A portable boring-welding machine with simplified drive

Abstract: A portable boring - welding machine, in which the rotation of the tool shaft or the torch shaft and, respectively, the axial movement of the tool shaft or torch shaft in both directions are driven by a combination of only two independent motors, which can be activated from the machine control unit. The motors are housed in a box which is integral with the machine structure and has a machine carryhandle. At least the motor which drives the rotation of the tool and torch shafts is of the direct current type and is subject to the action of means which adjust its speed and operating stroke, said means being positioned, respectively, on the control unit control panel and at end of stroke means, intercepted by actuators which follow the axial movement of the tool and torch shafts.

Description: The present invention relates to a portable boring - welding machine of the type comprising the features expressed within the preamble of claim 1 (see, for example, US-A-4 550 235). Machines of this type are already known on the market. The Applicant has, for many years, manufactured and sold a boring machine, marketed with the "bimotor plus" trade-mark, in which the tool axle/shaft and the torch axle/shaft are driven by two different motors or drive units, specifically dedicated to driving one (at high speed) and the other (at low speed). The two motors, or drive units, are connected, with different timing, to a unit which transmits the motion to the shafts. Said unit is supported inside the self-supporting machine structure. A third motor, or drive unit, is envisaged for obtaining an axial movement of the tool and torch axles/shafts. In the known machines, the three drive units, as described above, are housed in a box-shaped part of the machine, connected to the self-supporting structure. This box is shaped in such a way that it has, or may be fitted with, a handle for manual transportation of the machine. The use of three motors and the relative transmissions means that the dimensions of the above-mentioned box are significant and the machine heavy. Since it must be transported manually, it should, instead, be functional and at the same time very light. According to the documents US 4550235 and EP 0537124 are also known boring - welding machines used to restore the original dimensions of holes or seats on machines or machine parts having an axle/shaft adapted to hold at least a boring tool. The axle/shaft is driven, in rotation and in an axial movement by two independent drive units which can be housed within a box having a handle for manually transporting the machine. The aim of the present invention is to provide a boring machine of the above-mentioned type, in which the rotation of the tool or torch shafts and, respectively, the axial movement in either direction, of said shafts, are powered by only two independent motors, in combination. The two motors can be activated from the machine control unit and are both housed in the same machine box with a carry-handle. At least the motor designed to rotate the tool and torch shafts is a direct current motor and is subject to the action of means which adjust its speed and stroke, respectively positioned on the control panel of the control unit and at end of stroke means which can be intercepted by actuators which follow the axial movement of the tool and torch shafts. Experiments have indicated that this motor combination provides optimum adjustment of the speed of the tool and torch axles/shafts, with a small reduction in the number of transmission means until now necessary for the above-mentioned drive and, advantageously, a reduction in the overall weight of the machine. In addition, machine assembly is facilitated and the machine is, overall, economical to make, thanks to its simplified operating shaft drive system. The technical features of the present invention are more clearly described in the detailed description of the machine below, with reference to the accompanying drawings, which illustrate an embodiment of the invention, without limiting the scope of its application, and in which: Figure 1 is a perspective rear view of the machine according to the present invention, without the drive means box cover; Figure 2 is a perspective front side view of the machine disclosed, temporarily mounted on a support and in the same conditions as illustrated in Figure 1; Figure 3 is another front side view of the machine disclosed, in the same conditions as in Figure 2. The machine disclosed is of the type comprising a structure 1 which houses support parts such as bushings, bearings, etc. which allow the rotation (and simultaneous forward/backward movement) of a shaft (not illustrated in the accompanying drawings) which longitudinally passes through the entire body of the machine, exiting at least from the front of the machine, by a length sufficient to bring one or more boring tools, or a welding torch, to the operating position. The rotation and forward/backward movement of the shaft allow said boring tools and welding torch to operate inside holes (through-holes and blind holes) in a part to be machined and to which the machine can be fixed. The boring machine disclosed can be used for boring operations and, respectively, to apply material, in order to restore the original conditions of the seats (through- or blind holes) worn by use. The holes or seats normally house and support knuckle pins or axles of machine tool elements, for example, earth-moving machinery, or pins or axles of machines or equipment subject to significant stresses which, over time, make the support seats oval, creating unwanted play which must be eliminated. If boring operations must be carried out, the shaft which runs longitudinally through the entire body of the machine has at least one longitudinal groove for torsional attachment of the shaft to the means on the machine which drive its rotation. Said means, in the boring machine disclosed, are housed in the front part of the machine and, in accordance with the present invention, are driven by a first drive unit 2, to which they are kinematically connected by a toothed belt 3 which is partially wound around a toothed pulley 4 keyed to the axle of the drive unit 2, and partially wound around the toothed sleeve of a bushing 5 (illustrated in Figure 3) inside which the above-mentioned shaft translates thanks to its torsional engagement with the bushing, thus being rotated by the latter. At regular intervals along its length and at least on the part projecting from the front of the machine, the shaft has seats which can house and support the shank of boring tools, which can be positioned in them and adjusted so that they project radially from the shaft, using known techniques which are not, therefore, described. If material must be applied in the seat, the shaft which runs longitudinally through the entire body of the machine again has at least one longitudinal groove for torsional attachment of the shaft to the means on the machine which drive its rotation, said means being those driven by the drive unit 2. In this case, there is a longitudinal through-hole in the shaft, through which one or more cables and/or power leads of a welding torch can be passed, said torch being fixed to the front of the shaft. In both cases, the shaft which passes through the entire body of the machine can be moved axially by means of a joint 6 at the rear of the machine. The joint 6 comprises a pair of jaws 6a - 6b, which move towards and/or away from one another, and which can be clamped together about the outer sleeve of the tool shaft or torch shaft. The jaws 6a - 6b are supported by a bushing 7, mounted on a tubular bar, the outside of which is threaded, which in turn engages with another bushing 8, the inside of which is threaded, supported by the machine body at the rear (illustrated in Figure 1). The bushing 8 is kinematically connected, by a toothed belt 9, to the second machine drive unit 10 (see Figure 1) so that the rotation of the bushing 8 corresponds with an axial movement of the threaded bar and, as a result, of the bushing 7 to which the jaws 6a - 6b are connected. The bushing 7 is connected to the threaded bar by bearings (not visible in the accompanying drawings), which allow it to rotate relative to the bar without the possibility of a relative axial movement. As a result, with the jaws 6a - 6b clamped on the tool shaft or the torch shaft, the bushing 7 can rotate with the shafts rotated by the first drive unit 2, there remaining the possibility that the threaded bar may be moved forward/backward axially to the machine by the second drive unit 10, moving said tool shaft and/or torch shaft forward/backward. At least the first drive unit 2 is of the direct current type and allows optimum adjustment of the speed of rotation of the tool shaft and, respectively, the torch shaft, without requiring special reduction gear units, as occurs in the prior art. As is clearly illustrated in the accompanying drawings, the two drive units 2 and 10 are housed in a box-shaped part 1A of the machine. This part 1A is designed so that it is closed with a cover (not illustrated in the accompanying drawings) fitted with a machine carry-handle. In the same area in which the cover is positioned, as is known, the machine also has one or more support rods for the machine electrical control unit. The electrical circuits and relative potentiometers, relays, switches, etc. for the control of the two drive units 2 and 10 are connected to the control unit. One side of the machine (see Figure 1) may be fitted with end of stroke devices 11, with adjustable position, which can be intercepted by actuators able to follow the axial translation of the tool or torch shafts and inserted in the electrical control circuit of at least the drive unit 10 and able to stop said drive unit when the shafts have completed their working stoke.

Claims: A portable boring - welding machine, of the type used to restore the original dimensions of holes or seats for knuckle pins, rotation bushing, etc., on machines or machine parts to which the boring welding machine can be temporarily fixed, without having to transport the part to be machined to the workshop and without positioning the part on machine tools, the portable boring - welding machine comprising : a structure; an axle/shaft engaged to the structure to hold one of an associated boring or a welding tool, the axle/shaft being movable to rotate and to axial move relative to the structure; only two independent drive units (2, 10) operatively connected to the axle/shaft, the first drive unit (2) being adapted to rotate the axle/shaft, the second drive unit (10) being adapted to axial move the axle/shaft in its both axially directions, the independent drive units (2, 10) being activated by a machine control unit and being housed within a box positioned on the structure, the first drive unit which drives the rotation of the axle/shaft being a direct current drive unit; rotation means housed in the front part of the machine, being kinematically connected to the first drive unit (2) by a tooth belt (3) which is partially wound over a toothed pulley (4), the latter being keyed to the axle of the drive unit (2), and partially wound around the toothed sleeve of a bushing (5), the shaft translating inside said bushing (5) being torsionally engaged with the bushing (5) and, therefore, rotate by it; a handle connected to the structure for manually transporting the machine engaged to the box, characterized in that the machine also comprises a joint (6) mounted at the rear of the machine, the joint comprising a pair of jaws (6a, 6b) which can be clamped together on the axle/shaft, said jaws (6a, 6b) being supported by a bushing (7) mounted on a tubular bar, the exterior of said bar being threaded and engaging with another bushing (8), the latter having a threaded interior and being supported by the rear part of the machine body, the other bushing (8) being kinematically connected, by a toothed belt (9), to the second drive unit (10) in such a way that the rotation of the other bushing (8) corresponds with an axial translation of the threaded bar and, as a result, of the bushing (7) to which the jaws (6a, 6b) are connected. The portable boring - welding machine according to claim 1, characterised in that the electrical power supply circuit of the direct current drive unit (2) is fitted with means which adjust its speed and operating stroke, being positioned respectively on the control unit control panel and at end of stroke means with adjustable positioning, the latter being intercepted by actuator means which can follow the axial movement of the tool and torch shafts. The boring machine according to claim 1, characterised in that the bushing (7) is connected to the threaded bar by means of bearings, leaving it free to rotate relative to the bar without the possibility of any relative axial movements.

Inventors: SIRACUSA RINALDO, SIRACUSA, RINALDO
Applicants: SIR MECCANICA S R L, SIR MECCANICA S.R.L.
Application year: 1999
Main classification: B23K7
IPC codes: B23K7