Sewing – Special machines – Darning
Patent
1992-09-17
1994-06-28
Crowder, Clifford D.
Sewing
Special machines
Darning
112307, 112155, D05B 300, D05B 2700
Patent
active
053237234
DESCRIPTION:
BRIEF SUMMARY
This invention relates to sewing machine assemblies, and relates particularly but not exclusively to sewing machine assemblies for the sewing of overlapped edges of thick textile material, such as needle felts in the order of a thickness of 6 mm or more.
It is known to utilise tubular felt materials as tubular linings for underground pipelines and passageways, for example as set forth in British Patent Specification 1449455, and in order to construct such tubular lining materials, a flat web of textile material typically a needled felt is folded into tubular form until the free edges overlap, and then they are sewn together by an appropriate sewing machine so that the material will retain its tubular form. As these webs are formed into long sections of tubular material, it is usual to keep the sewing machine stationary, and to feed the web past the machine in order to effect the stitching.
In fact, in order to avoid side loading on the sewing needle, it is usual to advance the web by means of a dog feed arrangement so that the web is in fact stationary as the needle penetrates the material and then leaves same in order to form the stitch, following which the material is advanced and the stitch feeds it and so on. This method of sewing tends to slow down the process, and to give rise to inertia problems and inefficiencies.
The present invention provides a sewing machine assembly whereby this disadvantage can be overcome, and in accordance with the present invention, the sewing machine is mounted so that it is capable of movement in the direction of feed of the workpiece (e.g. a needle felt web) past the sewing machine so that the sewing machine is travelling at the same speed as the workpiece as the machine needle enters and leaves the workpiece, said sewing machine being connected to a drive mechanism for the oscillation of same to provide the sewing machine with a forward stroke and a return stroke, and within the forward stroke the sewing machine is accelerated up to the speed of movement of the work piece before the needle penetrates the work piece, and is decelerated to zero after the needle leaves the work piece upon completion of the stitch.
Preferably, there is control means for controlling the said acceleration and deceleration depending upon the speed of movement of the workpiece.
Said control means may embody a microprocessor for varying the said acceleration and deceleration depending upon the said speed of movement of the work piece, which preferably is constant.
The movement of the sewing machine may be controlled by means of two cams so that during one cycle of operation, the forward stroke of the sewing machine is effected over an angular extent of the cycle of 270 degrees, whilst during the remaining 90 degrees the sewing machine is moved back to the beginning of the forward stroke position.
A drive motor may be used for driving said cams, and the sewing machine is preferably mounted on linear anti-friction bearings.
The sewing machine is preferably adapted to sew overlapped edges or face to face edges of needle felt material which is either plain felt or is felt provided on one side with a synthetic resinous material impermeable coating such as polyurethane.
The sewing machine of the assembly may be of commercially available construction.
An embodiment of the present invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, wherein:
FIG. 1 is a diagrammatic side view of a machine for forming tubular lining material;
FIG. 2 is a part-sectional end view of a sewing machine head for sewing the outer layer of material in the arrangement of FIG. 1;
FIG. 3 is a view similar to FIG. 2, but showing the sewing machine head which is used for sewing the inner layer of the lining material in the arrangement of FIG. 1;
FIGS. 4, 5 and 6 respectively show a part-sectional side view, a part sectional end view and a plan view of a sewing head and its mounting, the sewing head being either a sewing head of FIG. 2 or the sewing head of FIG. 3;
FIG. 7 is a d
REFERENCES:
patent: 260130 (1882-06-01), Smith
patent: 1103587 (1914-07-01), Houston
patent: 1731001 (1929-10-01), Gail
patent: 4102283 (1978-07-01), Rockerath et al.
patent: 4327653 (1982-05-01), Blessing
patent: 4343998 (1982-08-01), Mori
patent: 4413580 (1983-11-01), Moyer et al.
patent: 4848252 (1989-07-01), Ciucani
patent: 4883006 (1989-11-01), Marii et al.
Crowder Clifford D.
Insituform (Netherlands) BV/SA
Lewis Paul C.
Philpitt Fred
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