US3443535A - Tufting machine pattern means using infrared radiation detectors - Google Patents

Description

M y 3, 969 R EELUSON Em. 3,442 535 TUFTING MACHINE PATTERN MEANS USING INFRARED RADIATION DETECTORS Filed March 28, 1966 QoNALP E. ELL/50H TENN FRI'QHARD mvsmbas:

prIZM ArraKuEY United States Patent 3 443 535 TUFTING MACHlNE PA fTERN MEANS USING INFRARED RADIATION DETECTORS I Ronald E. Ellison, Langho, and John Pritchard, Rishton,

U.S. Cl. 112-79 3 Claims ABSTRACT OF THE DISCLOSURE A device for controlling a supply of yarn to the needles of a pattern-producing tufting machine comprising a pattern moved synchronously with the material made by the machine, and having infrared reflecting and absorbing areas, a row of lamps located to supply said pattern with infrared radiation, light guides positioned between said lamps and said pattern, filters for passing only infrared radiation, positioned between said light guides and said lamps, a plurality of infrared sensitive cells and means mounting said infrared sensitive cells in said light guides adjacent said pattern, whereby infrared light passes through said light guides and is reflected from said infrared reflecting areas into said infrared sensitive cells.

Our invention relates to tufting machines for making carpets and like textile articles, and has for its object the provision of means for producing a pattern effect. The said effect consists in the production of tuft loops of different lengths, and may include the production of a coloured pattern.

It is known to provide each yarn or a group thereof with an individual control for effecting the length of each loop made by the needles, the control being derived by a photocell such as a phototransistor provided for each yarn or group, a row of such cells being located on one side of a translucent drum having an opaque pattern thereon, with a light source inside the drum, which is rotated at a predetermined rate relative to the photocells so as to control the tufts produced in accordance with the pattern. This arrangement has the disadvantages that the pattern drum must be shielded from room light, and that the energy falling on each photocell is relatively small. These devices are disclosed in U.S. Patent No. 3,103,187 issued to W. W. Hammel, Jr., on Sept. 10, 1963 and U.S. Patent No. 3,262,163 issued on Sept. 13, 1966 to I. O. Erwin, Jr., et al.

We propose to avoid or reduce these disadvantages by the use of infrared radiation for pattern control, rather than visual light. By this means, a considerably greater quantity of energy is available for control purposes, and the system becomes less liable to disturbance by incident light, such as daylight, which usually has a low infrared component.

In an embodiment of our invention, a tufting machine with individual or group needle control is provided with a pattern of infrared reflecting and infrared absorbing areas, the pattern being in the form of an endless band carried between two forwarding rollers. A line source of infrared radiation, which may be a row of ordinary small electric light bulbs, is located near the band, and a row of infrared responsive photocells is also thus located. The said cells or lamps may be provided with infrared filters, as this is advantageous in preventing interference with pattern control by stray light. Each photocell is connected to an implifier-rectifier the output of which operates a Patented May 13, 1969 control mechanism operating on one or more yarns, to control their tuft lengths.

In operation, the pattern is traversed past the photocells at a speed commensurate with the rate of action of the needles of the machine, thus forming a pattern of long and short loops. The amplifiers may be adapted to exercise their control function either in the presence or the absence of infrared reception, so that the pattern effect on the needles can be reversed.

Finally, the pattern may consist of areas of infrared transmitting and infrared absorbing materials, with the photocells energised by radiation transmitted through the pattern 1 in which case the infrared-source is located inside a pattern drum round which the pattern is laid.

According to our invention, a tufting machine is provided with a pattern constructed to transmit or reflect infrared radiation in pattern-defining areas, the said pattern being moved past a source of infrared radiation and a plurality of infrared sensitive photocells each of which exercises a control function on one or more yarns.

Reference should now be made to the accompanying drawings, in which:

FIG. 1 is an end view of a pattern control device according to our invention, and

FIG. 2 is a portion of a pattern.

From FIG. 1 it will be seen that a pattern control device comprises an endless band pattern I wound round two rollers 2, 3, one of which is driven (No. 2), the other being a tensioning or jockey roller. Above roller 2 is a radiation conductor 13, drilled to take a plurality of photocells such as 4, these having a maximum sensitivity, to infrared radiation. The cell drillings have Walls which allow radiation from only a small portion of the pattern surface to be seen by each cell, and the drillings may be lined with a polished material or have a smooth surface to prevent stray radiation reaching the photocells.

Each photocell is connected by wires 5 to an amplifier which in turn operates a valve or relay controlling pattern making on the machine with which the device is associated.

At the upper end of the guide 13 a number of electric lamps 6 are located. The lamps have reflectors 7, and a filter 8 is located between them and the light guide. This filter has a pass band for wavelengths between 0.7 and 1.1 microns (7,000-11,000 Angstrom units), so that only infrared radiation reaches the pattern and the photocells. The light emitted by lamp 6 passes through the passage 9 of the radiation conductor 13 and is reflected from the pattern belt 1 back to the photocells 4.

The pattern itself consists of an endless band made to a suitable scale. Its surface (FIG. 2) has areas 10 and 11, the area 10 being of smooth material which has a high reflectivity coefficient for infrared radiation, and area 11 is of rough material, with a fibrous or broken surface, have a low coeflicient. Surface 10 may be smooth white glazed paper, and surface 11 may be crepe paper stuck on surface 10.

In order to ensure accurate action of the photocell devices for all kinds of pattern, we arrange one photocell so that it always views a maximum reflection band left at one end of the pattern. This photocell is conncted via a feed-back circuit to the current supply to the lamps, the circuit being such as to maintain a constant value of the reflected radiation intensity, so that if a pattern is changed for another, or if its maximum reflectivity changes with use, the illumination is adjusted to compensate for the change.

Although the invention has been described in connection with a reflective pattern it should be understood that a pattern with transmitting and opaque areas may be used, in which case it may be wrapped round a drum with the light source and filter located inside the drum.

It is preferable to construct the lamp assembly as a separate unit and to provide a fan to move convected or conducted heat so that the pattern receives only radiated energy conducted along the guide 13.

What we claim is:

1. In a tufting machine for producing patterned fabrics comprising a plurality of needles each supplied with yarn, means for controlling said supply of yarn to said needles, said means being a pattern controlling device in cluding: a pattern moved synchronously with the material made by the machine, and having infrared reflecting and absorbing areas, a row of lamps located to supply said pattern with infrared radiation, light guides positioned between said lamps and said pattern, filters for passing only infrared radiation, positioned between said light guides and said lamps, a plurality of infrared sensitive cells, means mounting said infrared sensitive cells in said light guides adjacent said pattern, whereby infrared light passes through said light guides and is reflected from said 2. In a tufting machine as claimed in claim 1, infrared radiation-responsive cells being located so as to receive radiation from a maximum radiation area of said pattern.

3. In a tufting machine as claimed in claim 1, in which said pattern consists of an endless band with smooth and rough pattern-defining areas.

References Cited UNITED STATES PATENTS 2,483,138 9/1949 Helmer. 3,103,187 10/1963 Hammel 1l279 3,163,758 12/1964 Treacy. 3,166,675 1/1965 Dedden et a1. 3,225,191 12/1965 Calhoun. 3,272,163 9/1966 Erwin et al. 112-79 3,323,103 5/1967 Shaw et a1.

infrared reflecting areas into said infrared sensitive cells. 20 JAMES R- B ER, Primary Examin r.

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