US 3863857 A
An improved leaf-type air shaft wherein one leaf member, of a plurality of expansible leaf members, is fixed on the exterior of the shaft, with a lateral edge portion forming a fixed jaw to cooperate with a trapper bar movable on a row of buttons arranged along the length of an air bladder within the shaft, the trapper bar forming a clamping means suitable for holding the leading edge of paper to be rolled up upon the shaft. The row of buttons itself may form the movable clamping means. The fixed leaf makes the shaft asymmetrical when the other leaves are retracted.
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Description (OCR text may contain errors)
llnitew States Patent Smith Feb. 4, 1975 1,051,352 12/1966 Great Britain .1242/72  Inventor: Geoffrey Smith, Nashua, NH. Primary Examiner john Huckert Assignee; Nim-cor Inc. Nashua Assistant Examiner-John Jillions  ed Apr 2 3 Attorney, Agent, or Firm-Pearson & Pearson  Appl. No.: 346,769
 ABSTRACT  US. Cl. 242/72 B, 242/74.l  Int. Cl B65h 75/24, B65h 75/28 An improved leaf type air Shaft wherein one leaf  Field Of Search 242/74.1, 74.2, 74, 78.3, member of a plurality f expansible f members, i 242/72 72 fixed on the exterior of the shaft, with a lateral edge portion forming a fixed jaw to cooperate with a trap-  References C'ted .per bar movable on a row of buttons arranged along UNITED STATES PATENTS the length of an air bladder within the shaft, the trap- 1,845,526 2/1932 Spence 242/74.2 X Pe bar forming a clamping means suitable for holding 2,351,894 6/1944 Allardt 242/74.l X the leading edge of paper to be rolled up upon the 2,352,042 6/1944 Linde.... 242/74.1 X shaft. The row of buttons itself may form the movable 2,723,805 11/1955 Herr 242/72 clamping means The fixed leaf makes the shaft asym- 2,950,071 8/1960 Tidland 242/72 B metrical when the other leaves are retracted.
FOREIGN PATENTS OR APPLICATIONS 8,537 l0/l955 Germany 242/72 9 Claims, 4 Drawing Figures PATENTED FEB 4 75 9 i W on on o I O LEAF-TYPE EXPANSIBLE SHAFT WITH TRAPPER BAR BACKGROUND OF THE INVENTION Expansible leaf rolls, sometimes called leaf-type air shafts, are known in the web-processing art. Usually, they comprise three elongate leaf members each of which has something less than a 120 arc and, when arranged together, form what may generally be considered as the outer cylinder of an elongate roll. These leaf members are spaced from one another and attached to buttons, in turn radially movable by an air bladder within the shaft. Inflating and deflating the air bladder within the cylinder increases and decreases the effective diameter of the shaft, thereby either tightening or loosening a web of paper wrapped about the shaft, or the grip on a core of a roll of paper on the shaft. Such a leaf shaft is disclosed in US. Pat. No. 3,053,467.
It has been a problem to achieve a quick and convenient attachment of paper to these rolls, especially in situations where the paper has a low friction coefficient. Assuring a sufficient wrapping of paper to start winding properly takes time and requires judgement by the operator. Thus it has been desirable to provide an improved means for obtaining the initial attachment of paper to the leaf shaft, one which will not interfere with a prime advantage of the leaf shaft, i.e., assuring easy release of the roll from the shaft after the completion of the winding action.
SUMMARY OF THE INVENTION Therefore, a principal object of the invention is to provide a leaf-type shaft which comprises means to hold the lead end of a sheet to be wound about the shaft, but does so without interfering with the easy release of a roll once the winding has been completed.
Another object of the invention is to provide a leaf type air shaft of the type described which is economical to manufacture and easily operated by semi-skilled workmen.
Other objects of the invention will be obvious to those skilled in the art on reading the instant application.
The, above objects have been substantially achieved by the construction of a leaf-type cylindrical air shaft wherein one of the leaves is positioned permanently in asymmetrical position, i.e., positioned so that it is not subjected to substantial radial movement by the inflation or deflation of an air bladder axially arranged within the shaft, but instead constitutes a jaw fixed in expanded location. Below this leaf, or fixed jaw, is positioned a bar member, or movable jaw member, which is radially moved by increasing or decreasing the pressure in the air bladder. The movable jaw member can thus be moved to grip the lead end ofa web against the stationary leaf or fixed jaw.
ILLUSTRATIVE EMBODIMENT OF THE INVENTION In this application and accompanying drawings, there is shown and described a preferred embodiment of the invention and suggested various alternatives and modifications thereof, but it is to be understood that these are not intended to be exhaustive and that other changes and modifications can be made within the scope of the invention. These suggestions are selected and included for purposes of illustration in order that others skilled in the art will more fully understand the invention and the principles thereof and will be able to modify it in a variety of forms, each as may be best suited in the condition of a particular case.
IN THE DRAWINGS FIG. 1 is a view, partially in section, of a leaf-type air shaft constructed according to the invention;
FIG. 2 is an end view in section, on line 2-2 of FIG. 1, showing the shaft unexpanded;
FIG. 3 is a view similar to FIG. 2, showing the shaft expanded and gripping a tail-end of a roll; and
FIG. 4 is a view similar to FIG. 2, showing the row of buttons serving as the clamping, or trapper, means.
Referring to FIG. 1, it is seen that a shaft 10 comprises an internal expansion chamber 12 formed of an expansible cylinder wall 13 into which fluid, usually air, is passed through an air valve 14 to alternately expand and contract expansion chamber 12, as is desirable.
Mounted along and attached to outer surface 16 of wall 13 are plates 18, which plates serve to support leaf-securing buttons 20. The leaf-securing buttons 20 protrude through holes 21 in intermediate cylinder 22 and are fastened to each of two external elongate leaf members 24 by screws 23. A third elongate leaf member 24fis not attached to any buttons 20, but, as is best seen in FIG. 2, is directly attached to intermediate support cylinder 22 by elongate spacer bars 26. Spacer bars 26 hold leaf member 24fin a fixed radial position, independent of the state of inflation of chamber 12 of inflatable tube 13.
Below and proximate one lateral edge 28 of fixed leaf 24f is an elongate compression bar member 30, which is attached to plates 32 by a row of connecting buttons 34. Bar 30 has a rounded outer head 33 which approximately conforms to a segment of the rounded inner surface 36 of leaf 24]. The edge 28 of leaf 24f, which is proximate bar 30, is curved outwardly and away from bar 30. The adjacent edge 40 of the adjacent leaf 24 is curved downwardly and inwardly toward the compression bar member.
These curved edges form a tapered slit, or mouth, through which sheets 42 of paper, cloth, plastic or other such web materials may be safely positioned into a nip 44 formed by bar 30 and leaf 24f.
In operation, shaft 10 is initially in a deflated condition, that is chamber 12 is sufficiently deflated that leaves 24 outline an inner cylindrical shaft configuration of reduced diameter, while leaf 24f outlines a portion of an outer cylinder. Thus leaf 24f makes shaft 10 asymmetrical when deflated, but symmetrical when inflated. This, of course, is because of the rigid connection of leaf 24f to support cylinder 22 by spacer bars 26. However, deflation of chamber 12 does allow the retraction of trapper bar 30 and causes a nip 44 to be formed between bar 30 and leaf 24f. The paper web is inserted into this nip 44. Thereupon chamber 12 is inflated and the paper web is compressed between trapper bar 30 and leaf 24f. After the web is wound upon shaft 10, it is easily removed therefrom by deflating chamber 12, causing the roll of paper to loosen on the shaft.
It should be noted that a series of apertures 46 in leaf 24f may be provided to form means to visually inspect the position of the paper within the nip. Slightly elongated apertures with index marks 48 are a material aid in assuring the desirable alignment of the paper in nip 44.
it is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which might be said to fall therebetween.
As shown in FIG. 1 the elongate compression bar 30 need not be continuous but may be discontinuous and formed of segments 52 as indicated at 50.
As shown in FIG. 4 the compression means, or elongated clamping means 54 need not be a continuous trapper bar 30, or a discontinuous bar 50, but may consist only of the spaced connector members, or buttons 56 operable as a moving jaw against the fixed jaw formed by the leaf 24]".
1.ln a leaf type air shaft of the type comprising a generally cylindrical outer surface formed of several elongate, radially movable leaf members, an intermediate cylinder having apertures for radially movable buttons and a fluidic expansion chamber arranged axially within said cylinder, said chamber radially moving said buttons to change the effective diameter of said surface formed by said leaves, the improvement wherein:
one said leaf member is immovably supported in fixed radial position on said intermediate cylinder, said member having one axially-extending lateral edge portion spaced from said cylinder and having an inner surface forming a stationary clamping jaw; and
a movable compression means on said shaft, oppositely disposed to said inner surface in said space, and under said lateral edge portion of said one leaf member, said compression means being operably connected through said apertures to said chamber for radial movement by expansion and contraction thereof and said compression means having an outer surface forming a movable clamping jaw serving to hold a sheet against the inner surface of said fixed leaf member when said chamber is expanded.
2. Apparatus as defined in claim 1 wherein:
said compression means is an elongated continuous bar mounted adjacent said one lateral edge of said fixed leaf and said outer surface is generally shaped to conform to the shape of said inner surface of said leaf, both said surfaces being arcuately curved.
3. Apparatus as defined in claim 2, wherein:
said lateral edge of said fixed leaf is curved outwardly and away from said compression bar; and
the next adjacent edge of a movable leaf is curved inwardly and toward said compression bar.
4. Apparatus as defined in claim 1, wherein:
said compression means is one axially extending row of said buttons each radially movable in said apertures in said shaft and collectively forming the said outer surface to form a radially movable clamp.
5. Apparatus as defined in claim 2, wherein:
said compression bar is fixed to the tips of a row of said radially movable buttons.
6. Apparatus as defined in claim 2, wherein:
said compression bar is mounted adjacent one lateral edge of said fixed leaf member; and includes a curved outer face;
said lateral edge of said fixed leafis curved outwardly and away from said compression bar; and
the next adjacent edge of a movable leaf is curved inwardly and toward said compression bar.
7. Apparatus as defined in claim 2, wherein:
said intermediate cylinder includes a recess;
said compression bar, when in retracted position, is
adapted to be partially received in said recess.
8. Apparatus as defined in claim 2, wherein:
said compression bar is elongated but discontinuous and each segment thereof is radially movable and affixed to at least one button, radially movableby said expansion chamber.
9. In an expansible shaft of the type having outwardly movable leaves extending along, and around, an intermediate cylinder, the combination of:
a plurality of said elongated leaves spaced around said cylinder, one said leaf being fixed to said cylinder in asymmetrical position to define a portion of a cylinder outlined when all of said leaves are expanded and having one axially extending lateral edge portion spaced from said cylinder to form a space therewith for receiving an end of a web;
the other said leaves being normally retracted but radially movable outwardly to define said cylindrical outline with said fixed leaf;
elongated clamping means on said intermediate cylinder, oppositely disposed to, and under, the lateral edge portion of said fixed leaf, in said space, for gripping said end of said web against said lateral edge portion of said fixed leaf, said means being radially movable in said space;
and means for moving said outwardly movable leaves and said clamping means radially inwardly and outwardly.