US 3911549 A
A tubular member having at least one bulbous formation along the length thereof such as in the case of a stanchion, the bulbous formation being covered by a preferably rigid element which conforms in shape to the bulbous formation.
Claims available in
Description (OCR text may contain errors)
[4 1 Oct. 14, 1975 United States Patent [1 1 Herr I m m .t u u in? eHk M nx RWMMH 9245 3 455567 wwwmww ww wwu 276493 02 4062 7 25 5426 .W 9O 7 3 1 222 233 m N b O m m C a d A h M T O S s A m n t H a m 2 mm m m I d o E n v h a F .I F m w u 7 0 PS M L w e m m mm w m S. w M A I A 1 4 5 3 5 7 7 l XXBXXX U Wolverhampton, gland FOREIGN PATENTS OR APPLICATIONS Dec. 27, 1973 Appl.No.:428,626
Primary ExaminerCharlie T. Moon Attorney, Agent, or Firm-Mason, Fenwick & Lawrence No, 289,972, Sept. 8, I972,
ABSTRACT A tubular member having at least one bulbous formation along the length thereof such as in the case of a the bulbous formation being covered by a rigid element which conforms in shape to the bulbousformation v, nl .m w 3 n E U a m. 5. l 42m2 4874 W31 7/ 250. ;8 322 ,2 Q BB; 5 9/ n4. 2 3 2 QIW A W2 2 25 u .9 n B 2 H "5 n...nn8 7 u 2 "0 "I"; 5 m 2 MW ut m Mm Wm: H 2 l .f C I05 dM SI M U .mFZ T od 5 55 [l References Cited UNITED STATES PATENTS 3 Claims, 2 Drawing Figures 548,998 Mannesmann.................. 285/222 x U.S. Patent Oct. 14, 1975 filed Sept. 18, 1972, now abandoned.
METHOD OF FORMING A S'IACIIION ASSEMBLY This-is a divisionfof application SerfNo.
This invention relates primarily to stanchio'ns and the I like supports for rails such as hand and knee rails, but
. suitable diameter in the enlar'ged bulbous portion.
Various methods have been proposedfor. enlarging the stanchionat its point support. One method provides for thestanchion whe heated at this. point and then expanded undent he actionof a high gas pressure -while the stanchion is rested between co act'ingfdies.
The stanchion expands toassume, completnentarily the profile of the dies. 1 l
This method suffersfrom thedisadvantageithat-the piping from which the stanchions are manufactured is not suitable-for such expansion"and-there is a high loss through bursting of the expanded stanchion wallspThis is a particularly serious problem if two or more enlargements are to be provided on the same stanchion,* as bursting may occur when the final enlargement is being carried out, resulting not only in loss of material but time and effort.
In order to overcome these difficulties, other methods have been proposed. One method provides for sec tions of suitable piping to be spun and then developed to a funnel shape at one or more of the pipe extremities. The expanded extremities of two pipes are then brought together and welded according to known techniques to provide the bulbous formation. This method is costly not only because of the need for welding by skilled, or at least, semi-skilled operators, but also because a finishing operation is required.
In another method, discs are shaped into hemispherical formations which are then butt-welded together. Tubes are then welded to opposite sides of the bulbous formation so formed. This method sufiers from the same disadvantage mentioned above.
An object of the present invention is the provision of,
cover element to be either a deformable plastics element or a rigid bulbous element.
According to the present invention a method of forming a bulbous portion on a tubular member includes the steps of providing a separate hollowbulbous element having at least one hole in the wall thereof, passing an end ofa tubular member into or through the hole or holes in the element and causing the section of the tubular member enclosed by the bulbous element i ex'pan'vd intoconta ct with the inner walls of the element.
Preferably expansion tak'espla cefin the cold by use of known techniques. Preferably also the bulbous elements are formed by die-forming short, lengths of pipe in the cold to the desiredshape.
chio'n' according to the invention; and
By way of example, preferred forms of the "invention willnow be described as applied to the manufacture of stanchio'ns, refer'ence being made to the accompanying drawings in which: v k g 7 FIG. 1 is a section through a partly-completed stan- FIG. 2 is a perspective view of a bulbous element employed in carrying the invention into effect.
Bulbous elements 1 are firstly cold formed in a pair of complementary hemispherical dies through which a mandrel passes, the elements being formed from prede- .termined short lengths of pipe having an external diameter roughly equal to the ;diameter of the}: completed bulbous elemenLjThe mandrel is slightly larger in diameter than the pipe to be used fonthe st anchion sand thus defines two opposed holes throughv the resultant I spherical elements.
In'the next operation one or m ore o'f the above bulbous elements 1 are slippedover a pipe .of desired length and positioned at the points where rails are tobe 4 supported thereby. Thus in the stanchionlexample shown in FIG. one bulbous. element ,1 is positioned midway along the length of the pipe andone towards Q jts extremity. The pipe is then suitablyelamped in the confines of dies which fit neatly over the bulbous elements simply to prevent these from becoming deformed and which support the outside surface of the pipe between the bulbous elements. One end of the pipe is sealed off by means of a mandrel and a pressure is applied to the other end through known ram means to cause the portions of the pipe within the bulbous elements to expand into contact with the inside surface of said bulbous elements.
Whilst the above-described expansion operation may be effected as described, it has been found that it is advantageous to provide a deformable inner liner to the pipe for this operation. Thus, a polyurethane tube or rod is preferably inserted into the pipe prior to the ex-- pansion operation and this assists in the sealing of the one end of the pipe and the distribution of the pressure on the pipe walls. If such a liner is used, it is removed after the expansion operation.
Alternatively, deformable metal plugs may be located in the pipe in the portions within the bulbous ele* ments and these are then caused to expand the pipe by means of suitable plungers. The metal which is a low melting point alloy may be melted out for reuse.
The bulbous elements are now positively locked in position and the stanchion is ready for further treatment.
It will be appreciated that the top end of the stanchion so formed remains open. This can be closed off in a number of ways. The bulbous elements may thus be formed with one hole approximating the exeternal diameter of the pipe and the other diametrically opposite holes having a much smaller diameter. In this case the pipe does not extend through the bulbous formation but bears against the interior walls of the formation in the zone of the smaller hole. The smaller hole is then closed off according to conventional methods, for instance, by welding. In another method of closing off the upper end of the stanchion, a disc is pressed out and welded in position on top of the pipe; the discs outer face forming a continuation of the outer surface of the bulbous element..This latter method is illustrated in 7 FIG. 1, the disc being numbered 3.
a hole is formed in them, an unduly weakened stan-' chion does not result. It may be that expansion, according to prior art methods, takes the walls to the stage where they border on bursting. This is overcome in the present invention in which the pipe walls do not have to be expanded as far as would have been the case had no bulbous elements been provided. In this way, it is felt that the fraction of pipes bursting during the expansion operation will be cut down appreciably.
Many forms of the invention exist and the above description is therefore given by way of example only. Al
though preference is given to an expansion operation employing polyurethane, doubtless other plastics material and rubbers could be used. It is envisaged that sand or even lead billets may be employed. Although cost requirements provide for a cold expansion process, the invention is not limited to thisand under certain conditions it may be found advantageous to expand the metal while in a heated condition. The bulbous formations may be formed en masse as set out above from a length of pipe or may be formed singly.
Whilst it is preferred to use a rigid cover element for the bulbous part of the stanchion pipe, in some cases it may be sufficient to provide a deformable cover over the bulbous portions simply to hide any burst areas. Such a cover could simply be a plastics or rubber sleeve over the bulbous portions.
The invention therefore provides a simple method and means for avoiding the necessity of disposing of burst stanchion pipes.
I claim: 1. A method of forming a stanchion'assembly having a strengthened joint for a horizontal rail member comprising the steps of providing a separate hollow bulbous element having at least onehole in the wall thereof,
passing an end of a first tubular member into the hole in the bulbous element, expanding the section of the I first tubular member enclosed by the bulbous element into conforming contact throughout with the inner surface of the bulbous element, forming an opening at an angle to the first tubular member through the bulbous element and the first tubular member to receive a sec- 0nd tubular member, and passing the second tubular. member through said opening to form the horizontal 1 rail member of a stanchion assembly.
2. A method as claimed in claim 1 in which the bulbous element is a rigid element.
3. A method as claimed in claim 1 in which the expansion is carried out in the cold state.