US2724870A - Doffer comb drive and support - Google Patents

Description

Nov. 29, 1955 R, w, vos 2,724,870

DOFFER COMB DRIVE AND SUPPORT Filed July 28, 1950 2 SheebS-Shaet 2 U R @Mem ATTO RN EY United States Patent Oflice 2,724,870 Patented Nov. 29, 1955 DOFFER COMB DRIVE AND SUPPORT Robert W. Vose, West Springfield, Mass., assignor to Chicopee Manufacturing Corporation, a corporation of Massachusetts Application July 28, 1950, Serial No. 176,379

6 Claims. (Cl. 19-106) The present invention relates to a textile carding machine and has particular reference to a new and improved means for supporting and driving the doffer comb employed in such devices. The invention also relates broadly to supporting and driving means for shafts that are subjected to rocking or oscillatory motion.

The operation of a conventional carding machine and its associated doifer comb, dolfer comb support and drive are well known. They are explainedby Hunt in U. S. Letters Patent No. 2,118,975.

In normal operation of the card the doffer comb is vibrated at a frequency of the order of 1600 cycles per minute. Because of this high rate of vibration the mechanisms actuating the comb are subjected to severe mechanical strain in overcoming the inertia load twice each cycle in starting and stopping the doffer comb. Even though the doifer comb actuating mechanism is conventionally maintained under an oil bath within a comb box, maintenance and replacement difficulties are continual problems common in the industry. Then too, power requirements are relatively high. Oil stains on the fabrics occur frequently.

through unavoidable leakage of the lubricant from the comb box, In general, one object of the invention is the provision of an improved support for a rocking shaft that is subjected to oscillatory motion at a very high frequency. More particularly one of the objects of my invention is to provide a new and improved doifer comb drive and support assembly that avoids the difficulties and objectional features inherent in the prior devices. Especially, one object is to store the kinetic energy of the moving comb and its mounting as it is decelerated and stopped and then use this energy to start the parts and accelerate them in the opposite direction. By doing this I need supply to the system only a relatively small amount of energy necessary to overcome friction in and between the members. My invention thereby decreases the load on the driving mechanism during continual operation, and substantially decreases wear, power consumption, noise and lubricating trouble in the comb box. Still another object is to provide a dofier comb support which eliminates the slack, noise and lubricating difiiculties of conventional journal bearings normally employed to support the rotating rocker shaft to which the comb is aflixed.

In the drawings:

Fig. 1 is a diagrammatic perspective view of the front of the card equipped with one form of my invention and stripped of various conventional appurtenances which have no bearing on the present invention;

Fig. 2 is a diagrammatic fragmentary side elevation on an enlarged scale showing the spring system and supporting arrangement used in some forms of the present invention;

Fig. 3 is a plan view of the elements as shown in Figs. 1 and 2;

Fig. 4 is a diagrammatic view similar to Fig. 3 using the second arrangement described being stripped of certain extraneous parts for simplicity; and

Fig. 5 is a side elevation of a helical spring used in a second embodiment of my invention.

Referring to Figs. 1 and 2, the doffer cylinder 10 revolves, bearing a web of fibers on the surface of the card clothing. The fibrous web is engaged by the teeth of the oscillating dotfer comb 12 and stripped from the doffing cylinder. The dofling comb is carried by the supporting arms 13 which are rigid with the rocker shaft 14. The rocker shaft 14 is supported in suitable bearings, one end being journalled in the bearing 16 in the conventional comb box 18.(Fig. 1). A suitable actuating drive (not shown) imparts oscillatory motion to the rocker shaft through a suitable driving mechanism in the comb box 18. As thus far described the carding machine is conventional.

In my invention the end of the rocker shaft opposite the bearing 16 is attached to a novel support and drive mechanism. 'A spring support bracket 20 is secured to a member of the card frame 22. An end of each of two similar leaf springs 24 disposed at right angles to one another is fastened to the spring support bracket 24). The other end of each of the leaf springs 24 is attached to a second spring support bracket 26. The spring bracket 26 is secured to clamp collar 28. Clamp collar 28, in turn, is fastened to the other end of rocker shaft 14. Thus a substantially frictionless support and bearing is provided for the oscillating rocker arm 14 (Figs. 1, 2 and 3). The number of leaf springs used in this novel support arrangement is not significant to the proper operation so long as an axis of oscillation for the rocker arm 14 can be maintained about a line geometrically parallel to the rocker arm and passing through a point through the center of the intersection between the leaf springs. This can be accomplished with a plurality of similar leaf springs intersecting at their midpoints by arrangings them so that all the angles at the point of intersection between adjacent radial spring segments are equal.

The system comprised of the leaf springs 24, and the driven comb assembly and mounting is designed to have a natural frequency of vibration which equals a suitable operatingfrequency of the rocker shaft 14. The conventional actuating mechanism and the leaf springs 24 will then cooperate to put the system in a state of mechanical resonance. In this arrangement a reversible conversion of kinetic and potential energies takes place to an optimum degree. The springs 24 in the relaxed condition yieldingly hold doifer comb 12 in its mid-position. When the machine is at the normal operating speed for which the system is designed, the spring is distorted as kinetic energy of the moving comb 12 and rocker shaft 14 is converted to potential energy of spring tension on an excursion of the comb away from the midpoint. This results in a deceleration and stoppage of the doffer comb 12 at the end of its sweep in one direction. At this point the potential energy stored in the deformed springs begins to become converted to kinetic energy of motion of the moving comb and rocker shaft assembly as these members accelerate in the opposite direction. Energy conversion from potential to kinetic reverses at the midpoint when the springs are once again relaxed. The same action repeats in the opposite direction to complete the cycle of the doifer comb. Thus the interchange of energy between the spring system and the moving parts is to a large degree self-sustaining and the external force supplied by the driving mechanism need not be expended to drive the spring nor to overcome inertia, except for frictional losses resulting in the system.

In another arrangement (Figs. 4 and 5) it has been found possible to obtain the desired mechanical resonance by using a helical spring 30 disposed about the rocker shaft 14 and fastened at one end to the rocker shaft by any suitable arrangement. The other end of helical spring 30 is secured to a member of the card frame 22. The system comprised of helical spring 30 and the driven comb assembly and mounting must, of course, have a natural frequency of vibration substantially equal to the frequency of oscillation of the rocker shaft 14 when the doifer comb is in normal operation. In the latter arrangement both ends of the rocker shaft are supported by any approved means according to the known art, for example, by being journalled in suitable bearings 16 in the comb box 32 and in the member of the card frame 22. In this embodiment the novel supporting arrangement for the rocker shaft is not used.

It will be understood that whatever form of my invention is employed the essential feature is that the spring system has a natural frequency of vibration such that it can be put into mechanical resonance with the actuating mechanism when in normal continual opera tion.

I claim:

1. In a card the combination of a mechanically resonant vibrating system including a dofiing comb adapted to be oscillated between two extreme positions through mid-position, a support for the comb, and plurality of springs for yieldingly holding the comb in mid-position; and driving means for oscillating the comb about the mid-position, said springs, dofiing comb and support being designed to be mechanically resonant and have a period of free vibration equal to the period of oscillation of the driving means.

2. In a card the combination of a mechanically resonant vibrating system including a dofler comb adapted to be oscillated between two extreme positions through mid-position, a rock shaft supporting the comb, a journal bearing supporting one end of the rock shaft, and a pair of mutually perpendicular leaf springs supporting the other end of the shaft, one end of each spring being fixed and the other end of each spring being rigidly secured to the rock shaft to permit oscillation of the shaft against the force of the spring, the springs yieldingly holding the comb in mid-position; and driving means for oscillating the comb about the mid-position, said springs, doffer comb, and rock shaft being designed to be mechanically resonant and have a period of free vibration equal to the period of oscillation of the driving means.

3. In a card, the combination of a mechanically resonant vibrating system including a doifing comb adapted to be oscillated between two extreme positions through mid-position, a rotatable shaft for supporting the comb, and a helical spring surrounding the shaft, the spring having one end fixed and the other end secured to the shaft and yieldingly holding the comb in mid-position; and driving means for oscillating the comb about the mid-position, said spring, doffing comb and support being designed to be mechanically resonant and have a period of free vibration equal to the period of oscillation of the driving means.

4. In a card, the combination of a mechanically resonant driven vibrating system including (1) a dofiing comb adapted to be oscillated between two extreme positions through a mid-position, (2) a rotatable shaft for supporting the comb, and (3) a helical spring surrounding the shaft, the spring having one end fixed and the other end secured to the shaft and, in its relaxed condition, yieldingly holding the comb in mid-position; and driving means for oscillating the comb about the midposition, said driven vibrating system being designed to be mechanically resonant and have a period of free vibration equal to the period of oscillation of the driving means.

5. A dolfer comb mechanism comprising a fixed mounting, a driven vibrating system comprising (1) a comb member and (2) intermediate means, including a resilient mechanism, securing the comb member to the fixed mounting and, in the relaxed condition, yieldingly holding the comb member in an intermediate position for oscillation between two extreme positions, said driven vibrating system being designed to have mechanical resonance at the desired frequency of oscillation of the comb member, and means operating periodically to drive the comb member at such frequency of oscillation.

6. In a card the combination of a mechanically resonant vibrating system including a dofiing comb adapted to be oscillated between two extreme positions through mid-position, a rotatable shaft for supporting the comb, and a spring secured to the shaft; and driving means for oscillating the comb about the mid-position, said spring, driving comb and support being designed to be mechanically resonant and have a period of free vibration equal to the period of oscillation of the driving means, said spring tending to restore said comb to midp'osition during said oscillation.

References Cited in the file of this patent UNITED STATES PATENTS 849,418 Nickerson Apr. 9, 1907 1,085,731 Hafner Feb. 3, 1914 1,332,755 Riedler Mar. 2, 1920 1,469,231 Marbury Oct. 2, 1923 1,493,259 Green May 6, 1924 1,645,794 Bumstead et al. Oct. 18, 1927 1,720,574 Schieferstein July 9, 1929 1,918,456 Dodge July 18, 1933 2,188,060 Robins Jan. 23, 1940 2,202,032 Smith May 28, 1940 2,455,787 Linn Dec. 7, 1948 2,539,081 Hunt et al. Jan. 23, 1951 FOREIGN PATENTS 1,267 Great Britain of 1864 7 470,213 Germany Jan. 11, 1929

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