Frapping tool
TECHNICAL FIELD:
The present invention relates to a procedure and a tool for binding together crosslaid trussing irons, for instance, tying with wire which is placed around and twisted at the point where the trussing irons cross each other. Tying also occurs during electrical work, for instance when cable coils and VP pipes are secured to cable racks, and also when tying wire is to be twisted.
BACKGROUND ART: Tying is physically strenuous work which has previously been performed in most cases using tying pliers, where a cut length of wire is placed around the objects to be tied and then the pliers are used to twist together the ends of the wire so that the objects are held together.
There is considerable risk of wear injuries, particularly to the back, with this method of tying.
There is also risk of injury due to the worker cutting himself on protruding tie joints since, with this method, it is preferable not to use gloves so as to maintain finger-tip sensitivity.
Another known tying method is to use pre-shaped tying wires with loops at both ends. These pre-shaped tying wires are placed around the objects to be tied and a twisting tool with a hook is hooked through both loops of the tying wires, after which rotation of the hook is effected by pulling the tool so that the tying wires are twisted. The risk of wear injuries, particularly to the back, is considerable with this known tying method as well. The pre-shaped tying wires also constitute a considerable increase in cost in comparison with wire obtainable by the metre.
A tying method is also known which uses a manually operated tying tool intended for upper edge reinforcing. According to this method the tie joint is achieved using specially manufactured metal clamps which are loaded into the tool in the form of a magazine. By pressing down two handles in the upper edge of the tool, the lowermost clamp in the magazine is caused to leave the tool and bend around the reinforcing intersection. The tie joint is then complete and the tool can be placed over the next intersection and the procedure repeated. The method requires a relatively complicated tying tool, resulting in lack of functionality. The tool is also relatively heavy, 8.6 kg and requires pre-shaped tying clamps to fit the thickness of the trussing iron and different types of tying clamps are therefore necessary for different diameters of iron, involving increased cost in comparison with wire obtainable by the metre. Only certain types of tying can be performed, due to the size of the tool.
Yet another method is to use a manually operated tool for tying and spacing through lower edge reinforcing. The tie joint is achieved using specially manufactured plastic cubes which are loaded into the tool in a magazine. By depressing two handles in the upper edge of the tool, the lowermost cube in the magazine is caused to leave the tool and is placed beneath the
reinforcing intersection. The tie joint is then complete. This tool is also relatively heavy, approximately 7 kg and the method cannot be used on VP pipes. Furthermore the magazine is able to hold far too few plastic cubes, which means that the magazine must be replaced relatively frequently. Each plastic cube is also relatively complicated and thus expensive. Furthermore, the tool can only be used for a limited number of work phases.
Specially manufactured, rechargeable electric tools are also available for tying, having a wire store in the form of a reel of wire with a capacity of 150 tying operations. These tools are expensive and relatively bulky. In size and weight they are equivalent to a conventional electric drill. These machines also require a special type of tying wire.
Pneumatically operated tying tools also exist, which are supplied manually with specially manufactured tying clamps. Drawbacks with these tools are the need for access to compressed air and the compressed-air hose therefore required.
Reinforcing robots exist which are used for fitting prefabricated reinforcement cages on concrete beams. These robots incur a high investment cost and are only suitable for mass- producing special reinforced components.
OBJECT OF THE INVENTION:
The object of the present invention is to provide a procedure and a tool for joining together trussing irons used in concreting and/or securing VP pipes for electric cables.
Another object of the invention is to provide a tying tool that eliminates the drawbacks exhibited by previous tying tools and offers beneficial qualities as regards function, performance, environmental endurance, personal safety, vibrations and weight.
The object is also to provide a tying tool which is economic to produce and in use.
BRIEF DESCRIPTION OF THE INVENTION:
The present invention constitutes a tying procedure in which at least one first cutting member, due to a translation movement achieved by a rotating shaft, is moved towards a second cutting member for cutting cooperation in a first stage of the translation movement. Thereafter, upon continued translation movement in the same direction, a first mating surface on the first cutting member is pressed against a second mating surface on the other cutting member in order to retain the wire parts situated between the surfaces, the wire parts then being twisted by accompanying the rotation of the shaft. The tying operation is complete when the wire parts have been twisted and the parts can then be detached by changing the direction of rotation of the shaft. The two mating surfaces are thus separated from each other and the wire parts are detached.
A first embodiment of the procedure utilizes a translation movement at right angles to the rotating shaft. In this case two first cutting members are pressed simultaneously against a corresponding second cutting member arranged on the shaft.
A second embodiment of the procedure utilizes a translation movement parallel with the rotating shaft. In this case a first axially movable, cylindrical cutting member is pressed against a corresponding second cylindrical cutting member arranged stationarily on the shaft.
The second embodiment is also shown as a complete tying tool.
BRIEF DESCRIPTION OF THE DRAWINGS:
The invention will now be described in more detail with reference to the accompanying drawings. Identical components in one figure of the drawings have the same designations in other figures.
Figure 1 shows a side view of a cutting and pressing tool illustrating a first procedure according to the invention. Figure 2 shows a view from above of the tool according to Figure 1. Figure 3 shows a section along the line A-A in Figure 2.
Figure 4 shows a view from above of a tying tool according to the present invention operating in accordance with an alternative procedure according to the invention. Figure 5 shows a side view of the tool according to Figure 4.
Figure 6 shows a section along the line B-B indicated in Figure 5 when the tool is open. Figure 7 shows the same section as in Figure 5 but when the tool is in closed, ready cut position. Figure 8 shows a section along the line C-C in Figure 5. Figure 9 shows a section along the line D-D in Figure 5.
DESCRIPTION OF THE INVENTION:
To begin with, an illustration of a first tying procedure according to the invention will be described. Figure 1 showing a cutting and pressing tool 1 comprising a first tool part 2 and a second tool part 3. The two tool parts 2, 3 are identical in shape and provided with a cutting edge and a gear rack. The first tool part 2 has a first cutting edge 4 and a first gear rack 5, while the second tool part 3 has a second cutting edge 6 and a second gear rack 7, see Figure 2. Said components can also be seen in Figure 2. As is also clear in Figure 2, each tool part is in the shape of a "U", the legs of the "U" being situated in two separate, but parallel, planes. The two tool parts can thus be fitted together to form a cooperating unit and are moved towards or away from each other in transverse direction.
The combined tool parts thus form a rectangular through-aperture defining a cutting area 8 which decreases in length as the parts move transversely towards each other and increases in length as the parts move transversely away from each other. In the embodiment shown in Figure 2 the aperture is defined by the cylindrical short sides of the parts, provided with cutting edge and mating surface, and by the smooth long sides of the parts, provided with teeth.
A centrally mounted and journalled drive shaft 9 passes through the cutting area 8 and, within the cutting area, has a cylindrical cutting and drive part 10 with a larger diameter than the actual shaft 9, which is rigidly connected to the shaft 9.
The first tool part 2 with its edge 4 defines a left first cutting member and the second tool part 3 with its edge 6 defines a right first cutting member. These two tool parts 2, 3 with their edges 4, 6 thus define the two first cutting members 2, 3 and 4, 6, respectively of this embodiment. At the transition from the drive shaft 9 to said part provided with a cylindrical cutting edge the cutting and drive part 10, see Figure 3, defines a second cutting member 11 towards which both said first cutting members move during their transverse displacement, thereby forming a shear on each side of the shaft 9. The drive part 10 is also provided with a pinion 12, see Figures 2 and 3, in toothed engagement with the first gear rack 5 on one side of the shaft 9 and in simultaneous toothed engagement with the second gear rack 7 on the other side of the shaft 9.
Upon rotation of the drive shaft 9 in the direction indicated by the arrow, both tool parts 2, 3 will move towards the second cutting member 11, their edges 4, 6 forming a shear against the cutting edge on each side of the shaft 9. The aperture thus forms a cutting area which in this embodiment consists of a part on one side of the shaft and a part on the other side of the shaft. When cutting has been performed, the two first mating surfaces 13 on the first cutting member are moved towards a cylindrical second mating surface on the second cutting member upon continued translation movement.
When using the cutting and pressing tool 1 in a tying tool the function is such that the two tool parts 2, 3 are slidably journalled in a tool housing, not shown, for transverse movement perpendicular to the rotating shaft. A tying wire 15 is threaded first into one part of the cutting area 8 on one side of the shaft 9, around one or more objects 16 to be tied, and back through the other part of the cutting area 8, preferably on the other side of the shaft 9. It is also possible to draw the tying wire 15 back through the cutting area 8 on the same side of the shaft 9. When the tying wire 15 has been drawn into this cutting area, tying is performed by rotating the shaft 9 in the direction indicated by the arrow in Figure 3, whereupon the parts 17 of the tying wire 15 are first cut off by the edges 4, 6 being displaced towards the cutting edge of the second cutting member 11. Secondly, upon continued rotation of the shaft 9 the
two parts 17 of the tying wire will be clamped firmly between the first mating surfaces 13 and the second mating surface 14. Thirdly, further continued rotation of the shaft 9 will cause the parts 17 of the wire to be twisted as they accompany the rotation of the shaft 9. The fourth stage occurs when the wires have been sufficiently twisted and the direction of rotation of the shaft 9 is reversed, thereby separating the tool parts 2, 3 from each other so that the first mating surfaces 13 are also separated from each other, thus loosening their grip around the parts 17. The tying operation is now complete. Rotation is preferably achieved by means of a chargeable drill with stepless and reversible speed.
The cutting and pressing tool shown in Figures 1-3 indicates one of several possible embodiments of a tying procedure in which the translation movement occurs perpendicularly to the rotating shaft, within the scope of the appended claims.
Figure 4 shows a tying tool according to the present invention, operating in accordance with an alternative procedure according to the invention. The tool comprises a tool housing 18 which in the embodiment shown is provided with an internally cylindrical envelope surface. The exterior of the tool housing may also be cylindrical, but provided with a friction- increasing surface, comfortable to hold. A threaded leading spindle 19, is arranged as the shaft 9 in one end of the tool housing 18 and provided with a hexagonal connection part 20, e.g. the chuck of a drill. The other end of the tool housing 18 is provided with a central slot 21 extending from the centre of the end and out through its periphery inwardly towards the tool, preferably in an arc out to the side of the tool in a left slot 22 for use by a right-handed operator passing both parts of the tying wire through this slot with his left hand and with his right hand operating the drill connected to the connection part to turn clockwise. A right slot 23 is arranged correspondingly from the central slot 21 in an arc out through the opposite side of the tool, the right slot being used by a left-handed operator to pass both parts of the tying wire through this slot with his right hand and with his left hand to operate the drill connected to the connection part to turn anti-clockwise. The extension and shape of these slots may also be designed in many different ways within the scope of the present invention. A cutting area 22, 23 may also be defined at the left slot 22 and right slot 23 in this embodiment.
Figure 5 shows the tool according to Figure 4 from the side, the left slot 22 at the side of the tool thus running back towards the end in order to enable the tying wires to be hooked with the left hand prior to operation of the tool with the right hand. The right slot 23 on the other side of the tool is designed in corresponding manner for a left-handed operator.
Figure 6 and Figure 7 show a section along the line B-B in Figure 5, with the difference that the tool is shown open in Figure 6 and in ready cut position in Figure 7. The leading spindle
19 with the hexagonal connection 20 at one end is arranged as a screw in a screw-nut mechamsm in which the nut corresponds to a threaded end part in the form of a nut 24 rigidly
joined to the tool housing 18. The other end of the leading spindle 19 is designed as a socket joint 25, or having some other form of coupling for placement in a first cutting member 26 movement transversely in the tool housing and provided with a ball socket corresponding to the socket joint 25. The leading spindle 19 is secured in the movable first cutting member 26 by means of a grub screw 27. Upon rotation of the leading spindle 19, therefore, the movable first cutting member 26 is moved transversely in the tool housing 18. The movable first cutting member 26 is cylindrical and is provided with an annular cutter 28. A cylindrical, stationary second cutting member 29, provided with an annular cutting edge 30, is also arranged in the other end of the tool housing 18. For improved function, the annular cutter 28 and/or the annular cutting edge 30 is provided with a serrated edge. Figure 6 also shows how the parts 17 are placed in the central slot 21 and drawn out through the left slot 22.
The function of the tying tool according to this embodiment is that from the open position shown in Figure 6 with the parts 17 placed in the left slot 22, for instance, a drill connected to the connection part 20 of the leading spindle 19 is run clockwise so that the first cutting member 26 is moved transversely in the direction of the second cutting member 29, after which the parts 17 are cut off in a first stage between the cutter 28 and the cutting edge 30, see Figure 7. Upon continued transverse movement the parts 17 will be clamped in a second phase between a conical mating surface defined by a first mating surface 33 on the first cutting member 26 and a conversely conical mating surface defining a second mating surface 34 on the second cutting member 29. Upon further continued rotation of the leading spindle 19 the entire tool housing 18 will start to rotate and in a third phase will twist the clamped parts 17. In the same way as with the tool shown in Figures 1-3, the direction of rotation of the shaft 9 is reversed in a fourth phase when the wires have been suitably twisted, thus separating the first cutting member 26 from the second cutting member 29 so that the mating surfaces 33, 34 are also separated from each other and release their grip on the parts 17. The tying operation is thus complete. The first cutting member 26 may either be controlled or free running as regards rotation in the tool housing 18. Upon transverse movement of the first cutting member 26 towards the second cutting member 29, rotation of the tool housing 18 is prevented by the operator holding the parts 17 firmly hooked with one hand in the left slot 22 or by the operator restraining the tool housing 18 with one hand. After cutting and pressing together, the entire tool housing will rotate to effect twisting, after which the tool housing is again restrained during separation through reversing the direction of rotation.
The above-mentioned reversal of the direction of rotation in the embodiments described above is achieved by stopping the drill, switching it from clockwise to anti-clockwise rotation and then re-starting it.
Figure 8 shows that the second cutting member 29 is split down to the centre in order to allow insertion of the parts 17 into the central slot 21 down to the centre of the cutting member in a
recess 35. In the embodiment shown the conversely conical second mating surface 34 is provided with a friction-increasing texture in the form of sector rings 36.
Figure 9 shows that the first cutting member 26 is completely cylindrical, its cutter 28 and mating surface 33 being in the form of an unbroken ring and cone, respectively. In the embodiment shown the tool part 25 lacks equivalent friction-increasing sector rings 36, but may naturally be provided with these, or other types of friction- increasing textures.
Within the scope of the appended claims the cutting tools and tying tool including these cutting tools may be designed in many ways not specifically shown here, such as with angles on the mating surfaces, cutting edges, drive-shaft connections, spindle adapters, etc.