Show DUFF BALL BEARING SCREW JACKS communicated one of the most popular and efficient lines of jacks manufactured by the duff manufacturing company and sold through fairbanks morse company chicago is the duff ball bearing jack which is made in all types and sizes and which covers all sizes used in car shops round houses and for the safe and convenient handling of railroad equipment generally the duff ball bearing screw jack contains an improved ball bearing over any other jack of this character in that the balls are much larger in size therefore much stronger and capable of greater strains as well as operating much more easily under a load special tool steel plates are provided to take care of these balls in the main bearing so that practically a ly no wear whatever occurs during the constant operation of the jack in the most severe service ce another point which is an improved feature is the fact that the duff ball bearing jack contains an additional bearing on the bevel pinion to take the thrust at that point the duff jack is the only ball bearing jack containing a bearing at this point as all other jacks of this character are made with plain surfaces rubbing together causing considerable friction and rendering the jack much harder in operation in both bearings in the duff jacks the balls are separated by a bronze cage eliminating all friction between the balls this form of bearing is the most durable most substantial and most economical and from the standpoint of wearing qualities and ease of operation the duff ball bearing screw jack is a decided improvement over anything in this line that has been developed heretofore the duff manufacturing company also make a cone bearing journal jjack jack used by car inspectors which are made in ca pa opacities cIties of ten and fifteen tons and extremely popular for that work the regular duff ball bearing jacks range in capacities from ten tons to seven ty five tons and are made in various and with and without foot lifts special sizes are provided for the handling of railroad equipment and for shop work all gears in the duff ball bearing jacks are very high carbon steel stee drop forged and all have machine cut teeth the duff ball bearing jacks have been on the market for a number of years but this line has since been enlarged considerably and at the present time these jacks are operated on oil almost all of the leading railroads in the country with gratifying results special bulletins covering the duff ball bearing jacks are issued by the duff manufacturing fac turing company also fairbanks morse company fairbanks morse companas Comp anys line of lifting jacks at the present time includes the well known barrett track jacks the duff bethlehem forged steel hydraulic jacks and many other types outside of the duff ball bearing screw jacks above referred to and represents the largest and most complete line of jacks manufactured in the world |