GB2590893A

GB2590893A - A log lifter

Info

Publication number: GB2590893A
Application number: GB1915917.7A
Authority: GB
Inventors: Martin Andrew
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-11-01
Filing date: 2019-11-01
Publication date: 2021-07-14
Also published as: GB201915917D0

Abstract

A log lifter 1 comprises jaw assemblies 4 that extend around and grip onto a log. Curved body pivot sections 5 forming contact surfaces configured so that the curved bodies can roll along the ground for the length of the contact 5 surface between a first position where contact with the ground is at the inner end of the curved body, to a second position where contact with the ground is at the outer end. A handle assembly connecting the jaw assemblies 4 and the pivot sections 5 is included and manipulation of the handle section 3 rotates the pivot sections between the first and second positions. Pivot sections 5 and the jaw assemblies 4 are configured so that rolling from the first position to the second position causes a log gripped by the gripping jaw assemblies 4 to be raised off the ground, the pivot sections 5 spaced apart from one another. Jaws 4 may be hooked 4b and comprise a plurality of inner teeth 9 and handle section 3 may comprise telescopic section which are lockable in position relative to one another.

Description

A log lifter

FIELD

The present invention relates to a log lifter. More particularly, the present invention relates to a log lifter with two spaced-apart jacks connected by a brace to allow an 5 entire log to be lifted completely clear of the floor.

BACKGROUND

Log lifers or log jacks are a well-known logging tool that is used to lift large or heavy logs from the ground to allow them to be cut completely through with a chainsaw, so as to divide a long log into shorter and more manageable lengths. A log lifter or log jack generally comprises a long lever handle having a gripping jaw or lever at the lower end on the front side of the lever handle, the jaw configured to extend around a log body in use to trap the log body between the lower end of the lever handle and the gripping jaw. A pivot section on the lower rear side of the lever handle contacts the ground and acts as a fulcrum when the top of the lever is pulled backwards, so that the log held i the jaw will be lifted off the floor at the point at which it is gripped.

A log lifter only acts on one section or part of a log -the part that is gripped. For short logs or short sections, the entire log can be lifted off the floor, as long as the lifter is positioned roughly centrally. However, for longer logs, it is inevitable that one end of the log (that end at the end of the longer section from the lifter to the end) will remain in contact with the floor, or that the lifted log will tip so that that end re-contacts the floor.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

SUMMARY

It is an object of the present invention to provide a log lifter which goes some way to 30 overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

The term "comprising" as used in this specification and indicative independent claims means "consisting at least in part of". When interpreting each statement in this specification and indicative independent claims that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner.

As used herein the term "and/or" means "and" or "or", or both.

As used herein "(s)" following a noun means the plural and/or singular forms of the noun.

Accordingly, in a first aspect the present invention may broadly be said to consist in a log lifter, comprising: at least one gripping jaw assembly configured to extend at least partly around and over the top of a log and to grip onto the log in use; two or more pivot sections, each comprising a curved body that forms a contact surface configured so that the curved body can roll along the ground for the length of the contact surface from a first position where contact with the ground is at or towards the inner end of the curved body, and a second position where contact with the ground is at or towards the outer end of the curved body; a handle assembly configured to connect the at least one gripping jaw assembly and the pivot sections, and further configured so that a user can manipulate the handle section to rotate the pivot sections between the first and second positions; the pivot sections and the gripping jaw assembly or assemblies configured so that rolling of the log lifter on the pivot sections from the first position to the second position causes a log gripped by the gripping jaw assembly or assemblies to be raised off the ground; the pivot sections spaced apart from one another. This allows a log gripped by the log lifter to be fully and stably lifted off the ground.

In an embodiment, the gripping jaw assembly comprises a clamping portion configured to connect to the handle assembly, and a jaw portion that extends forwards from the handle assembly, the clamping portion and handle assembly configured so that the clamping portion can slide freely relative to the handle assembly when the clamping portion is positioned to grip onto a log in use. This allows the position of the gripping jaw assembly to self-adjust In an embodiment, the clamping portion and handle assembly are further configured 30 so that the clamping portion will be held in position on the handle assembly when the log lifter is rolled from the first position. This allows the log to be firmly and securely held In an embodiment, the clamping portion comprises a sleeve configured to fit loosely around the handle portion. This provides a simple and effective mechanism for both sliding and clamping.

In an embodiment, the jaw portion comprises an inwardly-curved and hooked lower 5 end. This helps to prevent the log from moving out of the jaw.

In an embodiment, the jaw portion further comprises a plurality of teeth formed on the inner side of the jaw portion. This helps to prevent the log from moving out of the jaw.

In an embodiment, the jaw portion further comprises a hand aperture formed through the body of the jaw portion. This allows a user to lift and position the jaw portion In an embodiment, each pivot section comprises a wide body configured to distribute the weight over the surface area of the wide body and to assist in the prevention of sinking into soft ground in use. This helps to prevent the log lifter from sinking in soft ground.

In an embodiment, the handle assembly comprises one or more long lever handles, 15 each of the at least one gripping jaw assemblies connected to one of the long lever handles towards the lower end thereof. The handle or handles allow a user to easily manipulate the log lifter.

In an embodiment, a portion of the handle extends below the connection with the gripping jaw assembly, the log lifter further comprising at least one handle tooth connected to and extending forwards from that portion of the handle extending below the connection with the gripping jaw assembly. The tooth helps to prevent rolling of a log along the handle.

In an embodiment, the log lifter further comprises two handle teeth, one of the handle teeth connected to and extending forwards from a point at or towards the lower end of that portion of the handle extending below the connection with the gripping jaw assembly, the other connected to and extending forwards from a point proximate to the connection with the gripping jaw assembly. The teeth help to prevent rolling of a log along the handle.

In an embodiment, each of the long lever handles comprises two or more telescoping 30 sections, lockable in position relative to one another. This allows the length of the handle to be adjusted as required.

With respect to the above description then, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

BRIEF DESCRIPTION OF THE FIGURES

Further aspects of the invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings which show an embodiment of the device by way of example, and in which: Figure 1 shows a perspective view to the front and one side of a log lifter according to an embodiment of the invention, the log lifter comprising a pair of lifting bodies connected via a connecting rod, each lifting body comprising a long lever handle, a gripping jaw configured to grip a log in use, and a pivot section configured to allow the log lifter to be pivoted backwards and upwards to lift the log clear of the floor.

Figure 2 shows a perspective view from the rear and to one side of the log lifter of figure 1.

Figure 3 shows a side view of a log, and the log lifter of figures 1 and 2 being brought up behind the log.

Figure 4 shows a side view of the log and log lifter of figure 3 from the same angle, 30 the gripping jaw opened and positioned on top of the log to grip the log.

Figure 5 shows a side view of the log and log lifter of figures 3 and 4 from the same angle, the handle of the log lifter pushed forwards to engage the gripping jaw with the log.

Figure 6 shows a side view of the log and log lifter of figures 3 to 5 from the same angle, the gripping jaw fully engaged with and gripping the log, the handle of the log lifter pulled rearwards onto the pivot section to raise the log and log lifter.

Figure 7 shows the handle pulled fully rearwards so that the upper end rests on the 5 floor, the lower end of the log lifter raised on the pivot section so that the log is held off the floor.

DETAILED DESCRIPTION

Embodiments of the invention, and variations thereof, will now be described in detail with reference to the figures In an embodiment, the log lifter 1 comprises a pair of lifting bodies 2, connected via a connecting rod 12. Each lifting body 2 comprises a long lever handle 3, a gripping jaw 4, and a pivot section 5.

In this embodiment, the long lever handle 3 is formed from two metal tubes 3a, 3b, formed from steel or another suitable material. The tubes 3a, 3b are configured so that the upper tube 3b slides within the lower tube 3a, so that the tubes connect to one another telescopically. This allows the overall length of the long lever handle 3 to be adjusted as required. The tubes can be locked in position relative to one another. In this embodiment, tube 3b is locked to tube 3a using a spring button lock 6. A pair of teeth 11 extend forwards from the front of tube 3a, one at the lower end of the tube, and the other a short distance above this, below the point at which the gripping jaw 4 connects with the lever handle 3, as outlined below.

The gripping jaw 4 comprises a connection portion 4a that removably clamps to the lever handle 3 (tube 3a) via a sleeve 8 that fits over the top of the tube 3a, and a grip or jaw portion 4b that is rotatably connected to the connection portion 4a, the axis of rotation formed/positioned so that the jaw 4b pivots directly backwards and forwards relative to the lever handle 3.

The gripping jaw 4 can be moved up and down the lower length of the lever handle 3 via the sleeve 8, and locked in the required position via a locking mechanism 7. The locking mechanism 7 can comprise any suitable mechanism, but the preferred mechanism is the same or similar to that described and shown in GB2520055. That is, the sleeve 8 can freely move up and down the tube 3a when held at a certain angle, and is a loose fit around the tube 3a, but under ifs own weight it is naturally biased away from alignment with the tube 3a, and is biased towards being at an angle to the tube 3a, so that unless the sleeve 8 held at the angle at which it can freely move, the sleeve 8 will rotate under it's own weight relative to the tube 3a, and the inner sides of the sleeve 8 will contact and press against the surface of the tube 3a so as to hold the sleeve 8 in position on the tube 3a. The weight of the attached jaw portion 4b will also tend to pull or rotate the front of the sleeve 8 downwards, which increases this effect.

The jaw portion 4b comprises a solid curved metal jaw that curves inwardly towards the handle 3. The upper end is rotationally connected to the connection portion 4a as outlined above. The opposite/lower end is hooked inwards (towards the direction of the curve) and ends in a sharp point. Teeth 9 are formed on the inner side of the jaw portion 4b, across the 'top' of the curve. A hand-sized and -shaped aperture 10 is formed through the upper side of the jaw portion 4b, to allow a user to grip the jaw portion 4a and rotate this in use, around and away from a log.

The pivot section 5 comprises a wide, curved section of metal material 5a that is connected to, and which extends from, the rear of the handle 3. An inner end of the material extends over and connects with the lower end of the handle 3, the body of the metal material curving out and around the lower rear of the handle 3 in the opposite direction from the curve of the jaw portion 4b, the outer end of the material 5a connected to and spaced away from the handle 3 via a spacer/connector 5b. The lower or outer surface of the metal material 5a forms a contact surface, and when the log lifter 1 is in use, it will roll along the floor or ground surface, with part of the contact surface in contact with the ground as it rolls, and forming a contact patch. The width of the pivot section helps to distribute the weight of the log lifter 1 and it log load over a wider surface area, which helps to prevent the log lifter sinking into soft ground in use.

In this embodiment, two substantially identical lifting bodies 2 are connected side-byside and spaced apart via a connecting rod 12, that has connecting sleeves 13 at each end. The tube connecting sleeves 13 are slipped over the top of the handles 3 (the tube sections 3b) and are held in place at the required location via friction screws 14 at the front of the sleeves 13.

In use, the log lifter 1 is positioned at the rear of a log to be lifted, as shown in figure 3. The jaw portions 4b are rotated so that the 'mouth' (formed between the jaw portion 4b and the lower end of the handle 3) is fully open, and the log lifter 1 is moved forwards to contact the log as shown in figure 4.

The jaw portions 4b are dropped to rotate downwards so that they contact the top of 35 the log, and the log lifter 1 is pushed up against the log and the top of the handle 3 rotated forwards so that the log is held or trapped within the mouth -that is, gripped between the jaw portions 4b and the lower end of the handle 3 -with the teeth 11 extending forwards and biting into the rear of the log, as shown in figure 5. In this position, the inner end of the curved section of metal material 5a is in contact with the ground. During this process, the weight of the jaw portion 4b is held by the log, as the jaw portion 4b is resting on top of the log. This, plus the rotation of the jaw portion 4b to an open position, puts the collar 8 in a position where the collar 8 is not angled so as to grip onto the tube 3a, and so the collar 8 can slide along the tube 3a. This allows the gripping jaw 4 to slide along the tube 3a to the optimal location -the position of the jaw portion 4 automatically adjusts to the size of the log held between the jaw portion 4b and the lower end of the tube 3a.

A user then grasps the handle or handles 3, and/or the connecting rod 12, and pulls this/these rearwards, as shown in figure 6. This causes the log lifter to rotate or pivot rearwards on the wide, curved section of metal material 5a. As the handle or handles 3 are pulled backwards, the change of angle causes the orientation of the collar 8 to change relative to the handle 3, and the collar 'grips' back onto the handle 3.

The handles can be pulled fully rearwards until the upper end of the handles contacts the floor, as shown in figure 7. At this point, the outer end of the wide, curved section of metal material 5a will be in contact with the floor. In this position, the full length of the log is lifted clear of the floor to a short height (the height of the teeth 11, the width of the handle 3, and the spacer/connector 5b), and is held stably and securely in this position. The teeth 11 ensure that the log cannot roll along the handle 3 in this rearwardly-sloped position.

In this position, as the pivot sections are spaced apart along the length of the log sufficient distance to prevent the weight and leverage of the log from tipping the log lifter 1 to one side or the other to rest on one of it's ends, a user can perform operations on the log as required without having to be concerned about contact with the floor. For example, a user can cut the log into shorter lengths with a chainsaw, without being concerned that the teeth of the chain will contact the floor, and be blunted or that the chain will break.

In the embodiment described above, two substantially identical lifting bodies are described, connected via a connecting rod. It is possible for three or more lifting bodies to be connected in a similar manner in a line or series, by using a connecting 35 rod adapted or formed so as to be suitable for connection of three or more lifting bodies in a line. It is also possible to use lifting bodies without handles or with shorter individual handles, with the two or more lifting bodies connected via a handle assembly that connects the lifting bodies On this embodiment formed from the gripping jaw, the pivot section, and the lower part of the handle 3a, below the collar 8 with only a short extension above), with a single central handle, or multiple handles but not one handle for each lifting body.

Claims

Claims 1. A log lifter, comprising: at least one gripping jaw assembly configured to extend at least partly around and over the top of a log and to grip onto the log in use; two or more pivot sections, each comprising a curved body that forms a contact surface configured so that the curved body can roll along the ground for the length of the contact surface from a first position where contact with the ground is at or towards the inner end of the curved body, and a second position where contact with the ground is at or towards the outer end of the curved body; a handle assembly configured to connect the at least one gripping jaw assembly and the pivot sections, and further configured so that a user can manipulate the handle section to rotate the pivot sections between the first and second positions; the pivot sections and the gripping jaw assembly or assemblies configured so that rolling of the log lifter on the pivot sections from the first position to the second 15 position causes a log gripped by the gripping jaw assembly or assemblies to be raised off the ground; the pivot sections spaced apart from one another.
2. A log lifter as claimed in claim 1 wherein the gripping jaw assembly comprises a clamping portion configured to connect to the handle assembly, and a jaw portion that extends forwards from the handle assembly, the clamping portion and handle assembly configured so that the clamping portion can slide freely relative to the handle assembly when the clamping portion is positioned to grip onto a log in use.
3. A log lifter as claimed in claim 2 wherein the clamping portion and handle assembly are further configured so that the clamping portion will be held in position 25 on the handle assembly when the log lifter is rolled from the first position.
4. A log lifter as claimed in claim 2 or claim 3 wherein the clamping portion comprises a sleeve configured to fit loosely around the handle portion.
5. A log lifter as claimed in any one of claims 2 to 4 wherein the jaw portion comprises an inwardly-curved and hooked lower end.
6. A log lifter as claimed in any one of claims 2 to 5 wherein the jaw portion further comprises a plurality of teeth formed on the inner side of the jaw portion.
7. A log lifter as claimed in any one of claims 2 to 6 wherein the jaw portion further comprises a hand aperture formed through the body of the jaw portion.
8. A log lifter as claimed in any one of claims 1 to 7 wherein each pivot section comprises a wide body configured to distribute the weight over the surface area of 5 the wide body and to assist in the prevention of sinking into soft ground in use.
9. A log lifter as claimed in any one of claims 1 to 8 wherein the handle assembly comprises one or more long lever handles, each of the at least one gripping jaw assemblies connected to one of the long lever handles towards the lower end thereof.
10. A log lifter as claimed in claim 9 wherein a portion of the handle extends below the connection with the gripping jaw assembly, the log lifter further comprising at least one handle tooth connected to and extending forwards from that portion of the handle extending below the connection with the gripping jaw assembly.
11. A log lifter as claimed in claim 10 further comprising two handle teeth, one of the handle teeth connected to and extending forwards from a point at or towards the lower end of that portion of the handle extending below the connection with the gripping jaw assembly, the other connected to and extending forwards from a point proximate to the connection with the gripping jaw assembly.
12. A log lifter as claimed in any one of claims 9 to 11 wherein each of the long lever 20 handles comprises two or more telescoping sections, lockable in position relative to one another.