362 



THE INDIA RUBBER WORLD 



[March 1, 1920. 



New Machines and Appliances. 



MACHINE FOR CALCULATING FABRIC WASTE IN FOOTWEAR 

 MANUFACTURE. 



FIGURING waste percentages on fabric cutting in tlie rubber 

 shoe industry is a problem which has increased mi iirpor- 

 tance with the rise in price of all kinds of cloth. The 

 method most widely used is to weigh the waste and compute 

 the percentage by either weighing the table of stock before cut- 

 ting or the cut stock after each performance. The machine here 

 shown has solved this problem for both the leather shoe and 

 the canvas shoe manufacturer. The method involved diflfers in 

 that it figures in terms of square feet instead of pounds. 



To install the service, the manufacturer first sends a model 

 sire of each pattern or die. such as men's quarter, size 8. boys' 



The Krippendorf K.alcul.\tor. 



lining, size 5, misses cloth heel, si/c 13-2, to the laboratory of 

 the machine company for survey. The result of this survey is a 

 pattern value or inde.K which, when computed on the Kalculator, 

 will tell e.xactly the number of square feet of stock needed to 

 cut out the required number of pairs at the best percentage of 

 waste. 



To operate the machine, ihe pattern value for the model size is 

 set on the indicator. Supposing the ticket to be cut is 36 pairs : 

 3 pairs, size 6; 4 pairs, size SVi ; 5 pairs, size 5; 6 pairs, size 4J4 ; 

 5 pairs, size 4; 6 pairs, size 35^ : 4 pairs, size 3; 3 pairs, size 2J^. 

 These sizes and pairs are recorded on the cylindrical dial, the 

 width is set on the scale near the base of the machine, and the 

 answer is found in the center— 5^4 square feet. This gives the 

 cutter an accurate goal. He knows that this is the best possible 

 performance. 



In cutting leather the general • policy is to grade down from 

 the best possible, giving a scale of 8 or 9 performances, leaving 

 it to the manufacturer to decide at which performance he will 

 ■begin to pay bonus. Leather is so irregular in shape and the 

 <iuality of different parts of the hides is so varied, that this wide 

 latitude is necessary. 



In cutting rubber or canvas duck a scale of 3 or 4 perform- 

 ances is suflicient. The tables of stock are generally uniform 

 in width and length. This makes it desirable to transpose the 

 square feet answer into running feet. Thus, if it requires 51 

 square feet of stock to cut 36 pairs of vamps, and the tables of 

 stock are 15 feet long and 3 feet wide, it will take 17 running 

 ieet of stock or one table and a fraction. The fact that the 

 stocks are laid from 20 to -^0 plies in thickness does not com- 

 plicate matters. The number of pairs in each cut can be easily 

 computed. 



There are several .ulvaniagi-s of this system over the present 

 methods used in rubber shoe cutting rooms. It eliminates the 



weighing of waste, stock, and cut stock, all of which takes time 

 and therefore costs money. The only additional equipment it 

 requires is the making of each cutter's table iiUo a scale of feet. 

 A cost clerk can thus very easily complete the cutting record 

 after each performance without moving the stock from the cut- 

 ters' table. The cost accountant has a reliable figure as to how 

 much stock it takes, including the waste which must go into the 

 cost of the shoe, to cut a pair of every pattern used in all goods 

 from light gum shoes to boots and heavy gaiters. The cutter 

 who has difficult patterns which do not fit or dovetail together 

 well, knows the limits of his patterns, and is not penalized be- 

 cause his percentages are not as low as the cutter who cuts 

 insoles or some oblong shape patterns. The machine is double, 

 thus enabling two patterns to be figured together such as toe 

 tips and fillers. 



.\nother advantage of the Kalculator is that it enables the 

 planning department to figure e.xactly how many running feet 

 of stock the mill room needs to run for each day's ticket. This 

 avoids surplus rolls in the stock room and means less money 

 tied up in unfinished material. (Krippendorf Kalculator Co., 

 Lynn, Massachusetts.) 



SAFETY MOTOR STARTERS. 



-\s a safety measure, motor starters should be completely en- 

 closed to protect workmen from coming in contact with live 

 parts. The two safety starters of the enclosed type here shown 

 are therefore of interest. 



The first is the familiar type of direct-current face-plate starter 

 enclosed in a sheet metal case having an external lever which 

 engages the movable arm of the starter. The external or op- 

 t>rating lever is insulated from the revolving contact arm by a 

 block of molded insulation. A pointer on the lever and legends 

 stamped on the cover indicate whether the starter is "off" or 

 "on." In the smallest size of starter a knob of black insulating 

 composition is provided in place of the operating lever. A 

 low-voltage release coil in series with the shunt field protects 

 the motor in case of voltage failure or if the field should be 

 opened while the motor is running. The armature resistor is 

 completely enclosed in the starter case, which is kept well ven- 

 tilated by a flue in the top. 



This starter is used with direct-current motors up to 50 h.-p., 

 operating at 115. 230 and 500 volts. 



Open. Closed. 



Face Plate Enclosed Motor Starter. 



The second is an automatic motor starter panel of the counler- 

 E. M. F. type completely enclosed in a cast iron case with a 

 hinged cover. The automatic feature is obtained by an accelerat- 

 ing contactor which closes when the motor attains about three- 

 fourths full speed, and automatically shunts out the starting 

 resistor. A magnetic main line contactor mounted on the panel 

 allows remote control from two push-button switches of the 

 momentary contact type. 



When remote control is not desired the magnetic main line 



