The object of this invention is a manual impact tool, by means of which many tasks requiring strength and liable to accidents, can be carried out without an external power supply. Examples of such tasks are splitting and debranching logs, breaking and cutting frozen earth, stone, concrete or silage. The invention also concerns the blade construction used. The invention also concerns a method and accessory device, especially for splitting wood.

The basic principle of the impact bar is described in and known from numerous patents, some of which are very old, including US patents 4429727, 4327787, 4379475, 4308903 and 4294298. All of them feature variations of the same basic solution, which are clumsy, expensive, often heavy, and in practice do not operate as intended. This has prevented their widespread use by the general public. Many of the solutions demonstrate a lack of knowledge of physics on the part of the inventor, such as the impacting component having a small weight in relation to the mass to be struck, as in the case of US patent 4 470440. However, there is no known solution, in which the weight of the combined blade and blade holder has been minimized in relation to the striker, while also ensuring that the wood-splitting blade meets practical requirements.

In many solutions, such as those in US patents 4 405 005, 4 305 192, 4 431 0404, 4294 298, 4470 440 and 4 3227 787, the blade is attached to the inner part of a telescope, which must be both light and durable. This solution prevents the impact bar being used as a torque tool, which is one application of the device. Some solutions, such as US patent 4429 727, also have handles welded transversely to the direction of impact, in practice, this will not work, because the sharp impact also impacts sharply on the user's hands, so that the solution does not meet even the most elementary ergonomic requirements. Further, the crosswise handles complicate the device, making it more expensive and difficult to transport and store.

In addition, most of the devices lack a practical arrangement to connect the blade and telescopes to each other when moving the device from one job to another, to

say nothing of a practical snap-fit system for changing blades.

As the size and weight of the user varies, the weight of the impact component must also be varied. Various complicated arrangements have been made to solve this problem.

Another problem has also been the fact that the impact bars described could only be used with an impact tool method. However, if a range of efficient tools is developed for the device, their use need not be limited to this area. Properly realized, many of the tools can also be used as extension arm tools, without the relatively heavy striker component. This arrangement can multiply the uses of certain tools, effectively exploit the snap-fit system and substantially expand the use of the whole method. An example of such expanded applications is the increasing use of tools in renovation work in old buildings, such as the removal and breaking of floor finishes, rendering and concrete structures. These devices are known as pneumatic strippers.

Correctly implemented, the impact bar system can also have further possible uses in the above field, as it is economical and independent of a source of compressed air, making it very suitable for small building sites. This also applies to the use of ice-removal bars, crowbars and silo cutters. Besides, many strippers at present used for such work have a totally inadequate impact force.

A very large impact force is required when splitting logs and driving the steel points of fenceposts into the ground.

This invention is intended to create a simple, highly simplified, economical impact tool, which as far as possible eliminates all the aforementioned and other drawbacks and limitations. It is also intended to create a method and accessory for use with the impact bar when splitting wood.

The above and other advantages of this invention have been achieved in the characteristic manner described in the accompanying Claims.

The invention is described in greater detail with reference to the accompanying drawings, in which:

Figure 1 shows a side view of the first part of the tool according to the invention;

Figure 2 shows the second and third part of the tool according to the invention according to the invention, which here are located separately from each other;

Figure 3 shows an assembled device according to the invention;

Figure 4 shows another embodiment of the device according to the invention;

Figure 5 shows another example of the type of joint used in a device according to the invention;

Figure 6 shows a cross-section of the joint in Figure 5;

Figure 7 shows a series of different shapes of blade for use with a device according to the invention;

Figure 8 shows a diagram of the blade construction according to the invention, seen from the side;

Figure 9a shows an illustration similar, but at right angles to Figure 8;

Figure 9b shows an alternative embodiment to that in Figure 9a;

Figure 10 shows one extremely simplified accessory for splitting wood;

Figures 11a - 11b show another embodiment of the accessory according to the invention, seen in two views at right angles to each other;

Figures 12a - 12d show a third embodiment of the accessory according to the

invention, seen from the side, end, top and correspondingly opened;

Figures 13a - 13d show a fourth embodiment of the device according to the invention, seen from different directions;

Figures 14a - 14c show a fifth embodiment of the accessory according to the invention, seen from different directions;

Figures 15a - 15c show a sixth embodiment of the accessory according to the invention, seen from different directions;

Figures 16a - 16b show yet another embodiment of the accessory of the invention in two different operating situations;

Figures 17a and 17b show the construction of yet another accessory according to the invention, seen from two different directions; and

Figures 18a - 18b show the final embodiment of the invention, in the same manner as Figure 17.

Although the accompanying drawings are referred to in the description of the invention in the following text, they show only one embodiment of the invention, there being numerous possible variations, which nevertheless remain within the scope of the protection of the invention, as described in the Claims.

Figures 1 and 2 show the components comprising, in principle, a device according to the invention. Thus, device 1 consists of a relatively massive impact bar 2, a tube-like component 3 made of relatively thin material and an appropriate blade component 4. The impact bar 2 is divided into a visible part 21 and a lower part 22, which lies inside the tube. When the device is assembled, as shown in Figure 3, blade 4 is secured to the lower end of tube 3, by means of a suitable snap-fit connector, for instance 31 , 41 , or welded directly to the lower end of the tube. Here, the impact bar 2 is placed inside tube 3, from its lower end, after which the tool is

ready for use.

To use the tool according to the invention, blade 4 is set at the desired place on the surface of the object to be split or otherwise worked on. One hand grips tube 3, while the other hand grips the upper end 21 of the impact bar. Impact bar 2 is raised to a suitable height and then impelled downwards by hand, when it strikes the upper end of blade 4, causing the blade to penetrate the object. The desired number of impacts is given in this way.

If more force is desired, both hands can be used to provide the impact. This is particularly possible, when the blade 4 has already sunk into the object being worked on and therefore remains securely in place. However, even when using two hands, it is possible to guide precisely a tool according to the invention, even if the entire device is raised and impelled into the object.

Coloured marks 23 at the lower end of the bar can be used to indicate the movement of the impact bar 2 before impact. When the bar is drawn out of the tube, these marks become visible at the upper end of the tub 3, showing how far bar 2 has been pulled out. Various retaining devices 32 can also be used to prevent bar 2 slipping accidentally out of tube 3.

There can be one or more grip components on the outside of tube 3, to ensure a good grip, as shown in detail in the drawings. The visible part of impact bar 2 can also be given a grip surface 33 or similar, to improve its appearance and practicability.

Figures 1 - 3 show clearly that the ratio of the size of tube 3 and also of the lower part 22 of the impact bar to the size of the upper part 21 can be freely varied, to suit the intended use. It is also obvious that the diameter of tube 3 and bar 2 can be varied without limit, so that an appropriate device can always be created by using different dimensions.

Figure 3 shows that the upper end of the tube 3 and the lower end of the upper part

21 of impact bar 2 are shaped and dimensioned to avoid accidents, such as the user's hand being caught between the components during impact. One solution is shown in Figure 3, where spacers 24 are used to prevent nipping between the components. If necessary, a sheath of soft plastic can be used on top of spacer 24.

Figure 4 shows another embodiment of the device according to the invention. This differs from that described above in that an impact bar component is used, comprising both the component that enters tube 3 as described above and a collar 25 lying outside tube 3, which increases the weight of the impact bar. This collar is suitably secured to impact bar 2. This extra collar can be dimensioned as desired, for example as in Figure 4, where it extends nearly the whole distance downwards, shorter alternatives being naturally possible.

In the embodiment described above, it advisable in practice to dimension the outside of the device to provide a suitable grip. This usually means reducing the dimensions of the inner components. The grip component can be suitably sprung, to protect the user's hand from vibration. A spring, rubber or other cushion 26 is shown by way of example.

Because in this embodiment the main impact mass is located in the outer tube 25, it is possible to replace the upper end 21 of the impact bar with a connector which, as such, does not have a significant mass.

It is obvious that the embodiment in Figure 4 must have locking 27 between the outer collar 25 and tube 3, otherwise the device would not operate as desired. Locking 27 of this kind can be appropriately arranged to operate manually, for example. Operation is easy and natural, because when working, the hand is in any event placed more or less at the height of the possible locking device. A solution can be imagined, for example, in which gripping the locking device by hand locks it automatically when the device is raised, impact opening it again. Other kinds of semi or fully automatic operations can be linked to the locking device.

Figures 5 and 6 show a partial vertical section and corresponding cross-section A

B A of one way of creating the attachment between tube 3 and blade 4. In this snap- fit system, the blade 4 is thought of as fitting like a collar over the lower end of tube 3. Blade 4 has a sprung connector piece 41 , which presses into a slot in tube 3 when the blade is pushed and twisted onto tube 3, remaining on top of tube 3 behind counterpiece 34, thus preventing the unintentional movement of the blade when working.

It is obvious, that in various technical fields there are many different ways to create a separable snap-fit between two pieces. Thus, one versed in the art will in practice apply known solutions to make the joint, one possible alternative being a joint with a spring effect between the tube 3 and the blade 4. This both saves the user's hands and increases the efficiency of the work.

One example of this type of spring effect in the aforementioned joint arises when a bend is made in the connecting piece, which is itself flexible. This bend can flex under impact so that the connection between tube 3 and blade 4 first of all gives way and then forms a firm connection between the components.

Figure 7 shows a series of different blades for use in a system according to the invention. Alternative a shows a crowbar-like device, b, for example, a stone chisel type solution, c is good for splitting wood, d and e show different kinds of bark spuds or similar, while alternative f shows a plate-like solution, which can be used to compact earth.

Figures 8, 9a and 9b show the basic principle of a blade construction according to the invention. Thus, blade 4 comprises two main parts, a base part 42, made particularly from a flattened tube-like blank, and thickening parts 43 welded to it, these being located in the upper area of the blade, to create a powerful outwards pressure, for example, when splitting wood. The relevant construction is very light, but strong. In addition, it only needs a minimum amount of welding, at a point where it can be easily carried out.

The blade described above can be detachable, or else permanently attached to

tube 3. In one embodiment held to be excellent, the method is even to make blade 4 from the same tube structure as tube 3. For example, the construction can be made by slotting the tube transversely at a suitable point, so that the thickening part 43 can be inserted in the slot with such additional reinforcements as can also act as impact points for the impact bar, after which the parts are welded together. The end can be flattened before this. An additional advantage of the construction described above is the more or less oval cross-section of the blade, which makes a very suitable device for spreading force evenly when splitting wood.

It is obvious that a device according to Figures 8 and 9 can include a snap-fit section 41 , as shown in Figure 9b or else lack this, in which case the blade can be welded directly to tube 3. The construction of the snap-fit component can include a tubular connection piece, as shown in Figure 9b. Reference number 45 shows the lower end of the connector tube reinforced to withstand impact.

The shape and extent of the thickening parts 43 are selected appropriately, those shown being only an example and not the sole alternative. Thus, thickening part 43 can also be clearly narrower than the blade proper. Similarly, its attachment to base 42 can be strengthened by slotting or in other known ways.

Thus, the above description is of a device that is extremely serviceable, thanks to its adaptability and diverse uses. Using it, an optimal result can always be achieved by taking the desired weights and dimensions into account. A device, or range of devices, according to the invention are sufficiently simple to be easy to use, economical to manufacture and reliable in operation. There is also little danger of breakage, as tube 3 always gives internal support to impact bar component 22, which is made of sturdier material.

When using a device according to the invention, it is easy to work safely, as it is not possible to strike a hand or leg. Work accidents are quite frequent when an axe is used.

There are numerous possible variations of the device described above, while

remaining within the scope of protection of the invention. Though a device according to the invention can be easily and safely moved from place to place, by simply taking hold of the tube and moving it, separate locking can also be used between the impact bar 2 and the tube 3, to ensure that the components do not separate when being moved. This locking device can be of any type whatsoever.

It should also be noted that the tube and blade of a device according to the invention can easily be attached to a handle component, which is fitted as an extension to tube 3, but is a light tube-like piece acting only as a handle and not as an impact mass. This alternative can be used for lighter work.

The following description is of an accessory designed to facilitate work with an impact-bar type tool according to the invention. Figures 10 - 18 illustrate the method of working according to the invention. They are only intended as an example of the embodiments of the invention, and as can be clearly seen from the following, only the user's imagination restricts the practical applications of the invention. In addition, it should be noted that the dimensions and other characteristics in the illustrations are not necessarily the same as those used in practice.

Figure 10 shows how an accessory, according to the invention, for splitting wood can be made from at least one car or other vehicle tyre 102, 102', inside of which one or more logs 103 to be split can be placed. The figure shows two tyres, placed on top of each other and bound together in a suitable manner. A single wide tyre may suffice, but, depending on the size of the tyres, there may also be several on top of each other. Figure 10 also shows how the tyres can be easily bound together using a ring 107 with straps 108 attached to it, which conveniently press the tyres together.

Figures 11a and 11b show two different views of one embodiment of the invention. The device comprises ring 102, with the logs 103 for splitting gathered inside to loosely fill ring 102, providing sufficient space to allow further logs to be split, even when those already split expand. The logs can be placed inside the ring 102, when

it is on its side on the ground, or when it is vertical. Once the ring is full, a suitable tensioning band 104, or several of them, can be used to pull the logs as tightly together as possible.

The ring is then turned end-up onto a firm base, when the logs can be chopped with an impact-bar type device. Once splitting is completed, the bands are removed and the split wood can be moved, for example, to a stack from inside the ring, or alternatively, ring 102 can be returned to a vertical position and easily moved directly to a woodpile using handle 105.

If required, the above device can have supports 106, which keep the device firmly in place when it is in a vertical position.

In certain circumstances, it is obviously advantageous if ring 102 can be opened. For example, if its circumference can be increased then decreased, the logs can be easily compacted inside the ring. Figures 12a - 12d show side and end views of one embodiment based on this. The ring differs from the above description in that it now comprises rod-like components, divided into two semicircles 122 and 122'. These are jointed at point 124. Handle 125 is set so that one end joins the first semicircle at point 126 and, correspondingly, the other end joins the second semicircle 122' at point 126'. Handle 125 has, for example, a component 127, which, when rotated in one direction, lengthens the handle component, rotation in the opposite direction shortening it. Here, shortening tends to open semicircles 122 and 122', lengthening closing them. Thus, the logs can be relatively firmly compressed inside the ring and chopped using an impact bar when the tightened ring is horizontal.

Handle 125 can also operate so that turning the handle component one-quarter turn, for example, allows the ring to be opened freely to a much larger jaw, as shown in Figure 12d. The logs can then be conveniently dropped out of the ring. The ends of rings 122 and 122' can be straight, as shown, forming a firm base for the ring.

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Figures 12b and 12c also show a base section 130 for the device, which can be attached to the structure by lock 129 and also easily detached again by opening the lock. Base 130 provides a suitable even and firm base for splitting the logs.

Figures 13a - 13d show a fourth embodiment of the device according to the invention. The figures show a model that can be opened and closed as described above. The ring is formed of ring halves 132, 132', jointed around point 135. Locking device 137, which can be of any suitable type, holds the halves together when desired.

A special feature of this model are the feet 136 attached particularly to transverse pipe components 138, 138, which, when the device is turned sidewise for log splitting, act as a base. Another feature is that handle 134 is located at the end of a looped component 139, when the outermost point of loop 139 forms a third support point. In this embodiment too, suitable bands can be used to hold the logs firmly, as in Figure 13b.

Figures 14a - 14b show yet another embodiment of a device according to the invention. This differs from the previous embodiment in that it has two rings 142 and 142' connected by a rod 143, which is advantageously permanently attached to the upper ring 142 of the device when it is on its side and is inserted in hole 145 in the lower ring, permitting easy removal. If the lower end of the rod and the corresponding hole are angular in shape, rod 143 can be advantageously prevented from rotating about its axis.

When both rings are in place and joined by rod 143, the above device can be loaded with logs. After loading, binding loop 146 is advantageously used to tighten the logs in place, as described in the other above embodiments. The logs are split using an impact bar, after which the bundle of split wood, bound with the same or another loop, is left inside the loop to rest on the lower ring 142' by lifting off upper ring 142 and rod 143. Handles 144, 144' are provided for lifting. Ring 142 and rod 143 can be removed easily, because rod 143, which is quite thin and smooth, creates little resistance, though the logs are slightly compressed. Further, free

space for the rod is made by a loop-like rod seat 147, as shown in Figure 14b.

Figure 14c shows an embodiment, where the mutual positions of the two rings 142, 142' differ from the above. Thus, ring 142 can be turned around joint 148 so that when it is wished to remove the bundle of split wood or bind it with band 146, ring 142 can be turned out of the way as described. Connector arm 143 is best permanently attached to the outer surface of lower ring 142'.

Figures 15a - 15c show one way of releasing the upper ends of the split wood, for removal or binding. Rings 152 and 152' are joined together by "feet" 155, 155' and 154, the latter including a handle component for moving and carrying the device. The legs include hinges 156, around which the feet turn, upper ring 152 dropping a corresponding distance and releasing the upper ends of the logs to be handled as required. The rest of the series of figures 15a - 15c should be self-explanatory.

Figures 16a - 16b show a diagram of yet other features of the invention. They show a ring 162, which is now set on a base plate 163, with a handle 166 or a corresponding component on one side, and with protrusions 165, so that ring 162 rests on the protrusions 165. As shown, the ring itself may include a handle 164, to facilitate handling. The logs 167 can now be loaded into the ring and split there. Afterwards, ring 162 can be lowered by any means whatever onto the surface of the plate, as shown in Figure 16b, the logs now being easy to remove or bind.

A suitable system for lowering the ring can be constructed, preferably one that is in some way telescopic. The device is then locked into the upper position in a simple manner and released to the lower position for transportation.

A device according to the invention requires a suitable base for splitting. For example, the base may be made of a plate-like material, such as shuttering plywood, and set on a firm foundation. Such a base can stand, for example, on top of concrete slabs. One detail that facilitates work is to make the base considerably larger than the ring and give the edge facing the operator a handle-like grip, so that after splitting, the plate is turned to a vertical position by gripping the handle, when

the device also rises to a vertical position and can be easily removed by gripping its handle.

The base can also be provided with suitable devices to retain a ring placed on it. For example, these may be depressions in the plate. The intention is that when the device is turned on its side on top of the plate, the parts supporting the device on the base drop into the depressions and hold the device in place. Other types of "stop" for retaining the device in the required position can also be easily installed on the plate.

Figures 17a and 17b show an accessory with the same general construction as that in Figure 12, with the addition that handle 174 now has a locking device 180, which may be a screw-type knob, connected to it, to lock the half rings 172 and 172' immovably when tightened. This essentially ensures rigidity when splitting logs, which can be released from the ring by loosening locking device 180. Figure 17b also shows a base 177, which can be attached to, or released from the ring construction by lock 179.

Figures 18a and 18b show yet another variation of the above constructions. Here handle 184 is placed at the outside corner of a jointed parallelogram formed by extensions of rings 182 and 182'. This forms a construction tending to bring rings 182 and 182' closer together, when lifted by handle 184. In this embodiment too, locking device 190 can be used to lock the rings in a certain position. Similarly, base plate 187 and locking/release device 189 can be added to the construction. Reference number 188 shows a rail joining the adjacent rings, and also forming one point of support for the device as shown.

The best material for making a structure according to the invention is sheet metal, or metal in the form of a bar or tube, or a combination of these. However, many grades of plastic, for example, are sufficiently durable for the purpose described, allowing parts of devices, or entire devices to be made from plastics-based materials. At least some of the devices can include wooden parts. The choice of material is not critical.

The invention can be varied in many ways, without deviating from the scope of its protection. For example, a device according to the invention can be used to carry logs directly to where they will be burned, such as a fireplace or similar. For this kind of use, a permanent or detachable plate-like component, which fits the ring snugly and prevents debris from dropping onto the area beneath the device, may be attached to those parts of the ring that are lowest when the ring is vertical.

Widely differing devices can be used to open and shut a device according to the invention. Tens of such hinge and locking devices are known in various technical fields.

It is obvious that the shape of the ring is of little consequence. The ring can be made round or nearly round, as described above, but nothing prevents the construction of a hexagonal, square or triangular ring for the purpose described. If wished, the ring can have an extra base, which in certain circumstances can also support the splitting, when the actual base need not be so strong.

The ring of a device according to the invention can be equipped with, for example, hook-like devices in the uppermost edge when it is turned on its side, from which a net "sock" or bag can be suspended, inside which the split logs can be packed and in which they are wrapped after splitting. This produces a neat package, covered by a net or otherwise, which can thus be easily transported and stored.

Further, it is easy to make an accessory according to the invention flexible, so that the two halves composing a ring are, to a limited extent, flexible in relation to each other. In practice, this helps ensure that logs split inside the ring still have sufficient space after splitting. Similarly, because an impact tool according to the invention is, at least occasionally, struck nearly to the base, the ring's dimensional flexibility provides the tool with the necessary space at all times.