Abstract: A high temperature bolting system for clamping steam turbine housings and similar high temperature parts together while operating at a temperature of 800° F. to 1200° F. An elongated fastener shank and housing material have similar coefficient of thermal expansion. The shank has a tensile strength several times greater than the housing to maintain a clamping force during thermal excursions. The diameter of the shank is reduced due to the large creep strength difference between the elongated fastener shank and the clamped parts. The reduced shank diameter allows an increased in the clamping load by providing an increased surface area in the clamped part. A stress generating flange is provided with jackbolts to establish the clamping load at room temperature. A threaded sleeve is interposed between the threads at the end of the shank and the threads of the housing so that the housing threads have a sufficiently large area for withstanding the clamping load.

Abstract: Jackbolts for multi jackbolt tensioner embody a thread construction which taper from a maximum diameter adjacent to torque receiving end of the jackbolt when threadedly engaged with a threaded opening in the outer peripheral part of a jackbolt body. The threads of the jackbolt have a different thread pitch than the threads in the jackbolt body and the tooth flank of the jackbolt threads for an angle with the tooth flanks of the thread in the jackbolt body. By this thread construction, there is formed a helical volume of ever increasing size along the jackbolts commencing at a metal to metal relation at the torque receiving end. Stressing of the jackbolt closes the helical volume bringing the threads to a metal to metal load transfer relation. The end of the jackbolts has a protruding central end portion that elastically flattens under stress to reduce torque requirements.

Abstract: A high temperature bolting system for clamping steam turbine housings and similar high temperature parts together while operating at a temperature of 800° F. to 1200° F. An elongated fastener shank and housing material have similar coefficient of thermal expansion. The shank has a tensile strength several times greater than the housing to maintain a clamping force during thermal excursions. The diameter of the shank is reduced due to the large creep strength difference between the elongated fastener shank and the clamped parts. The reduced shank diameter allows an increased in the clamping load by providing an increased surface area in the clamped part. A stress generating flange is provided with jackbolts to establish the clamping load at room temperature. A threaded sleeve is interposed between the threads at the end of the shank and the threads of the housing so that the housing threads have a sufficiently large area for withstanding the clamping load.

Abstract: Jackbolts for multi jackbolt tensioner embody a thread construction which taper from a maximum diameter adjacent to torque receiving end of the jackbolt when threadedly engaged with a threaded opening in the outer peripheral part of a jackbolt body. The threads of the jackbolt have a different thread pitch than the threads in the jackbolt body and the tooth flank of the jackbolt threads for an angle with the tooth flanks of the thread in the jackbolt body. By this thread construction, there is formed a helical volume of ever increasing size along the jackbolts commencing at a metal to metal relation at the torque receiving end. Stressing of the jackbolt closes the helical volume bringing the threads to a metal to metal load transfer relation. The end of the jackbolts has a protruding central end portion that elastically flattens under stress to reduce torque requirements.

Abstract: An apparatus including a plurality of jack bolts which are threadedly engaged with openings in a flange on a fastener to stress a shank part of the fastener. The flange can be a collar retained on a shaft by a retainer, a nut on a threaded end of a bolt, or the head portion of a bolt. The jack bolts can be arranged in a flange on an end of a tension rod to stress arbors against opposite sides of a roll sleeve to form a roll assembly for use in a rolling mill. The apparatus includes structure for preventing escape of the jack bolts from the flange which is particularly advantageous when the apparatus is secured to moving machinery where the presence of escaped jack bolts could cause damage to the machinery.

Abstract: A multiple jack bolt assembly, wherein a tensioner body component of the assembly, which may take the form of a nut, bolt, thrust collar, and the like, is provided in addition to its plurality of standard jack bolt holes with at least one additional drilled and tapped release hole for receiving a corresponding plurality of release jack bolts. The additional jack bolt hole or holes preferably remain empty during installation and the load cycle of the jack bolt system and it is also preferred that they and the release jack bolts received therein vary in construction from the standard jack bolt holes and jack bolts. When it is desired to remove the multiple jack bolt tensioning device, the release jack bolt holes are first cleaned (if necessary) and lubricated.

Abstract: A fastener for use where a predetermined holding force of holding position is to be maintained while the fastener is required to exert a holding force less than the full maximum force it is capable of exerting, the fastener having a shaft portion that threadedly fits into a nut, the shaft portion having an angular cut forming a spring like member, with an outer projecting portion biased toward a surface of the nut for causing a resistance to rotation of the fastener relative to the nut, and wherein the nut may take the form of a thrust collar that receives a number of the fasteners for maintaining a bearing on a journal.

Abstract: A plurality of jack bolts are threadedly engaged with openings in a flange on a fastener to stress a shank part of the fastener. The flange can be a collar retained on a shaft by a retainer, a nut on a threaded end of a bolt or the head portion of a bolt. The jack bolts can be arranged in a flange on an end of the tension rod to stress arbors against opposite sides of a roll sleeve to form a roll assembly for use in a rolling mill.