EP3842201B1

EP3842201B1 - A log splitter with a mechanical winch and operation method

Info

Publication number: EP3842201B1
Application number: EP20213338.5A
Authority: EP
Inventors: Franc Pisek
Original assignee: Pisek Vitli Krpan doo
Current assignee: Pisek Vitli Krpan doo
Priority date: 2019-12-13
Filing date: 2020-12-11
Publication date: 2023-07-12
Anticipated expiration: 2040-12-11
Also published as: EP3842201A1; HUE063503T2; SI25945A; HRP20231202T1; SI3842201T1; PL3842201T3

Description

The present invention discloses a log splitter according to the preamble of claim 1. Such a log splitter is known from the document US 2014/054526 A1 . The present invention concerns as well an operation method of such a log splitter.

Field of the invention

The present invention belongs to the field of log splitter and forestry winches, more precisely to the field of constructional details in mechanisms for ensuring safety during work with log splitters with winches. The invention relates to a log splitter with a mechanical winch and a safety mechanism for locking operation modes.

Background of the invention and the technical problem

A log splitter is a device for splitting logs or parts of logs into firewood. Usually, log splitters are equipped with a hydraulically controlled axe, which lowers and raises (vertical splitters) or travels right and left (horizontal splitters) and thus during this movement splits logs into smaller pieces. Splitters are often provided with a winch, which serves as means for pulling logs, parts of logs or wood towards the splitter. These winches may be mechanical or hydraulic.
According to the Directive for machinery safety 2006/42/ES and standards EN ISO 12100:2010, EN 609-1:2017, EN 60204-1:2006+A1:2009, EN ISO 13857:2008 as well as EN ISO 4413:2010 safe operation of machinery has to be ensured. Point 1.2.5 of the Directive sets the following: if the machine has been designed and made in such a way that it enables more modes of control or operation, wherein said modes require different safety measures and/or working procedures, the machine has to be equipped with a switch for choosing the mode of operation and the said switch has to be able to lock in any position. The chosen mode of control or operation has to disable all other modes of control or operation except the emergency shutdown. Consequently this means that the log splitter with a winch has to operate in a chosen operation mode, either as a winch or as a splitter, wherein both functions cannot be active at the same time.
The technical problem, which is solved by the present invention, is thus providing a safety mechanism enabling choice and locking of the chosen operation mode, i.e. when log splitting operation begins, the winch has to be locked and vice versa, when the winch begins to operate, log splitter activity has to be locked. Safety mechanisms are already known, however, known solution only relate to hydraulic winches on splitters, wherein their locks are achieved with electronics, sensors and valves, all controlled with a remote controller. However, this solution is not suitable for mechanical winches. Therefore, it is the aim of the invention to design a safety mechanism for locking the mode of operation, which will be exclusively adapted for mechanical winches.

State of art

Document US4561479 describes a log splitter equipped with a mechanical winch; however, the latter is not intended for pulling logs, but for raising the axe of the splitter. The solution presented in this document has been developed before the above-mentioned Directive had been issued; therefore it has many safety deficiencies. The present invention differs in that the winch has a different purpose and that it does not have a safety mechanism.
A known solution of the company Vitli Krpan shown at the web address: http://www.vitli-krpan.com/si/prodajni-program/cepilniki-drv/serija-cv/499-cv-26-k-pro, does not have a safety or a locking mechanism, which would ensure switching between the winch operation mode and the splitter operation mode. The log splitter is only equipped with a mechanical winch, operation of which cannot be locked during log splitting. The mechanical winch, on the other hand, is also not provided with additional safety mechanisms such as termination of winding when the rope comes close to the pulley; therefore work with this device is not in accordance with the above mentioned Directive and standards.

Description of the solution of the technical problem

The present invention is based on the above mentioned device of Vitli Krpan, in which the log splitter is provided together with a mechanical winch for pulling logs, which can then be split at the site. To ensure safety, a safety mechanism for locking operation mode is provided, wherein the mechanism is based on the principle of levers and locks, so that the device can operate in only one mode at a time - either as a winch or as a log splitter. The choice of the operation mode lasts for as long as work in the selected mode lasts. The technical problem is solved as defined in the independent claim, while preferred embodiments of the solution of the technical problem are defined in the dependent claims.
The log splitter used in the invention may be any known log splitter without special adaptations. It is usually designed to have an axe, movement of which can be triggered with an actuator that is activated with two handles of the log splitter. The handles are connected mechanically with the actuator as is known in the state of the art, most commonly via a lever or an additional handle. When the actuator is triggered, movement of the axe is activated, typically by hydraulic operation. The winch provided on the log splitter has all usual constructional elements of mechanical winches known to the skilled person, such as:

housing of the winch, in which the drum for winding the pulling rope is installed together with the clutch lamellae, sprocket with a chain and a brake,
rope for activation of pulling and winding the rope onto the drum, which is through pulleys connected with the clutch of the drum, and
a guide of the pulling rope and the pulling rope with an end part, which is preferably equipped with forceps for gripping a log or a part of a log.

The essence of the log splitter with the mechanical winch and a safety mechanism for locking operation mode is in that it includes the safety mechanism, which allows switching between operation as a log splitter and operation as a winch, wherein the safety mechanism is designed as a system of levers and enables two options when the device is inactive or in idle:

upon pulling a handle of the log splitter (initiating log splitting function) through a series of suitably connected levers and handles disables pulling of a rope for activation of the winch, and
upon pulling the rope for activation of the winch (initiating winch function) through the series of suitably connected levers and handles disables movement of the handle of the log splitter.

The safety mechanism is in the most preferred embodiment comprising at least the following:

a first vertical handle for choosing operation in the log splitting mode, wherein the first vertical handle is on one side connected with at least one handle of the log splitter and is on the other side connected with a lock of the winch, said lock having a shape arranged to stop movement of a winch lever upon movement of the handle of the log splitter, which disables winch operation mode, as the activation rope of the winch cannot be pulled; and
a second vertical handle for choosing operation in the winch mode, wherein the second vertical handle is on one side connected to the winch lever, which is moved upon pulling the activation rope of the winch and is on the other side connected to the lock of the log splitter, said lock having a shape arranged to disable log splitting operation, as the handle of the log splitter cannot be moved.

The described safety mechanism operates in the following manner: upon pulling of the handle of the splitter, the first vertical handle moves upwards and pulls the lock of the winch, which does not allow movement of the handle of the winch, so that pulling activation ropes of the winch does not result in activation, as the rope basically cannot be moved. Upon pulling the rope for activation of the winch, the lever of the winch moves downwards, thus pressing the second vertical handle upwards and moving the lock of the splitter. Consequently, activation of the actuator of the log splitter is disabled due to the handle of the splitter being prevented from movement. Movements are enabled by suitable mountings, which are clear to the skilled person, wherein the shape and the dimensions of levers, handles and vertical handles depend on the dimension of other components and their placement in the log splitter and the winch.
Preferably, the first vertical handle for operation as a log splitter is connected with at least one handle of the log splitter via an intermediate lever, which connects the handle of the log splitter with the lever of the log splitter, so that upon movement of the handle of the log splitter, the intermediate lever moves upwards, consequently the lever of the log splitter is moved upwards, which moves the first vertical handle, which with a suitable mounting of the lock for locking the winch moves the lock into a position for blocking movement of the winch lever.
Also preferably, the second vertical handle for the winch operation mode is connected to the winch lever through an intermediate movable part, the lever moving downwards upon pulling the activation rope, which results in the upwards movement of the second vertical handle. With a suitable mounting of the lock of the log splitter on the second vertical handle, said lock is moved in such a manner that the lever of the splitter and thus the handle of the splitter cannot be moved.
Additionally, the said mechanical winch of the log splitter is equipped with a safety switch for turning off winding of the rope onto the drum as described in Slovenian patent application no. P-201900122 , wherein said safety switch is designed so that the end part of the pulling rope is arranged for interaction with a movable part on the housing of the pulling rope guide or above the sheave, on which the rope runs towards the drum. Onto the movable part a Bowden is attached in such a way that upon contact of the end part on the rope with the said movable part the Bowden is moved towards the handle of the clutch. Because the second end of the Bowden is attached on a part of the clutch handle, said movement causes the clutch handle to move into idle, as a retaining element is released. The restraining element keeps the clutch in function during winding of the rope, wherein it is released upon movement of the Bowden. The end part of the pulling rope can push on the movable part directly or indirectly via a mechanical intermediate part and a pushing element. The mechanical stop switch thus preferably comprises:

the movable part installed on a housing of a guide of a pulling rope, which is wound on the drum of the winch,
the Bowden cable, which connects the said movable part with a clutch, wherein the Bowden is connected with the movable part so that the latter may move the Bowden;
the wire rope, which runs inside the Bowden cable, and is attached to the housing of the rope guide;
the clutch with a restraining element for ensuring connection with the drum drive;
the release element, which is on one side attached to the Bowden and on the other side to the clutch near the restraining element, so that it may release the restraining element and thus dislocates the clutch from the drum drive;

Said mechanical winch is also equipped with a brake for proportional release. Namely, when winding is stopped, the drum brake is activated, thus preventing the drum from rotating, wherein the rope is not wound anymore. Following this, the pulled load can be partially or completely released using a brake handle, wherein the said brake handle is through the Bowden, inside which the wire rope is installed, and the lever system connected with the brake belt of the drum, so that the brake handle can affect the status of the brake belt, which can be partially released. In case the brake handle is pulled into its extreme position, the brake of the drum is completely deactivated, the lever system is locked and the rope is freely unwound. During operation of the brake for proportional release the cardan shaft or the sprocket with the chain for transfer of torque, respectively, is still rotating (idle state). Said brake for proportional release elongates the life span of winch parts, as well as more safe and precise work.
In the scope of the invention as defined herein and in the claims other embodiments of the log splitter with the mechanical winch and the safety mechanism for locking the mode of operation clear to the skilled person are possible, which does not limit the essence of the invention as described herein and defined in the claims.
The log splitter with the mechanical winch and the safety mechanism for switching between operation as a log splitter and operation as a winch will be described in further detail based on an exemplary embodiments and figures, which show:

Figure 1: The safety mechanism of the log splitter with the mechanical winch
Figure 2: The upper part of the log splitter with the mechanical winch, safety mechanism for locking the mode of operation, the brake handle for proportional release and the switch for terminating winding of the rope onto the winch drum
Figure 3: The brake for proportional release on the drum of the mechanical winch of the log splitter
Figure 4: The brake for proportional release on the drum of the mechanical winch of the log splitter from the other side

Figure 1 shows an exemplary embodiment of the safety mechanism for the log splitter with the mechanical winch, wherein the safety mechanism comprises:

the first vertical handle 1 for choosing operation as a log splitter, wherein the first vertical handle 1 is:
- ∘ on one side (end) connected to at least one handle 2 of the log splitter via an intermediate lever 3, which connects the handle of the log splitter with the lever 4 of the log splitter, so that upon movement of the handle 2 of the log splitter the intermediate lever 3 is moved upwards, consequently the lever 4 of the log splitter moves upwards, which moves the first vertical handle 1, and
- ∘ on the other side (end) the first vertical handle 1 is with a suitable mounting 1a connected to a lock 5 of the winch, said lock having a shape arranged to stop movement of a lever 6 upon movement of the handle of the log splitter, which disables operation as a winch, as the rope 7 for pulling installed with pulleys 7a cannot be pulled; and
a second vertical handle 8 for choosing operation as a winch, wherein the second vertical handle 8 is:
- ∘ on one end connected with an intermediate movable part 9 onto the lever 6 of the winch, which is arranged to move downwards upon pulling of the rope 7 for activation of pulling, wherein the second vertical handle 8 moves upwards, wherein the winch lever 6 is through the second part of the lever 6a connected with the drum of the winch;
- ∘ on the other end the second vertical handle 8 is connected to the lock 10 of the log splitter, which has a shape arranged to stop movement of the lever 4 of the log splitter, which connects at least one handle 2 with the actuator of the log splitter, thereby disabling operation in the log splitting mode, as the handle 2 of the log splitter cannot be moved, and wherein with a suitable mounting 8a of the lock 10 on the second vertical handle 8 the lock 10 of the log splitter is moved, so that movement of the lever 4 and consequently the handle 2 is prevented.

Due to clarity of the figure, the rope 7 is shown in the figure in a folded state and not during use.
The described safety mechanism showed in figure 1 functions as follows: upon movement of the handle of the log splitter, the first vertical handle moves upwards and pulls the lock of the winch, which enables movement of the winch lever, so that upon pulling the rope for activation of the winch nothing happens, as the rope cannot move. Upon pulling the activation rope the winch lever moves downwards, which pushes the second vertical handle upwards and moves the lock of the lock splitter, so that activation of the log splitter actuator via the handle of the log splitter is prevented, as the said handle cannot move due to the winch lever being moved upwards. Movements are enabled by suitable mountings, which are clear to the skilled person, wherein the shape and the dimensions of levers, handles and vertical handles depend on the dimension of other components and their placement in the log splitter and the winch.
The upper part of the log splitter with the mechanical winch and the safety mechanism is shown in figure 2, which also shows the switch for stopping winding of the rope installed on a sprocket of the winch, via which the rope is led towards the drum of the winch. The said switch 11 comprises:

a movable part 11b installed on a sheave 11a guiding a pulling rope, which is wound on the drum of the winch inside the drum housing 13,
a Bowden cable 11c, which connects the said movable part 11b with a clutch, wherein the Bowden 11c is connected with the movable part 11b so that the latter may move the Bowden;
a wire rope 11d, which runs inside the Bowden cable 11c, and is attached to the movable part 11b and leg 11e on the drum housing connected with the clutch, the connection of the clutch with the drum drive retains a restraining element;
a clutch with a restraining element for ensuring connection with the drum drive;
a release element, which is on one side attached to the Bowden and on the other side to the clutch near the restraining element, so that it may release the restraining element and thus dislocates the clutch from the drum drive;

movable part

Bowden

In addition, the mechanical winch of the log splitter may be equipped with a brake for proportional release, which is shown in figures 2, 3 and 4. Namely, when pulling with the winch is terminated, the pulled load can be step-wise released using the brake handle, wherein the brake handle is connected with the drum of the winch, so that with the position is locked with the handle, the drum can freely rotate (idle state). The brake for proportional release comprises at least:

brake handle 12 for triggering partial release of the brake belt of the drum brake inside the drum housing 13;
said brake handle 12 is through a Bowden 12b, inside which a wire rope 12a is installed, connected to a lever system 12c, so that the wire rope 12a is on one end mounted on the brake handle 12 in a fixed manner, and the handle 12 is on the second end mounted onto the said lever system 12c,
the lever system 12c is connected to the brake belt for braking the winch drum, so that upon pulling of the brake handle 12 a spring is partially released, said spring retaining the brake or the brake belt, respectively, so that the rope is partially unwound and the load is partially released.

In case the brake handle is pulled into its extreme position, the brake of the drum is completely deactivated, the lever system is locked and the rope is freely unwound. During operation of the brake for proportional release the cardan shaft or the sprocket 13a with the chain for transfer of torque, respectively, is still rotating (idle state).

Claims

A log splitter with a mechanical winch for pulling logs, parts of logs or wood towards the log splitter, wherein said log splitter comprises activation handles (2) mechanically connected to an actuator arranged to trigger movement of an axe for splitting logs, and wherein the mechanical winch comprises:
- housing of the winch, in which the drum for winding a pulling rope is installed together with a clutch, a sprocket with a chain and a brake,

- a rope (7) for activation of pulling with the winch, said rope (7) being connected with the clutch of the drum via pulleys, and

- a guide of the pulling rope installed on the said housing, and

- the pulling rope with an end part, which is preferably equipped with forceps for gripping a log or a part of a log,
characterized in that
the log splitter with the mechanical winch is further provided with a safety mechanism arranged to allow choice of operation either of the log spitter or of the winch, wherein the safety mechanism is designed as a system of handles and levers and comprises at least:
- a first vertical handle (1) for choosing operation of the log splitter, wherein the first vertical handle (1) is on one side connected to at least one activation handle (2) of the log splitter and is on the other side connected with a lock (5) of the winch, said lock (5) having a shape arranged to prevent movement of a winch lever (6) upon movement of the activation handle (2) of the log splitter, thus preventing pulling of the activation rope (7); and

- a second vertical handle (8) for choosing operation of the winch, wherein the second vertical handle (8) is on one side connected to the winch lever (6) arranged to move upon pulling the activation rope (7) and is on the other side connected to the lock (10) of the log splitter, said lock (10) having a shape arranged to disable movement of the activation handle (2).
The log splitter according to claim 1, characterized in that:
- the first vertical handle (8) is connected with at least one handle (2) of the log splitter via an intermediate lever (3), which connects the handle (2) of the log splitter with a lever (4) of the log splitter, so that upon movement of the handle (2) of the log splitter, the intermediate lever (3) and the lever (4) of the log splitter are arranged to move upwards, and the first vertical handle (1) is arranged to move the lock (5) of the winch through a suitable mounting (1a) into a position for blocking movement of the winch lever (6) and preventing pulling of the activation rope (7); and

- the second vertical handle (8) is connected to the winch lever (6) through an intermediate movable part (9), wherein upon pulling the activation rope (7) the winch lever (6) is arranged to move downwards and the second vertical handle (8) is arranged to move upwards, wherein with a suitable mounting (8a) of the lock (10) of the log splitter on the second vertical handle (8) is arranged to move the lock (10) in such a manner to prevent movement of the lever (4) and the handle (2) of the log splitter.
The log splitter according to any of the preceding claims, characterized in that the mechanical winch of the splitter is equipped with a safety switch (11) for terminating winding of the rope onto the drum.
The log splitter according to the preceding claim, characterized in that mechanical switch (11) for terminating winding of the rope onto the drum comprises:
- a movable part (11b) installed on a sheave (11a) guiding the pulling rope or on a housing of the guide of the pulling rope, which is arranged to be wound on the drum (13) of the winch, said movable part (11b) being arranged to interact with an end part of the pulling rope, wherein the end part of the rope can push the movable part:
o directly, or

o indirectly via a mechanical intermediate part and a pushing element;

- a Bowden cable (11c), which connects the said movable part (11b) with the clutch, wherein the Bowden (11c) is connected with the movable part (11b) so that the latter may move the Bowden (11c);

- a wire rope, which runs inside the Bowden cable (11c), and is attached to the housing of the rope guide;

- a clutch with a restraining element for ensuring connection with the drum drive;

- a release element, which is on one side attached to the Bowden (11c) and on the other side to the clutch near the restraining element, so that it may release the restraining element and thus dislocate the clutch from the drum drive;
wherein the movable part (11b) upon interaction with the end part of the rope is arranged to move the Bowden (11c) and consequently to move the release element so that the clutch is allowed to move into idle, thus immediately terminating winding.
The log splitter according to any of the preceding claims, characterized in that the mechanical winch is equipped with a brake for proportional release.
The log splitter according to the preceding claim, characterized in that a handle (12) of the brake for proportional release is through a second Bowden (12b), inside which the wire rope (12a) is installed, and an additional lever system (12c) connected to a brake belt of the drum, which is arranged to be partially released upon pulling of the handle (12) of the brake for proportional release.
The log splitter according to the preceding claim, characterized in that the brake for proportional release comprises at least:
- the brake handle (12) for triggering a partial release of the brake belt of the drum brake;

- said brake handle is through the Bowden (12b), inside which the wire rope (12a) is installed, connected to the additional lever system (12c), so that the wire rope (12a) is on one end mounted on the brake handle (12) in a fixed manner, and on the other end mounted onto the said additional lever system (12c),

- the additional lever system (12c) is connected to the brake belt for braking the winch drum, so that upon pulling of the brake handle a spring for retaining the brake or the brake belt, respectively, is arranged to be partially released, thus allowing partial release of a load,
wherein in case the brake handle (12) has an extreme position, in which the brake of the drum is arranged to be completely deactivated and the lever system (12c) is locked, thus allowing free unwinding of the pulling rope.
An operation method of the log splitter with the mechanical winch and the safety mechanism for locking the mode of operation according to any of the preceding claims, wherein the said method comprises the following steps:
- upon movement of the handle (2) of the log splitter, the first vertical handle (1) is moved upwards and the lock (5) of the winch is pulled, said lock (5) having a shape preventing movement of the winch lever (6), thus preventing pulling of the activation rope (7); and

- upon pulling the activation rope (7) the winch lever (6) moves downwards, which pushes the second vertical handle (8) upwards and moves the lock (10) of the log splitter, so that movement of the activation handle (2) of the log splitter is prevented.