Patent GB-612368-A (GB)
Title: Improvements in or relating to apparatus for installing a tubular rivet
IPC: B25B27/00
Filed: 1946-05-21
Abstract: 612,368. Riveting. GOODRICH CO., B. F. May 21, 1946. No. 15408. Convention date, May 22, 1945. [Class 43] Apparatus for installing a tubular internally-threaded rivet comprises a hollow anvil through which extends a rod having a threaded end for engaging the threaded part of the rivet, means for rotating the rod to engage it in or disengage it from the rivet, a housing supporting said rod and anvil, and power-operated, hydraulic means enclosed by the housing for providing relative axial movement of the rod and anvil to upset the rivet, Means for rotating said rod, and means for developing said hydraulic pressure may be mounted on or in the body and may be operable by hand or by power. In the form shown in Fig. 3, a rod 12 is rotatable in a body 10 in order to effect internal screw-thread engagement of its end 13 with the rivet 14. A tubular anvil 49, rested against the head of the rivet, slidably surrounds one end of the rod 12 and is fixed adjustably to a piston 47 which, with its extension 48, is slidable on a tubular bearing 46 in the cylinder 45, in which bearing the other end of the rod 12 is slidable. By transferring liquid under pressure gradually from one side of the piston 47 to the other, the body 10 is displaced gradually away from the anvil 49 resting on the rivet, and so draws the rod slightly through the anvil to upset the rivet. The rod 12 is caused to engage in or disengage from the rivet by pushing in or pulling out from a handle 36, secured to the body by a collar 28, a knobbed tubular plunger 39 having a high-pitch internal screw thread 40 engaging an external thread 25 on a rod 21 slidable and rotatable within the plunger, and secured to the rod 12 by a coupling block 16, restrained from movement axially by the rod. For effecting the relative movement between the rod 12 and anvil 49 to upset the rivet, a lever 88 pivoted at 89 to an arm 90 fixed on the body 10 is reciprocated by hand. and through a link 86 causes reciprocation of a pump plunger 82 in a cylinder 75 containing e.g. oil or glycerine. At each inward stroke of this plunger the pressure produced in the liquid first closes a ball valve 106, and then causes the liquid to pass through the duct 95, ball valve 109, and duct 97 to the left side of the piston 47, where the effect of its pressure is to cause the cylinder 45, and therefore the whole body 10, to move to the left relatively to the piston, which remains at rest by reason' of its fixed connection with the anvil 49 resting against the stationary workpiece. At each outward stroke of the plunger 82, the valve 106 reopens and liquid is drawn from the right of the piston 47 through ducts 101, 100, 99 and 98 and the valve 106 into the cylinder 75. These movements are repeated until the piston is arrested by a stop 64 or by the engagement of a pre-set collar 134 on the extension 48 of the piston rod with a lever 132 pivoted at 133 to the body 10 and adapted with its end 133 to displace in a cavity 100 a plunger 120, sealed to the cavity by a resilient jacket 118, and so unseat a ball-valve 127, thereby opening up a passage between the two sides of the piston 47 via ducts 97, 96, opening 125a, cavity 100 and duct 101. Manual pressure applied to a knob 140 on the punger maintains this passage open until the piston return spring 65 has returned the piston 47 to the extreme left of its cylinder. A seal 141 similar to the jacket 118 is provided to close the righthand end of the cylinder where the piston extenson 48 emerges. The cylinder 45 has a screw-plugged opening 146 and a bleeder vent 170 for letting out entrapped air. In a modification (Figs. 5 and 6, not shown) power operation replaces hand operation. The body 10 and its contents remain unchanged, but the handle 36 and lever system 88, 86 are replaced by a pistol handle which is secured to the body and is provided with ducts connectible to a source of air pressure, and supplying air to (1) a reversible air motor in the handle, having its shaft in alignment with the rod 12 and coupled thereto through planetary reduction gearing and the coupling block 16, and (2) a hollow valve rod slidable in a chamber parallel to a cylinder housing a piston having its rod in alignment with the pump plunger 82, operation of one or other of a pair of levers on the pistol handle serves to actuate the air motor in order to cause the rod 12 to engage or disengage the rivet. Operation of a trigger on said handle admits air to displace the valve rod and cause air to pass therethrough to one side of the piston operating the pump plunger 82, at the same time opening the other side of said piston to the atmosphere. The piston and plunger 82 are thus displaced in one direction until an adjustable arm on the moving piston rod returns the valve rod and so reverses the compressed air and atmosphere connections to the two sides of the cylinder, causing the piston and plunger to return to their starting point to begin a further reciprocation, and so on as long as the trigger is held depressed. In a !further modification (Fig. 7, not shown) the movement of the rod 12 with respect to the rivet and also with respect to the anvil are effected from a motor shaft through gearing contained in a housing secured to the side of the body 10 in replacement of the manual controls. The motor shaft has two spaced sets of gear teeth driving pinions riding loosely on a parallel shaft secured by the coupling 16 to the rod 13. A slidable cone friction clutch between said pinions in one extreme position couples one pinion directly to the parallel shaft, and in the other extreme position couples the other pinion to said shaft through a reversing gear train, thereby providing for the rotation of the rod 12 in either sense. With the cone clutch in neutral position, rotation is transmitted from the motor shaft through the first-mentioned pinion to a pinion turning on a ballrace co-axial with the pump plunger 82. This pinion is coupled by a slidable cone friction clutch to a hollow shaft, mounted in alignment with the plunger 82 and having on its internal surface a continuous cam groove of sinecurve form engaging a roller rotatable on a pin fixed to the head of the plunger 82, thereby effecting reciprocation of this plunger so long as the two clutches remain so connected. Specification 459,973 is referred to.