwardly facing rod 36 so that each slot constitutes a passage for a high velocity air stream from the port 46 into port 44 when the web W lies against the angle strip flanges 42 and 48. It is through these slots 52 that surface dirt and lint from the web W is carried into the suction chamber 16, through holes 28, suction manifold 14, conduit 24 and valve 26 to a disposal point (not shown).

' The angle strips 40 and 50 and their flanges 42 and 48 are preferably straight and made of a material having trictional characteristics relative to the material of the 'web W so that pressure of the running web against the flanges 42 and 48 will cause a drag to develop on the web which is proportional to the degree of suction applied in suction chamber 16. This drag in relation to the force pulling the web W into the machine is the means whereby the desired tension in the running web W is created. Variation of the drag by varying the settings of the valves 26 and/ or 32 will vary the web tension to the desired degree.

As an example of material from which to make the angle strips 40 and 50 it has been found that paper stock such as newsprint is the web material the strips may be made of the plastic material known as Teflon. This material appears to have a greasy surface and has the desirable property of not having dirt adhere strongly thereto.

The valves 26 and 32 are preferably adjusted so that the capacity of the suction system, as regulated by valve 26 is always more thanenough to remove all of the air supplied through valve 32, thereby maintaining the air pressure against the web W within the chamber 16 at considerably less than atmospheric pressure while the pressure within the air chamber 20 is preferably maintained only slightly less than at atmospheric pressure.

However, at times it may be desirable to adjust the degree of suction applied to chamber 16 so as to maintain .4 a negative pressure (less than 1 atmosphere) within the chamber 16, While a slight positive pressure (greater than 1 atmosphere) is maintained within the chamber 20, thereby allowing air to escape along the elongated port 46, carrying dust or lint with it, while additional dust and lint are removed by the high velocity air passing through slots 52. j

The tension producing and cleaning hollow bars 10 and 12 may be adjustably mounted, both angularly and horizontally, adjacent the running web W by any convenient means. As illustrated each bar 10 or 12 is supported in an adjustably fixed position on a tubular member 60 which may be a part of the machine frame or mounted thereon. At suitable intervals on the member 60 plates 62 are secured as by U-shaped clamp bolts 64. A block 66, depending from each plate 62 carries a threaded rod 68 which is adjustably fixed in the block 66 by check nuts 70.

Hanger brackets 72 are secured on the hollow bars 10 and 12 at spaced intervals and attached to the rods 68 by clamp screws 74. Thus the hollow bars are angularly adjustable around the screws 74 and horizontally adjustable in relation to the web by means of the rod 68 and check nuts Operation After the hollow bars 10 and 12 have been adjusted to a desired position in relation to the running web W the suction control valve 26 and air control valve 32 associated with each bar are set so that the vacuum in chamber 16 overcomes all tendency of the air stream from chamber 20 to force the web away from the flanges 42 and 48, the air stream being sufficiently strong to dislodge the dirt, line or other foreign matter on'rthe web and carry it into the suction chamber. Having adjusted the valves 26 and 32 as just described further adjustment of the suction valve 26 to increase the vacuum will increase the drag on the Web until the desired amount of tension in the web is obtained.

Alternatively, the valve 26 may be adjusted so that the suction within the chamber 16 is sufliciently strong against the paper web W at the elongated port 44 to cause the web always to be sucked against the slotted rod 36 and the flange 42, while the air pressure within the chamber 20 is sufficiently great to allow air to force the web slightly away from the elongated port 48 and allow air to escape across flange 48.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom, within the scope of the accompanying claims, without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. Web tensioning and cleaning apparatus comprising an elongated head structure extending across the direction of web travel, said head structure in transverse section providing two chambers disposed along the direction of web travel and having a common dividing wall, said chambers being symmerically positioned with respect to said dividing wall and each chamber having a relatively long and narrow port extending substantially from edge to edge of the web to be cleaned and tensioned when the head is positioned against the surface of the running web, said chamber extending laterally of the port and having strips lying against said web functioning as chamchamber whereby the surface of the Web is held against 5 said head and tensioned thereby while the web is cleaned by the air passing from the air-supplied chamber past said rounded member .to the suction chamber.

2. Web tensioning and cleaning apparatus according to claim 1 in which the rounded member has a portion in said plane and the slots on said rounded member extend from the side where air is supplied to a portion of the surface of said rounded member slightly beyond said plane where the web is tangent to said rounded member.

3. The construction according to claim 1 wherein said chambers having their ports adjacent the dividing wall defined by long strips extending toward but stopping short of said rounded member, said long strips defining said narrow ports being of Teflon, said Teflon having a low coeificient of friction and not retaining dint.

4. The construction according to claim 1 wherein said chambers having their ports adjacent the dividing wall defined by long strips extending toward but stop- 6 ping short of said rounded member, said strips defining the narrow ports being of Teflon and wherein said slots in said rounded member are oriented to extend from the air supply chamber to the suction chamber, said Teflon having a low coefiicient of friction and not retaining dim.

References Cited in the file of this patent UNITED STATES PATENTS 1,196,437 Doyle Aug. 29, 19.16 1,196,439 Doyle Aug. 29, 1916 2,082,411 Merrill June 1, 1937 2,227,298 Cranmer Dec. 31, 1940 2,875,846 Yonkers Mar. 3, 1959 FOREIGN PATENTS 18,224 Great Britain 1912 291,920 Great Britain J June 14, 1928 755,780 Great Britain Aug. 29, 1956

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