WO1998053379A1

WO1998053379A1 - Ergonomically shaped lever for initiating movements in mobile or stationary vehicles

Info

Publication number: WO1998053379A1
Application number: PCT/SE1998/000969
Authority: WO
Inventors: Hans Gustafsson
Original assignee: Parker Hannifin Ab
Priority date: 1997-05-20
Filing date: 1998-05-20
Publication date: 1998-11-26
Also published as: AU7561998A; SE510776C2; EP0983538A1; SE9701883L; SE9701883D0

Abstract

An ergonomically shaped lever for initiating movements in mobile or stationary vehicles. The lever comprises a handle (70) which has a substantially asymmetric cylindrical shape about a longitudinal axis (100), to correspond to the gripping of a hand and a switch (60) having one or more switching points. The switch further has at least one part (40) which protrudes from the handle (70), which is arranged in the longitidudinal direction to the handle, to manually be switched by a hand or a finger. The protruding part (40) projects so that, when a hand and/or a finger performs a movement parallel to the longitudinal direction of the handle, a force is produced which is directed inwards towards the longitudinal axis (100) of the handle.

Description

TITLE

Ergonomically designed lever intended for initiating movements in moving or stationary vehicles.

TECHNICAL FIELD

The present invention relates to an ergonomically designed lever intended for initiating movements in moving or stationary vehicles according to Patent Claim 1.

STATE OF THE ART

It is generally known to use levers for initiating movements in moving or stationary vehicles. These vehicles may be, for example, forest machinery, cranes, excavators, trucks and the like, which are usually provided with a lever. This lever may, for example, be intended for manoeuvring a lifting arrangement, for example a crane, which may be provided with gripping claws, a scoop or the like. There are also vehicles in which other functions can be performed using the lever, such as forward, backward and swivel. The lever is usually of cylindrical design and can be rocked in one or more directions. It is also usual to provide the lever with one or more change-over switch (es) . Such a change-over switch may, for example, initiate a backward or forward movement of the vehicle and/or of the crane. During protracted working using a machine provided with such a lever, it is common for certain strain injuries and cramp to occur, for example in joints and in muscles (primarily in hands and/or arms) , which are often caused by static movements on account of the design of the lever. This may also lead to the driver becoming less attentive which in turn may contribute to highly dangerous accidents. One way of possibly reducing the occurrence of strain injuries and cramp is described in EP-A2- 0,712,062. This makes use of an ergonomically designed handle which can be gripped comfortably by the hand of the driver and in this way avoids strain in the wrist . The handle may be designed in such a manner that the flat of the hand rests on the upper part of the handle, and the thumb rests against one side of the handle that lies at right angles to the upper part of the handle. The handle is also provided with at least one change-over switch located on the side of the handle that lies at right angles to the upper part of the handle, and is mounted movably in at least one plane. Furthermore, the handle is intended for controlling primarily the forks on a truck, the handle being mounted on a rigid shaft, that is to say manoeuvring takes place only by means of the change-over switch.

However, the change-over switch that is described in EP-A2-0, 712, 062 is designed so that the grip of the driver has to be changed when this change-over switch is to be used, that is to say while the driver presses on the change-over switch so as to perform one function, he must change grip in order to perform a second function. The reason for this is that the change-over switch is of the two-way type. Furthermore, the force from the finger that is pressing on the change-over switch is of such a nature that the finger moves in the direction away from the flat of the hand, which feels more strenuous than moving the finger in the direction towards the flat of the hand instead.

DESCRIPTION OF THE INVENTION One object of the present invention is therefore to provide an ergonomically designed lever intended for initiating movements in moving or stationary vehicles, which is less strenuous for joints and muscles in, for example, arms, wrists and hands than known levers. According to the present invention, this object is achieved by providing an ergonomically designed lever according to Patent Claim 1.

Preferred embodiments of the method and the arrangement according to the invention are indicated in detail in the respective subclaims.

DESCRIPTION OF THE FIGURES

The invention will emerge in greater detail from the description below of a preferred embodiment shown by way of example with reference to the appended drawings, in which:

Fig. 1 shows a lever according to the present invention, and Fig. 2 shows a preferred method of use for a lever according to the invention.

PREFERRED EMBODIMENTS

Figure l shows an ergonomically designed lever intended for initiating movements in moving or stationary vehicles. The lever includes a handle 70 which has essentially an asymmetrical cylindrical shape around a longitudinal axis 100 in order to be suitable for being held by a hand, and a change-over switch 60 with one or more change-over points. The length of the essentially cylindrical handle may be, for example, around 60 to 80 mm, preferably roughly 70 mm, while the radius may be around 30 to 50 mm, preferably roughly 40 mm. The longitudinal axis 100 may be considered to be an imaginary line which passes through the centre of the handle 70. The change-over switch is also provided with at least one part 40 which projects from said handle and is intended to be manually changed over by a hand or finger. The lever may be provided with a shaft (not shown) which is arranged movably in a plane by means of a joint (not shown) arranged between the handle 70 and the shaf .

The projecting part 40 projects to such an extent that, when a hand and/or a finger performs a movement parallel to the longitudinal direction of the handle, an inwardly directed force can be brought about towards the longitudinal axis 100 of the handle. By virtue of the fact that the hand and/or finger can be directed towards the axis 100, the movement of the hand and/or the finger will therefore be directed towards the flat of the hand, which feels less strenuous than if the movement were directed away from the flat of the hand.

The change-over switch 60 may be arranged in the longitudinal direction of the handle 70, for example vertically, so that the projecting part 40 follows the longitudinal direction of the handle. It is of course possible to arrange the change-over switch horizontally instead of vertically, depending on the design of the lever. For example, the lever may be designed in such a manner that the flat of the hand lies facing the ground, the body or in between. The exemplary embodiment shown in Figure 1 is primarily intended so that it is possible for a hand to take a grip in which the flat of the hand is directed in towards the body when the arm is straight and parallel to the body.

Furthermore, the projecting part 40 may comprise a surface that is angled in relation to the longitudinal direction of the handle 70, at an angle of between 40 and 80°, preferably between 50 and 70°, and most preferably around 60°. This contributes to making it possible for, for example, a thumb to be supported on this surface. Moreover, the change-over switch can be pressed in using a smaller force than otherwise required if the surface is at right angles in relation to the longitudinal direction of the handle 70.

The upper part 10 of said handle may be of dish- shaped design in order for a finger to be accommodated therein, which may be, for example, an index finger or a thumb. If suitable, other fingers and even the whole hand may of course be used. The reason why it may be most suitable to use the thumb or the index finger is that a greater force can be applied using these fingers, in particular in the case of a forward movement. This is because a greater surface area of the flat of the hand can be accommodated on the handle when these fingers are used, at the same time as the remaining fingers do not have to be turned in a manner that feels unnatural. It is therefore to be preferred that use is made of the index finger or the thumb so as to achieve the desired effect, that is to say to avoid injury to muscles and joints. The dish-shaped recess that is formed in the upper part may start from a radius of around 10 to 30 mm, preferably roughly 20 mm. The upper part 10 may be of essentially circular design with a radius of around 40 to 60 mm, preferably roughly 50 mm. In a similar manner to the upper part 10, the handle may be provided with a dish-shaped recess 20 in the longitudinal direction, on the side opposite the change-over switch, in order for at least one finger, preferably three fingers, to be accommodated therein. Two fingers or more than three fingers may of course be accommodated in the recess 20, if the user should prefer this. The fingers that it is suitable to accommodate in this recess 20 are a middle finger, a ring finger and either a little finger or an index finger or both. If these fingers are used, a firm and comfortable grip can be achieved. Moreover, this recess will facilitate a movement in the lateral direction, during a forward or backward movement also, as a greater surface area of the flat of the hand can be accommodated on the handle when these fingers are used, at the same time as the remaining fingers do not have to be turned in a manner that feels unnatural. In this way, it is possible to avoid injuries in muscles and joints. This dish-shaped recess may be designed starting from a radius of around 20 to 40 mm, preferably roughly 30 mm.

Figure 2 shows a preferred method of using a lever according to the invention, in which the recess 20 in the longitudinal direction, preferably in the vertical direction, accommodates three fingers, the index finger is placed on the upper part 10 and the thumb on the change-over switch 60. In this way, a comfortable grip can be achieved and the lever can be manoeuvred without it being strenuous for joints and muscles.

It is possible to consider using various plastics and/or rubber as materials for manufacturing a handle. A further advantageous embodiment may be to use a soft rubber material (or plastic) so as to bring about a surface that is moulded according to the contours of the hand so that the grip feels soft and comfortable. If the base for the handle comprises a thermosetting plastic, for example fibreglass, which is subsequently to be coated with a soft rubber material, it is usual to employ two different moulds in this procedure . It would therefore also be advantageous to spray-coat directly onto the thermosetting plastic as this represents a saving in terms of both material {at least one mould) and work operations in a manufacturing procedure.

Furthermore, the change-over switch 60 may be provided with a second projecting part 50 so as to achieve the same hand-grip when the number of change-over points is more than one. This second projecting part may project around 4 to 12 mm, preferably 6 to 10 mm, most preferably 8 mm. The change-over switch 60 may, in a similar manner to the first projecting part 40, be arranged in the longitudinal direction of the handle 70 so that the projecting part 40 follows the longitudinal direction of the handle. The parts 40, 50 may be of asymmetrical design. The first projecting part 40 may be located below the second projecting part 50 so that the first projecting part 40 projects further than the second part 50. The first may project X mm further than the second, where X may have a value from close to zero up to around 5 mm, preferably roughly 4 mm, and most preferably roughly 3.5 mm. This means that the first part may project around 4.0 to 15.5 mm, preferably around 6.0 to

13.5 mm, most preferably 11.5 mm. That part of the handle

70 where the first projecting part 40 is located may be

-provided with a recess so as to be capable of receiving and also extending an inward movement by a finger. This recess may be formed, for example, starting from a radius of around 3 to 9 mm, preferably roughly 6 mm. A similar recess may be provided on the handle where the second projecting part 50 is located, and this recess may be formed, for example, starting from a radius of around 6.0 to 12.0 mm, preferably roughly 9 mm, and most preferably roughly 8.8 mm. Furthermore, the second projecting part 50 may comprise a surface that is angled in relation to the longitudinal direction of the handle 70, at an angle of between 35 and 75°, preferably between 45 and 65°, and most preferably around 55°.

Furthermore, the change-over switch may be mounted on a spindle (not shown) which allows the projecting parts 40, 50 to perform a circular movement around this spindle. The change-over switch may be provided with springs which are arranged so that the projecting parts may be imparted a spring-back movement when, for example, a change-over has taken place. Although the embodiments shown of the present invention have been described in detail with reference to the accompanying figures, it is to be understood that the invention is not limited to these specific embodiments and that various alterations or modifications may be effected by an expert without departing from the scope or the underlying idea of the invention.

Claims

PATENT CLAIMS

1. Ergonomically designed lever intended for initiating movements in moving or stationary vehicles, which includes a handle (70) which has essentially an asymmetrical cylindrical shape around a longitudinal axis (100) in order to be suitable for being held by a hand, and a change-over switch (60) with one or more change- over points which is provided with at least one first part (40) which projects from said handle (70) , where said first projecting part (40) is arranged in the longitudinal direction of said handle and is intended to be manually changed over by a hand or finger, characterized in that said projecting part (40) projects to such an extent that, when a hand and/or a finger performs a movement parallel to the longitudinal direction of the handle, an inwardly directed force is brought about towards the longitudinal axis (100) of the handle.

2. A lever according to Patent Claim 1 , characterized in that a surface on said projecting part (40) is angled in relation to the longitudinal direction of the handle (70), at an angle of between 40 and 80┬░, preferably between 50 and 70┬░, and most preferably around 60┬░.

3. A lever according to Patent Claim 1 or 2 , characterized in that said lever is provided with a shaft which is arranged movably in a plane by means of a joint arranged between said handle (70) and said shaft.

4. A lever according to Patent Claim 1, 2 or 3, characterized in that the upper part (10) of said handle is of dish-shaped design in order for a finger to be accommodated therein.

5. A lever according to Patent Claim 4, characterized in that said upper part (10) is designed so as to accommodate an index finger or a thumb.

6. A lever according to any one of the preceding - 9 - patent claims, characterized in that the longitudinal direction of said handle (70) is provided with a dish- shaped recess (20) in order for at least one finger, preferably three fingers, to be accommodated -therein.

7. A lever according to Patent Claim 6, characterized in that said recess (20) is designed to accommodate a middle finger, a ring finger and a little finger or an index finger or both.

8. A lever according to any one of the preceding patent claims, characterized in that said change-over switch (60) is provided with a second projecting part (50) so as to achieve the same hand-grip when the number of change-over points is more than one.

9. A lever according to Patent Claim 8, characterized in that said projecting parts (40, 50) are of asymmetrical design.

10. A lever according to Patent Claim 8 or 9, characterized in that said first projecting part (40) projects further than the second part (50) .

11. A lever according to Patent Claim 8, 9 or 10, characterized in that said first projecting part (40) is arranged below said second part (50) .