The present invention relates to a log splitter assembly, and relates particularly, but not exclusively to a log splitter assembly for splitting logs with a blade moveable along a guide means

Logs are traditionally split by striking the log with an axe to split the log into smaller pieces of wood. However, the use of an axe can be dangerous and it is therefore desirable to split logs in a more controlled manner.

EP0783402 describes a log splitter that has a cutting blade slidably mounted on a first guide pole. The first guide pole is mounted in a base which is generally a large piece of wood. A second guide pole projects from the rear end of the blade. An impact weight is slidably mounted on the second guide pole and is arranged to strike a nylon bush mounted to the end of the blade to drive the blade along the first guide pole and into a log to split the log.

The log splitter of EP0783402 suffers from the following drawbacks. Firstly, because the blade is slidably mounted on a first guide pole and the impact weight is slidably mounted on a second guide pole which is laterally displaced from the first guide pole, a torque is exerted on the first guide pole whenever the impact weight is used to drive the blade into a log. Repeated use of the log splitter can therefore cause a torque to be applied to the first guide pole which has a loosening effect of the pole inserted into the wooden base. This effect is further exaggerated because of the distance between the blade and the first guide pole. Secondly, some of the energy transmitted from the impact weight to the blade is lost because the nylon bush placed on the back of the blade deforms outwardly when it is hit by the impact weight. The deformable bush is also prone to breaking after repeated use and therefore requires periodic replacement .

Furthermore, in the commercially available product described by EP0783402, the second guide pole projecting from the rear end of the blade is a solid bar having a diameter of 12mm. This means that it is not strong enough to be used as a lever for the blade and also cannot be used to steer the blade. The blade is therefore free to run wherever it wants.

US4274458 describes a log splitter having a blade slidable along a guide post, wherein the guide post is connected to a base on which a log is to be placed. To split a log, a user places the log on the base and slides the blade into a position resting on top of the log. The user then strikes the back of the blade with a sledge hammer to drive the blade into the log. If the blade becomes embedded in a log to an extent that the top of the blade is flush with the top surface of a log, the blade can no longer be reached with the sledge hammer. To solve this problem, a blade extension is slidably mounted on the guide post and can be swung into a position resting on the top of the blade. The extension can then be hit with the sledge hammer and the blade driven further into the log to split the log.

The apparatus of US4274458 suffers from the drawback that striking the blade with a sledge hammer exerts a considerable force on the blade and a torque on the guide post, because the blade is laterally displaced from the guide post. This therefore can cause bending of the guide post and damage to the blade. The use of a sledge hammer can also be dangerous.

US1304528 describes a log splitting machine comprising a cutting member having a blade for piercing and splitting a log. The cutting member rests on a track on a large wooden frame. heavy striking member is lifted along the track by a cable and pulley system and dropped to impact the cutting member to split a log.

This apparatus suffers from the drawback that it is heavy and is formed from a large wooden frame. It also requires a pulley system to lift the heavy striking weight.

Consequently, this apparatus is not particularly portable and unsuited for use in splitting smaller logs and kindling.

A preferred embodiment of the present invention seeks to overcome the above disadvantages of the prior art.

According to the present invention, there is provided a log splitter assembly comprising: guide means to which a cutting blade member is slidably mountable to be moveable along a longitudinal axis defined by the guide means; an impact weight slidable along the guide means, wherein the impact weight is arranged to be dropped along the longitudinal axis defined by the guide means to impact a portion of the cutting blade member to drive a cutting edge of the cutting blade member into a log; wherein the guide means comprises a first tubular member mounted to the cutting blade member, wherein the impact weight is slidably mountable on the first tubular member; and a base pole member over which the first tubular member is telescopically and slidably mountable.

This provides the advantage that since the cutting blade member and impact weight are moveable along the same longitudinal axis, no torque is exerted on the assembly during the splitting of a log. This prevents bending of the guide means and therefore prolongs the lifetime of the assembly.

This also improves the cutting action of the log splitter assembly because energy is not wasted by being transferred to a laterally displaced guide post.

This also provides the advantage of a telescoping guide means arrangement that enables the assembly to act along a common longitudinal axis. This increases the protability of the assembly

The cutting blade member may be disposed at a location along the first tubular member such that if the end of first tubular member is rested on a surface, the cutting edge of the cutting blade member is located above the surface.

This provides the advantage of increasing safety because the vertical displacement of the first tubular member relative to the cutting blade member stops the cutting blade member from contacting the base surface. This means that if a user places his or her hand on the base surface and cutting blade member was then dropped along the guide means, because the cutting blade member cannot contact the base surface there would be no risk of injury.

The base pole member may comprise an end having a screw to enable the screw to be driven into a base surface to anchor the end of the guide means in the base surface in use.

This provides the advantage of a convenient and straightforward means of mounting the base pole member in a surface, such as a piece of wood. This also provides the advantage that the base pole member can be easily removed and placed in a different location if required.

The assembly may further comprise at least one tubular extension portion mountable to the first tubular member to increase the length of the first tubular member.

This provides the advantage of enabling adaptation of the log splitter assembly for use with larger sizes of log. For example, if a larger or harder type of log is required to be split, a tubular extension portion can be mounted to the first tubular member to increase the height from which the impact weight can be dropped to increase the force applied to the cutting blade member.

The first tubular member and/or at least one tubular extension may be formed from metal tubing at least 25mm in diameter .

This provides the advantage that the first tubular member can be used as a lever should the cutting blade member become stuck in a log. If the cutting blade member becomes stuck in a 1ος, the first tubular member (and at least one tubular extension if connected) can be telescopically lifted off the base pole member to carry the log in which the blade is stuck with the blade. Since the metal tubing is at least 25mm in diameter, it is strong enough for the first tubular member to be used as a lever to prise the blade out of the log.

The assembly may further comprise a washer mountable between the first tubular member and at least one tubular extension to provide a stop to prevent removal of the impact weight from the guide means and provide a surface on which to impact the impact weight to assist removal of the cutting blade member from a log in use.

This provides the advantage of a convenient means for preventing removal of the impact weight and also providing a means to assist removal of the blade from a log.

This also provides the advantage that the washer is mountable over the base pole to rest on the top surface of the base to prevent the first tubular member from contacting the base surface. This means that the first tubular member cannot be driven into the base surface. This also prevents the cutting blade member from contacting the base surface and thereby splitting the base.

In a preferred embodiment, the cutting blade member further comprises a bush comprising: an elastically deformable portion having first and second ends, wherein one of the first and second ends is arranged to be impacted by the impact weight; and a rigid housing at least partially encapsulating the elastically deformable portion between the first and second ends to prevent outward deformation of the elastically deformable portion.

This provides the advantages of both increasing the force applied to the blade by the impact weight and increasing the lifetime of the log splitter assembly. Since the elastically deformable portion of the bush is prevented from deforming outwardly by the rigid housing, energy is not lost by outward deformation of the elastically deformable portion and this energy is therefore transmitted downwardly to the cutting blade member. Also, since the elastically deformable portion is prevented from moving outwardly, it is less prone to breaking and therefore does not need to be replaced frequently.

The rigid housing may comprise an outer cylindrical housing portion and an inner rigid bush arranged to slidably engage the guide means, wherein the elastically deformable portion is mountable between the outer cylindrical housing portion and inner rigid bush.

The cutting blade member may comprise a widened wedge portion disposed adjacent the cutting edge.

This provides the advantage that the cutting blade member provides both a piercing action on the upper surface of the log being split and also provides an improved splitting action because of the widened wedge portion. This makes the cutting blade member more likely to split a log in fewer impacts from the impact weight. The assembly may further comprise a second cutting blade member mountable to a base surface in use.

This provides the advantage that should the cutting blade member become stuck in a knot in a log being split, the force generated by dropping the impact weight will be transmitted on to the second cutting blade member to continue to split the log. This therefore significantly decreases the probability that the cutting blade member will become stuck in a log.

The assembly may further comprise a tubular spacer mountable over the base pole member to prevent the cutting blade member and second cutting blade member from coming into contact.

This provides the advantage of increasing safety because the tubular spacer member prevents the blades of the respective cutting blade member and second cutting blade member from coming into contact. This means that if for example a user placed his or her fingers over the lower blade of the second cutting blade member and the upper cutting blade member was then dropped along the guide means, because the blades cannot touch there would be no risk of injury to the user's hand.

A preferred embodiment of the present invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings in which:

Figure la is a side view of a cutting blade member and first tubular member of a log splitter assembly according to the present invention; -Si- Figure lb is a cross section taken along line D-D of Figure la;

Figure 2 is a top view of the cutting blade member and first tubular member of Figure la;

Figure 3a is a close up view of the cutting blade member of Figure la;

Figure 3b is a cross section taken along line A-A of Figure 3a;

Figure 4 is a front view of the cutting blade member;

Figure 5a is a side view of a base pole member of the guide means;

Figure 5b is a close up view of detail C of Figure 5a;

Figure 5c is a close up view of detail B of Figure 5a;

Figure 6a is a side view of a fully assembled log splitter assembly according to the present invention;

Figure 6b is a front view corresponding to Figure 6a;

Figure 7a is a side view of a tubular extension portion;

Figure 7b is a close up of detail A of Figure 7a;

Figure 8a is a perspective view of an impact weight of a log splitter assembly of the present invention; Figure 8b is a cross sectional view of the impact weight of Figure 8a;

Figure 8c is a top view of the impact weight of Figures 8a and 8b;

Figure 9a is a perspective view of an elastically deformable portion of a bush; Figure 9b is a cross section of the elastically deformable portion of Figure 9a;

Figure 9c is a top view of the elastically deformable portion of Figures 9a and 9b;

Figure 10a is a perspective view of an inner rigid bush arranged to be placed on the interior of the elastically deformable bush portion of Figure 9a to 9c;

Figure 10b is a cross section of the bush portion of Figure 10a;

Figure 10c is a top view of the bush portion of Figure 10a and 10b;

Figure 11a is a perspective view of a washer to be placed between tubular portions of the guide means and over the base pole member;

Figure lib is a cross section of the washer of Figure 11a;

Figure 11c is a top view of the washer of Figures 11a and lib; Figure 12 is a perspective view of the log splitter assembly of the present invention; Figure 13 is a close up view of the cutting blade assembly and impact weight of Figure 12;

Figure 14a is a perspective view of a second cutting blade member;

Figure 14b is a top view corresponding to Figure 14a;

Figure 14c is a first side view corresponding to Figure 14a; Figure 14d is a second side view corresponding to Figure 14;

Figure 15 is a perspective view of a log splitter assembly according to the present invention using a second cutting blade member;

Figure 16 is a side view of Figure 15a; and

Figure 17 is a front view corresponding to Figures 15 and 16.

Referring to Figure 12, a log splitter assembly 2 comprises guide means 4 to which a cutting blade member 6 is slidably mountable to be moveable along a longitudinal axis X defined by the guide means 4. An impact weight 8 is slidable along the guide means 4, wherein the impact weight is arranged to be dropped along the longitudinal axis X defined by the guide means 4 to impact a portion of the cutting blade member 6 to drive a cutting edge of the cutting blade member into a log 10. Referring to Figure la, a first tubular member 12 forms part of the guide means 4. The first tubular member 12 is mounted to the cutting blade member 6. For example, first tubular member 12 can be welded to cutting blade member 6. The cutting blade member 6 is disposed at a location along the first tubular member 12 such that if the end of first tubular member is rested on a surface, the cutting edge 20 of the cutting blade member is located above the surface. Preferably, the distance between the lower end of the first tubular member 12 and the cutting edge 20 is at least 25mm.

Referring to Figures lb, 7a and 7b, a threaded portion 14 is provided at an upper end of the first tubular member 12 to enable the first tubular member 12 to be connected to at least one tubular extension 16. An internal thread 18 is provided at the lower end of tubular extension 16 to be interconnected with thread 14 of tubular member 12.

Referring to Figures 1 to 4, the cutting blade member 6 comprises a cutting edge 20 and a widened wedge portion 22. The cutting edge 20 is arranged to pierce the top edge of a log 10 and the widened wedge portion 22 is arrange to force the log apart to split the log 10. The cutting blade member 6 comprises first and second arm portions 24 and 26. Second arm portion 26 is connected to an outer cylindrical housing portion 28 of bush 29 which is arranged coaxially with first tubular member 12.

Referring to Figures 3a, 3b, 9a to 9c and 10a to 10c, bush 29 comprises outer cylindrical housing 28 which at least partially encapsulates an elastically deformable portion 30 formed from nylon or another deformable material such as rubber. Inner rigid bush 32 is arranged in sliding engagement with the first tubular member 12 and is formed from steel or another substantially rigid material. Consequently, the bush is formed from an elastically deformable portion 30 having first and second ends, one of which is arranged to be impacted by impact weight 8. Elastically deformable portion 30 is encapsulated in a rigid housing between the first and second ends of portion 30 to prevent outward deformation of the elastically deformable portion 30 relative to the longitudinal axis.

Referring to Figures 5a to 5c, a base pole member 40 forms part of the guide means 4 and comprises a screw 42 mounted to the lower end of the base pole member to enable the base pole member 40 to be driven into a base surface such as a log. The upper end 44 of the base pole member 40 may comprise an internal hex shaped portion to enable the screw 42 and pole 40 to be rotated to drive the base pole member 40 into a piece of wood for use as a base.

Referring to Figures 8a to 8c, impact weight 8 is generally cylindrical in shape and comprises an internal bore 9 shaped to enable the impact weight 8 to be slidable along the guide means 4, i.e. generally downwardly along axis X of Figure 12. Preferably, the impact weight 8 is slidably mountable on first tubular member 12 such that if the impact weight 8 is dropped along first tubular member 12 (which in turn is telescoped on base pole member 40) the impact weight 8 will impact the elastically deformable portion 30 of the bush of the cutting blade member 6 to impart impacts to the cutting blade member 6. Consequently, in a preferred embodiment the guide means 4 is formed from first tubular portion 12 and base pole member 40. First tubular portion 12 is shaped to be slidably and telescopically moveable over base pole member 40 and the impact weight is arranged to telescope on the first tubular portion 12 and any tubular extensions 16 connected to first tubular portion 12. However, it should be understood that the guide means 4 could also be formed from any other arrangement using a single longitudinal axis. For example, a rail could be used as a guide means 4 and the other parts could have runners to slidably engage the rail.

Referring to Figures 11, 13 and 7, washer 46 is arranged to be mountable between the first tubular member 12 and a tubular extension portion 16. The washer can be placed over the upper threaded end 14 (Figure lb) of first tubular member 12 and then the tubular extension 16 screw downwardly to trap the washer 46 in the joint. The washer therefore provides a stop to prevent removal of the impact weight 8 from the guide means 4 and also provides a surface 47 on which to hit the impact weight against to assist removal of the cutting blade member from a log.

Referring to Figures 11 and 12, washer 46 is also arranged to be mountable over base pole member 40 with surface 47 in contact with the base 41. The first tubular member 12 therefore impacts surface 48 and is prevented from contacting the base 41.

Referring to Figures 6a and 6b the fully assembled log splitter assembly 2 is shown. Although the log splitter assembly 2 can be used free handed, it is preferably anchored by mounting the base pole member 40 in a base such as a piece of wood 41. In order to do this, a pilot hole 43 is be drilled in the wood 41 and the base pole member 40 embedded using screw 42 to a depth of approximately 100mm. In the embodiment shown, the base pole member has a length of 650mm which leaves a length of 550mm exposed above the upper surface of the wood 41.

The first tubular member 12 connected to cutting blade member 6 is then be telescopically slid downwardly over base pole member 40. At least one tubular extension 16 can be mounted to first tubular member 12 to increase the length of the guide means 4 and the impact weight 8 can then be dropped down over first tubular member 12 (and extension 16 if in use) . The first tubular member 12 in the embodiment shown is 650mm in length. Consequently, since the base pole member 40 extends 550mm above the base wood 41, there is 100mm clearance between the top of the base pole member 40 and the upper end of first tubular member 12 if the cutting blade member 12 is at its lowermost position.

Referring to Figures 12 and 13, the splitting of a log by log splitter assembly 2 will now be described. The first tubular member 12 (and extension 16 if in use) is telescoped over base pole member 40. A log 10 is then placed on base 41 and the first tubular member 12 lifted to the configuration in which the cutting edge 20 of the cutting blade member 6 rests on the top of the log 10. The impact weight 8 is then lifted upwardly along the first tubular member 12 and dropped to impact the elastically deformable portion 30 of bush 29 of cutting blade member 6. This drives cutting blade member 6 down into the log 10 to split the log. Should the cutting blade member 6 become stuck in the log 10, a user can lift first tubular member 12 off of the base pole 40. This will carry the cutting blade member 6 and log 10 in which the blade is embedded off base pole member 40. Since the tubes 12 and 16 are formed from metal tubing having a diameter of at least 25mm, the tubing is strong enough to be used as a lever to lever the cutting blade member 6 out of the log 10. Alternatively, referring to Figure 13, to remove the blade 6 from the log 10 a user can impact the upper end of impact weight 8 on washer 46 which will bring the blade 6 out of the log 10.

Referring to Figures 14 to 17, the log splitter assembly 2 can be improved by the use of a second cutting blade member 60. Second cutting blade member 60 comprises a base 62 having holes 64 for screws. Consequently, the base 62 can be screwed into the wood base 41. The second cutting blade member 60 comprises an upright blade 66.

The first stages of cutting a log 10 using the log splitter assembly 2 incorporating the second cutting blade member 60 are the same as described in connection with the example of Figures 12 and 13. These steps are to place the log 10 flat on base 41 and drive the cutting blade member 6 into the top of log 10 using impact weight 8. Once the cutting blade member 6 is lodged in log 10, the log 10 can be lifted by lifting first tubular member 12. The first tubular member 12 can be rotated to place the lower edge of log 10 on top of second cutting blade member 60. The log 10 is then in the position shown in Figures 15 to 17 with a blade protruding into both the upper and lower edges of the log 10. The impact weight 8 can then be dropped along the guide means 4 to drive the upper blade 6 into the log 10 to split the log. The lower end of the log 10 will also be penetrated by the blade 66 of second cutting blade member 60. Consequently, if one of the blades becomes stuck in a knot in the wood, the other of the blades will continue to be driven into the log due to the impact force generated by weight 8 to split the log. A tubular spacer 68 is mountable over the base pole member 40 to prevent the cutting blade member 6 and second cutting blade member 60 from coming into contact.

The above embodiments have been described by way of example only and not in any limitative sense, such that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims .