US 2974687 A
Description (OCR text may contain errors)
March 14, 1961 G. A. MOFETTERS I 2,974,687
DENT FOR LOOM REEDS Filed Aug. 10, 1959 INVENTOR. GEORGE A. M FETTERs B dmbw, LA 4% ATTORNEYS here 13 in a conventional manner. V I apart, parallel reeddents, fbroadlyindicated at 15., are
tates V DENTFOR LooM nnnns This invention relates generally to dents for loom reeds and more particularly to improved dents adapted to reduce friction and static electricity upon the warp thread guided thereby.
All known prior attempts to reduce friction of the dents against the warp threads guided thereby have involved the'use of specially constructed dents in which the cross-sectional configuration of the dents was unusual or involved positioning the dents in the reed frame so that they extend between the warp threads at an unusual angle.
It is the primary object of the present invention to provide improved dents for a loom reed which are adapted to reduce friction and static electricity upon the warp threads guided thereby while utilizing dents having a conventional cross-sectional configuration and maintaining the dents in a conventional position in the reed frame.
It is another object of the present invention to provide friction and static electricityreducing dents for a loom reed byiutilizing a friction and static electricity reducing sur'face onthe faces of the reed dents which engage the the conventional manner heretofore usedto assemble smoothefaced reed dents of the conventional type.
Some of the. objects .of theinvention having been stated, other objects will appear as the description proceeds, when taken in. connection with the accompanying drawings, in which- I V Figure 1 isa fragmentaryfront elevation of one end of a loom reedfra'me with the improved reed dents of the present invention supported therein; 7 t p Figure 2 is an elevation looking at the righthand end of Figure 1; i
Figure 3 is an enlarged side elevation of a fragment of the reed dent shown in Figure 2, encompassing substantially the area enclosed by the dotted rectangle in-p dicated at 3 in Figure 2; I
Figure 4 is a greatly enlarged horizontal sectional view through the reed dents shown. in Figure land being taken substantially along the line 4-4 in Figure 1;
Figure 5 is a view similar to Figure 4 exceptshowing a modified form of reed dents in which the friction and static electricity reducing finish is applied tov a debt which is oval in cross-section; and r Figure 6 is a greatly enlarged fragmentary view of the area encompassed by the dotted rectangle 6 in Figure 4and'illustrating the thread contacting the friction and static electricity reducing surface of a reed dent, which .in this instance has been plated.
friction and static electricity reducing, irregular surfaces 20. The irregular surfaces may be produced in a number of ways, in the present instance a matte finish has been obtained by a blasting process where loose abrasive material was blasted against the sides of the reed dent material by liquid and air pressure. This blasting process produces a smoothly pitted surface in which the amount of irregularity will vary in accordance with variations in the type of metal processed, the type of abrasive used and the pressure of the liquid and air.
"The irregular surfaces 20 may be plated with a thin layer of chrome or the like, indicated at 21 in Figure 6. The chrome plate layer 21 prevents corrosion of the metal and reduces wear of the reed dents 15 by the thread T as they engage the opposite sides'of the reed dents 15. As shown in Figure 6, the layer of chrome 21 is of uniform thickness and conforms to the irregular surface 29 of the reed dent 15. It is believed that frictiori is reduced because only the outwardly projecting portions of the surface 20 engage the surface of the thread T.
Referring to Figure 5, there is shown a modified form of reed dent, indicated broadly at 15' which comprises a body portion 19' that is oval in cross-section and has a roughened orirregular surface 20'.
reed dent'lS, shown-in Figure 4 and the oval reed dent The rectangular 15 :shown in Figure 5, are both conventional except for the -respective irregular surfaces 20 and 20 and it is to be understood that the irregular surfaces may also be applied to other conventional types of reed dents which have various cross-sectional configurations.
As heretofore stated, the present invention is of particula r value when Weaving threads of synthetic manmade fibers, however, matte finish reed dents may also indicated at 10 and comprises an upper reed back 11,
a lower reed'back 12 and end members 13, only one of which is shown. 'The ends of the upper and lower read be used to an advantage when weaving other types of thread. When weaving a continuous filament man-made thread, in addition to reducing the amount of friction and the static electricity builtup in the thread, the matte finish reed dents also add'protection against filament breakage and scuffing damage. Matte finish reed dents may. also be used to an advantage when weaving threads formed of staple length fibers, whether the fibers be natural or man-made fibers, and in addition to reducing the amount of friction and static electricity built up in the thread, themattefinish dents lessen the amount of fly accumulation, cause less distortion of the fibers in the threads, and provide better tension uniformity.
In practice, it hasbeen found that matte finish reed dents reduce friction thirty to fifty percent and substantially reduce the amount'of static electricity built up in the threads. Heretofore, it has been almost impossible to weave Dacron continuous filament threads because of the large amount of static electricity built up in the threads and it has been found that this type of thread may be woven satisfactorily by using matte finish'reed dents.
It has also been found that when. conventional smooth engaged by the reed dents of, thereciprocating reed.
However, when matte finish reed dents are used the coeificient of friction increases only slightlyas the speed of the reed increases. Thus, it is possible with the use Patented Mar. 14, 1961 V I U of matte finish reed dents to operate the weaving loom at a faster than normal rate of speed while maintaining I proved reed dents when viewed with the naked eye. The
surface of conventional reed dents is macroscopically smooth, shiny and specular while the surface of the present improved reed dent is macroscopically rough and non-specular and presents a dull gray-like metallic appearance to the eye.
However, a properly prepared matte-finish for the reed dents should be semi-dull in appearance and smooth to the touch. Actually'a fiat dull finish is undesirable. The desired finish may best be described by referenceto a standard gauge for measuring surface roughness by the heights of the irregularities with respect to an average line with the heights being expressed normally in micro-inches. In most instances the root-mean-square (R.M.S.) value is used which value is equal to the square root of the sum of the the deviation of individual points above or below the average line divided by the number of points measured. The standard gauge employed for measuring surface roughness is a Profilometer in which a sharp diamond stylus is moved at a constant rate across the surface to be measured and the rise and fall of the stylus are amplified electrically and indicated on a meter which is arranged to indicate directly the R.M.S. value of the surface. This apparatus is manufactured by Micrometrical Manufacturing Company of Ann Arbor, Michigan.
It has been determined that when the coeflicient of friction is plotted as an ordinate against surface roughness in micro-inches as theabscissa, for nylon particularly, the polished or shiny chrome surface range is indicated between and 20 R.M.S., and the matte finishes will range from 20 to 200 R.M.S. The preferred range for the macroscopically rough and non-specular matte surface will lie between 70 and 200 R.M.S. depending on the denier or other properties of the thread to be woven.
By providing the reed dents with a matte finish, the amount of friction between the threads guided by the dents and the amount of static' electricity built up in the threads are greatly reduced and additionally the threads are less likely to be damaged. It is preferred that the reed dents be finished with the matte surface before they are assembled in the reed frame and this blasting process in an economical manner.
In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.
1. An improved reed for a loom having a plurality of spaced apart metal dents between which warp threads are adapted to pass, the improvement comprising each dent having a macroscopically rough metallic surface provided with a non-specular, smoothly abraded, matte finish.
2. An improved reed for a loom having a plurality of spaced apart metal dents between which warp threads are adapted to pass, the improvement comprising a chrome coating on each dent with the surface of said coating being macroscopically rough, and said surface of said coating having a non-specular, smoothly pitted, matte finish.
3. An improved reed for a loom having a plurality of spaced apart metal dents between which warp threads are adapted to pass, the improvement comprising each dent having a macroscopically rough surface provided with a non-specular, smoothly pitted, matte finish, and a chrome coating on each dent having its outer surface conforming to the underlying surface of the dent.
References Cited in the file of this patent UNITED STATES PATENTS 1,070,206 Terryberry Aug. 12, 1913 1,420,262 Hurtr June 20, 1922 2,434,114 Lussardi Jan. 6, 1948 2,596,651 Carter May 13, 1952 2,705,977 Matthews Apr. 12, 1955 OTHER REFERENCES Walker Superior Reeds Advertisement, from Textile World, May 1951, page 157. Copy in class 139, subclass 192.