[Footnote: From a paper read before the "Technischen Verein" of New York, May 28, 1887.]
By CHAS. A. SCHIEREN.
The old saying that "there is nothing new under the sun" may well be applied to leather link belting. It is generally believed that these belts are of recent invention, but that is an error. They are over thirty years old.
Mr. C.M. Roullier, of Paris, experimented that long ago with small leather links one and one-half inches long by three-quarters of an inch wide. These links had two small holes at equal distances apart, and were joined with iron bolts, which were riveted at the ends, thus making a perfectly flat surface, and in that way forming a belt entirely of leather links.
Mr. Roullier's idea was to economize; he therefore utilized the material left over from the manufacture of flat belting. He perfected his belt and came to this country in 1862, when he patented the article here and tried to introduce it. At first it produced quite a sensation, and many tests were made, but it was soon found that Roullier's belts were not suited to running our swift motion machinery, and they were therefore abandoned as impracticable.
Mr. Roullier then introduced his invention into England, where he met with some success, as his belt was better suited to English slow motion machinery.
These belts are now largely used in England, many good improvements have been made in them, and almost every belt maker in Great Britain manufactures them.
Mr. Jabez Oldfield, of Glasgow, has the reputation of making the best and most reliable link belt in Great Britain. He has also the reputation of being the originator of these belts. This is, however, an error, the credit of the invention belonging, as we have said, to Mr. Roullier.
Mr. Oldfield, nevertheless, has invented many useful machines for cutting and assorting the links. He has also introduced improved methods for putting the links together.
For more than twenty years after Mr. Roullier's visit, nothing was done with leather link belting in this country.
In 1882, however, Mr. N.W. Hall, of Newark, N.J., patented a link belt, composed of leather and steel links. His method was to place a steel link after every third or fourth leather one, in order to strengthen the belt. In practical use this belt was found to be very defective, because the leather links soon stretched, and thus all the work had to be done by the steel links. The whole strain coming thus upon the steel links, they in course of time cut through the bolts and thus broke the belt to pieces. So this invention proved worthless.
In 1884 a Chicago belt company obtained a patent on another style of link belt. In this belt all the little holes in the links were lined with metal, similar to the holes in laced shoes. This produced an effect similar to that produced by Hall's patent. The metal lining of the holes cut the bolts into pieces by friction and thus ruined the belt. Therefore this patent proved a failure also.
After all these failures it fell to our lot to improve these belts so that they may now be worked successfully on our American fast running machinery. During the past two years we have made and sold over five hundred leather link belts, which are all in actual use and doing excellent service, as is proved by many testimonials which we have received.
Our success with these belts has been so surprising that we think we have found, at last, the long looked for "missing link," not in "Darwinism," however, but in the belting line. We prophesy a great future for these belts in this country.
How have we attained such success? First: We found that Roullier made a mistake in using leather offal, as, in the links of an iron chain, if one link is weak or defective, the whole chain is worthless, so in link belts, if one or two links are weak or made of poor material, the whole belt is affected by them. It is therefore of vital importance that only the best and most solid leather be used in making the links; second, the leather must be made very pliable, but at the same time its toughness and tenacity must not be injured, or it will stretch and break.
These things are of great importance, and are the principal reasons for the failures of all former efforts. The leather which Roullier used was stiff, hard, and husky. He believed that the harder the link the greater its tensile strength, but upon actual test this was found to be a fatal error.
Our leather links are saturated with a mixture of tallow, neatsfoot oil, etc. This makes them very pliable and increases their toughness, so that they will stand a strain three times as great as a piece of hard rolled sole leather.
In manufacturing this belt, the joining together is important. The links must be accurately assorted as to thickness, and the outer links countersunk, to admit the bolt. Then the most valuable improvement of all is our "American joint" (see Fig. 1).
By close inspection you will observe that it is absolutely necessary to use half length bolts for the width of wide leather link belts.
Examine Figs. 2 and 3. In the latter you will notice one length of bolt placed on a round faced pulley. That belt must either bend or break, and in any case it will not give satisfaction; but, on the other hand, examine Fig. 2; here two half length bolts are used, and ingeniously joined in the center. It gives just pliability enough to lay the belt flat upon the pulley. We experimented for some time before perfecting this important improvement.
We also took out four patents for different methods of joining, but abandoned them all and adopted the "American joint" system (Fig. 1) as the most efficient, simple, and reliable. It gives the belt an unbroken flat surface and is far superior to anything so far introduced for that purpose.
We have not stopped at flat link belting, but have turned our attention to manufacturing round solid leather link belting, and believe that we have almost attained perfection in that line. As the illustrations clearly show, there is quite a demand for inch and upward solid round belting, and the difficulty always has been to join such a belt together. All steel hooks, etc., do not seem to satisfy. This, our new invention, is so simple that it hardly needs explanation. A belt of this kind can be taken apart in a short time, and shortened or lengthened at pleasure.
Now, Mr. President and gentlemen, I shall be glad to answer any questions in reference to these link belts, or give any further explanation you may desire.
Can these link belts be used on dynamos for electric lights?
Yes. In England they are used almost exclusively on dynamos. However, they run only 700 revolutions per minute there, whereas our slowest dynamo runs 1,100.
Would you advise link belts for high rate of speed?
No; they give better results on slow running machinery.
Have these belts any special advantage over flat leather belting?
Yes, decidedly. When belts are run half crossed, or what is termed quarter turn, it is very hard to make flat belts lie perfectly even on the pulleys. These link belts, however, cover the entire face of the pulley (see illustration), and therefore are superior for that purpose.
Why do they give better results when run slow?
Partly because of their great weight over ordinary belting, also their grip power is stronger when run slow. No belt is superior to them for slow, hard working machinery.
Are they more expensive than ordinary flat belting?
Not when compared to the work they can accomplish.
Can they be run in wet places, such as mines, etc.?
Yes; by waterproofing the leather, no cement being used as in flat belts. The links can be made positively waterproof. We have furnished paper mills, tanneries and bleacheries, and other exposed places with waterproof link belts, and all have been entirely satisfactory so far.
Can they be run on ordinary flat pulleys?
Yes; our "American joint" link belt can be run on any straight or rounded pulley, whether made of iron, paper, or wood, and being all endless they run much smoother than other belting.
ENGLISH HINGE JOINT:
How are they made endless?
By a very simple process (see illustration), and takes almost less time than lacing a flat belt. All that is necessary is to take both ends and interlock the links, then pass the bolt through and rivet it, and when you wish to shorten the belt proceed likewise: File off the end of the bolt and take out, or add rows of links at pleasure and rejoin it again.
Fig. 4 is a complete round link belt.
What is the relative strength of a link belt compared to flat belting?
Nothing definite has yet been ascertained. We are preparing a table showing results, and so far we can report that they can stand about twice the strain of double flat belts. A four inch link belt one inch thick is able to do the work of an eight inch flat double belt.
Fig. 5 is a side view.
Explain the advantage of your American joint over the English hinge.
The American joint gives a perfect unbroken surface of entire width of belt, whereas the English hinge joint makes two half widths, and whenever a sudden change of power occurs and the belt runs half way off the pulley, it will catch at the edge and tear everything to pieces.
Fig. 6 is an end view.
Have you a table or schedule of their weight per square foot?
Yes. The following is as near as we can estimate the weight of leather link belting per square foot:
1 inch thick, about 5 lb. per sq. ft. 7/8 " " " 4½ " " " 3/4 " " " 4 " " " 5/8 " " " 3½ " " "
Upon motion a vote of thanks was passed, and the paper read ordered to be printed.
Fig. 7 is a single link.