DE29511337U1 - Drawbar for power-driven industrial trucks - Google Patents

Description

PATENT ATTORNEYS _# ·.·..· *..* &iacgr;

DR.-ING. H. NEGENDANK (-1973)

HAUCK, GRAALFS, WEHNERT, DÖRING, SIEMONS
K-39067-19 HAMBURG - MUNICH - DÜSSELDORF

PATENT AND LAWYER ■ NEUER WALL 41 · 20354 HAMBURG

Jungheinrich AG Friedrich-Ebert-Damm 129

2 2047 Hamburg

EDO GRAALFS, Dipl.-Ing. NORBERT SIEMONS, Dr.-Ing. HEIDI REICHERT, Attorney-at-Law Neuer Wall 41, 20354 Hamburg Telephone (040) 36 67 55, Fax (040) 36 40 Telex 2 11 769inpatd

HANS HAUCK, Dipl.-Ing. WERNER WEHNERT, Dipl.-Ing. Mozartstraße 23, 80336 Munich Telephone (089) 53 92 36, Fax (089) 53 12

WOLFGANG DÖRING, Dr.-Ing. Mörikestraße 18, 40474 Düsseldorf Telephone (0211) 45 07 85, Fax (0211) 454 32 Telex 8 584 044 dopa d

DELIVERY ADDRESS/PLEASE REPLYTO:

HAMBURG,

July 12, 1995

Drawbar for power-driven industrial trucks

The invention relates to a drawbar for power-driven industrial trucks according to the generic term of latent. Saying 1.

Pallet trucks or loaders in walk-along mode have a drawbar with which the conveyor is steered. The drawbar is connected to the bracket for the swiveling drive wheel of the conveyor. A drawbar head is provided at the free end, which has several actuating elements for operating the conveyor. The latter include a drive switch, buttons for raising and lowering, the horn and a body protection switch.

Patent attorneys · European Patent Office, · Authorized representatives in the European Patent Office

Attorney: admitted to German courts

Deutsche Bank AG Hamburg, No. 05 28497 (ÖLZ ibt) 700*00) '"PbsrtAnk HaiHburg No. 28 42 206 (BLZ 200 100 20)
Dresdner Bank AG Hamburg, No. 933 60 35 (bank code 200 800 00)

It is known to provide the drawbar head with a horn as an extension of the drawbar shaft, to which handles are attached on both sides. The operating switches are mounted on the horn. From EP 0 371 227 or EP 0 371 226 it is known to connect the handles to a protective bar, which is made up of support sections extending transversely from the horn on both sides and of leg sections running approximately parallel to the horn. The handles are connected to the leg sections, which create handle openings on both sides of the horn. Between the handle and the horn, control switch handles are arranged on both sides, which can be rotated with the thumb around an axis that approximately coincides with the axis of the handles. The switch buttons for raising and lowering operations are housed in the section of the horn that protrudes to the rear beyond the handles.

From the company brochure Atlet electric tiller pallet truck (LL) it has become known that in a part of the horn facing the driver in the area of the carrying sections, two opposite switch buttons are provided for operating the lifting and lowering operation. The switch buttons are operated with the fingertip by exerting pressure by stretching out the fingers (opening the hand on the handle).

From the company brochure ROCLA-ELEKTRO-GEH-GABELHUBWAGEN RHE-14 it is known to attach a desk-like flat inclined surface to the support sections that connect the leg sections with the horn, in which switch buttons for the lifting and lowering operation as well as the horn are arranged on both sides of the horn.

The invention is based on the object of creating a drawbar for power-driven industrial trucks in which the drawbar head is designed in such a way that all operating functions can be operated clearly and effortlessly with one hand. In addition, it should be possible to operate several operating functions simultaneously with just one hand without the operator's hand having to be released from the drawbar handle.

This problem is solved by the features of claim 1.

In the drawbar head according to the invention, the switch buttons are arranged in a row next to each other in a surface that slopes down from the horn to the side in such a way that they can be activated by extending a finger of a hand grasping the handle in the direction of the natural gripping movement of the finger.

Preferably, three control buttons are arranged on each side of the horn, whereby the control buttons are preferably rectangular buttons that protrude only slightly from the surface immediately adjacent to one another. Such a design of the drawbar head not only enables particularly ergonomic operation of the control buttons during normal operation, but also "blind" operation with one hand at a time, i.e. even when the operator turns away from the drawbar and walks ahead of the vehicle.

According to one embodiment of the invention, the surface containing the switch buttons is formed by a recess that extends between a leg section and the associated control switch handle. The recess has a slope both to the side, i.e. away from the horn, and an incline towards the operator. This enables the row of switch buttons to be arranged for ergonomically sensible operation in the manner according to the invention. Above all, the invention enables ergonomic operation of the buttons without having to let go of the handle.

According to one embodiment of the invention, the switching buttons are preferably located on the preferably straight edge of the

Recess that limits the handle opening in this area. The row of switch buttons is not parallel to the handle, but rather arranged at an angle, with the rows of switch buttons on both sides of the horn enclosing an angle such that they diverge away from the handles.

According to another embodiment of the invention, the upper section of the horn is raised above the plane formed by the handle and the leg section, so that the switch button closest to the horn is located slightly above the handle.

According to a further embodiment of the invention, the support sections are rounded in cross-section, which is known per se. However, according to the invention, the support sections taper towards the leg section. This results in a curved course of the support sections in the area of the handle openings, which therefore narrow towards the horn. On the outside, the support sections are arched, thus forming a repelling and deflecting surface when hitting an obstacle. In cross-section, this area is also rounded.

The leg sections are also designed towards the handle opening.

preferably with a rounded cross-section, but according to one embodiment of the invention have a flattened area on the outside. This allows the overall width of the drawbar head to be reduced.

According to another embodiment of the invention, the handles run on a curved line, the center of the circle on the side facing the drawbar handle. Furthermore, according to another embodiment of the invention, the plane of the handle and leg section can be inclined downwards away from the handle, which accommodates the natural hand position in the working position of the drawbar.

According to another embodiment of the invention, the top and the side of the control switch handle facing away from the driver have a resting surface for the index finger of the hand holding the handle. The resting surface is curved in the direction of rotation of the control switch handle. As a result, the control switch forms a continuation of the handle in the direction of the drawbar horn. The handle opening can therefore be moved further in the direction of the horn, which means that the width of the drawbar head can be reduced. In order to obtain an obstacle-free transition between the handle and the resting surface, this is designed with a slope in the direction of the handle.

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In addition, the grip surface can be concave in cross-section to allow a better adaptation to the index finger.

The control switch handle has a thumb recess on the side facing the driver, so that it can be operated while the hand is gripping the handle. This feature is known per se. According to the invention, the upper base section of the thumb recess is narrower than the lower one. This makes it easier to operate the control switch handle, especially when the driver turns away from the tiller head. During this movement, the thumb is automatically moved further away from the control switch handle, even if the hand is still gripping the handle. Because the lower area of the handle recess is wider, it is still possible to operate it ergonomically using the thumb.

According to a further embodiment of the invention, the drawbar head according to the invention preferably consists of two parts with a lower part and an upper part, whereby the division takes place in a plane of the horn running from the front to the rear end. The lower part is designed as a supporting part and has the handles, the leg sections and the supporting parts of the supporting sections.

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The lower part also has the supporting section of the horn. The upper part is designed as a shell to cover part of the supporting sections and the horn and has the trough-like surfaces that accommodate the key arrangement. The lower and upper parts can be connected to one another by a simple screw fastening.

An embodiment of the invention is explained in more detail below with reference to drawings.

Fig. 1 shows a perspective side view of a drawbar head according to the invention.

Fig. 2 shows the view of the drawbar head according to Fig. 1 in the direction of arrow 2.

Fig. 3 shows the view of the drawbar head according to Fig. 1 in the direction of arrow 3.

Fig. 4 shows a perspective view of a control handle of the drawbar head according to Figures 1 to 3.

Fig. 5 shows the side view of the handle according to Fig. 4
Fig. 6 shows the view of the handle according to Fig. 5 in the direction

direction arrow 6 ·

Fig. 7 shows the top view of the lower part of the drawbar head according to Figures 1 to 3.

Fig. 8 shows the top view of the upper part of the drawbar head according to Figures 1 to 3.

The drawbar head 10 shown in Figures 1 to 3 belongs to the drawbar (not shown) of a lifting truck or the like (not shown). The drawbar is indicated by the end of its handle 12. As can be seen, there is an upward bend at 14 at the end of the handle. The handle-side section 16 of the drawbar head, which is approximately rectangular in cross-section and is connected to the handle 12 in a suitable manner, also extends in this direction.

The drawbar head 10 has a horn 18 in the extension of the handle-side section 16, which is approximately rectangular in plan view, but has a hump shape upwards in side view, as indicated by the contour line 20. On the underside, the horn is concave in side view, as indicated by the contour line 22. This creates

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the horn 18 in the rear part facing the operator maintains an orientation that is approximately parallel to the axis of the stem 12.

A box-shaped switch button 24 is provided, which encompasses the sides of the free end of the horn 18 but is received by the horn at the top and bottom and operates a body protection switch. The button 24 is mounted in such a way (not shown) that contact from a variety of directions leads to a switch being operated.

At the transition section between the handle-side section 16 and the horn 18, support sections 26, 28 are provided, which extend laterally from the horn 18 and taper outwards. The support sections are arched and concave in the direction of the drawbar 12, as shown at 30 and 32, respectively, and in this area have an approximately circular contour in cross-section. They also merge into the horn 18 and section 16 via soft transition surfaces and curves. At the ends of the support sections 26, 28, leg sections 34, 36 are connected, which extend approximately parallel to the horn 18 in the direction of the operator side and are connected to rod-like handles 38, 40. The leg sections 34, 36 are on the side facing the horn

The cross-section of the ribs is approximately circular on the side facing &Igr;&dgr;, while they are flattened on the outside, as indicated at 42, 44 in Figures 2 and 3.

The handles 38, 40, which lie on a circular arc line whose circle center is on the side of the stem 12, extend in the direction of the horn 18 to the control switch handles 46, 48, which are mounted so as to be rotatable about a horizontal axis about an axis perpendicular to the horn on the vertically running outside of the horn. The axis of rotation corresponds approximately to the axis of the handles 38, 40 near the handles 46, 48. The shape of the control switch handles 46, 48 is discussed in more detail below.

It can be seen that the described parts create grip openings 50, 52 for the fingers of a hand that grasps the handle 38 or 40 from behind and diagonally above. The grip openings 50, 52 have the greatest width in the plane of the leg sections 34, 36 and handles 38, 40 approximately in the longitudinal center of the support section 26, 28 or handle 38, 40, whereby they gradually narrow in an arc shape towards the horn 18 and towards the leg sections 34, 36. The arc shape results from the curvature of the handles 38, 40 and the corresponding concave curvature

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of the support sections, as indicated by the contour lines 54, 56. A further curvature results from the contour line 58 or 60 of the control switch handle 46 or 48 in the area of an index finger support surface 6 2 or 64 (the latter will be discussed in more detail below).

Troughs 66, 68 are formed in the support sections 26, 28. They extend at the base of the horn 18 and from its top along the support sections 26, 28 in the direction of the leg sections 34, 36. As can be seen in Fig. 1, the troughs 66, 68 have a slope in the direction of the leg sections 34, 36. They also have a slope in the direction of the handles 38, 40. Adjacent to the handle openings 50, 52, the troughs 66, 68 have an approximately straight edge 70 or 72, which delimits an essentially rectangular recess 74, 78 to the handle opening 50 or 52. In the recess 70, 72, three switch buttons 80, 82 are arranged in a row next to one another. As can be seen from Fig. 1 and 3, the course of the row of switch buttons 80 and 82 is approximately adapted to the course of the trough base, and the switch buttons 80, 82 protrude only slightly over the base of the trough 66 and 68. The row of switch buttons 80, 82 therefore follows the gradient in the direction of the leg sections 34, 36. The switch buttons

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80, 82 lie on a circular arc whose centre lies outside the recess 66, 68, with the axes of the keys 80, 82 intersecting approximately in the centre.

From Figures 2 and 3 it can be seen that the rows of switch buttons 80, 82 form an angle to each other such that they diverge away from the handles 38, 40 or converge towards the handles 38, 40.

From Fig. 1 it is clear that the leg sections 34, 36 and the handles 38, 40 lie in a plane that approximately coincides with the axis of the handle end section 14 and encloses an angle to the axis of the handle 12, which is directed downwards, by an amount of approximately 20°. The angle encloses the handles 38, 40 is approximately 160°.

As already indicated, the drive switch handles 46, 48 both operate a switch for controlling the travel speed of the conveyor (not shown). The switch buttons 80, 82 are used for raising and lowering and for sounding the horn, whereby, as can be seen, the functions on both sides of the head 10 are redundant. Of course, it is also possible to operate one side of the tiller head "blindly".

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The horn is preferably operated by the outermost switch button 80 or 82.

The travel switch 48 is shown enlarged in Figures 4 to 6. It has a disk-shaped section 84 on one side, which faces the corresponding flat surface on the side of the horn 18. Towards the rear, towards the operator, a recessed grip 86 is formed, which is delimited by approximately radially projecting sections 88 and 90. The projections 88, 90 enclose an angle of approximately 70 to 80°. When a handle 40 is grasped, the corresponding thumb of the hand reaches the recessed grip 86 and can therefore operate the handle 48 in both directions of rotation. As can be seen from Figures 4 and 6, the axial extension of the projection 90 is significantly larger than that of the upper projection 88, so that the bottom of the recess 86 gradually narrows from the lower projection 90 to the upper projection 88. On the side opposite the disk section 84, the handle body 48 has a spherical recess 92 into which the spherical end of the handles 38, 40 (see also Fig. 7) protrudes, but at a distance. The lower edge of the recess 92 has a recess 94 on the one hand, through which the assembly of the handle body 48 is made possible. A bore 91 serves to accommodate a bearing pin.

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In the direction away from the operator, the projection 88 is adjoined by a flat surface 96, which is followed by an index finger rest recess 98. An inclined surface 100 extends from the upper flat surface 96 in the direction of the recess 92 corresponding to the widening of the base of the thumb recess 86.

As can be seen from Fig. 5, the finger recess 98 extends approximately over 180° of the handle body 48. It is slightly concave in cross-section and slopes continuously from the height of the disk section 84 in the direction of the recess 92. The finger rest surface 98 (position 62, 64 in Fig. 2 and 3) is shaped in such a way that when a handle, for example handle 40, is grasped by one hand, the index finger can rest on the surface 98 in a more or less curved manner. The support surface 98 therefore forms an extension of the handle 40 in the direction of the horn 18. Overall, the support surface 98 is shaped in such a way that it forms a continuation of the contour of the handle 40, as can be seen from Figures 1 to 3.

The contours of the drawbar handle shown in Figures 1 to 3 are such that when a handle 38, 40 is grasped by one hand, the switch buttons 80 and 82 are

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can be easily operated with one finger in a gripping position without letting go of the handle 38 or 40. By operating the thumb, the drive switch handle 46 or 48 can be operated simultaneously in one or the other direction of rotation. Operating the drive switch handle 46, 48 is ergonomically optimal even when the operator turns away from the drawbar.

The drawbar head according to Figures 1 to 3 consists of two parts, namely a lower part 104 and an upper part 106, which will be described in more detail below with reference to Figures 7 and 8. Where parts shown in Figures 1 to 3 are shown, the same reference numerals are used.

As can be seen from Figures 7 and 8, the lower part 104 is designed as a supporting part with the horn lower part 18', the molded support section lower parts 26', 28', the leg sections 34, 36 and the handles 38, 40. The horn lower part 18' widens in a triangular shape towards the support sections 26', 28' in order to ensure a stable connection and the corresponding accommodation of switches (not shown) that can be actuated by the switch buttons 80 and 82, respectively.

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On the other side of the support section lower parts 26', 28', a fastening projection 108 is formed, with which the drawbar head can be fastened to the handle 12 of the drawbar, which is otherwise not shown. As can be seen from Fig. 7, a fastening bush 110 or 112 is formed on the projection 108 and on the drawbar head lower part for a fastening screw (not shown).

The drawbar head lower part 104 shown in Fig. 7 can be manufactured entirely from plastic in one piece.

The upper part 106 can be seen in Fig. 8. It is shaped like a bowl and covers the extension 108 and the lower part 18' of the horn. These parts are designated 18'' and 108'' in Fig. 8. It also covers the lower parts of the support section 26', 28'. The corresponding sections are designated 26'' and 28'' in Fig. 8. The lower part 104 and the upper part 106 are pivoted together.

The upper part 106 can also be molded in one piece from plastic.

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Claims (22)

Expectations : 1. Drawbar for power-driven industrial trucks, with a drawbar handle, a drawbar head arranged at the free end of the drawbar handle, consisting of a horn arranged as an extension of the drawbar handle, rod-like handles extending approximately transversely to the horn on both sides of the horn, which are connected to the horn or the handle via leg sections attached to the outer ends of the handles and extending approximately parallel to the horn and via support sections connected to the leg sections, the legs and support sections forming a protective bar with handle openings, a drive switch handle between the handle and the horn, which is mounted on the horn so as to be pivotable approximately around the axis of the handle, at least two switch buttons on each side of the horn, which are arranged in surfaces of the support sections which slope diagonally towards the vertical in such a way that they can be operated with the fingers, characterized in that the switch buttons (80, 82) are arranged in a row next to one another on a surface (66, 68) sloping from the horn (18) to the side so that they can be pulled out by extending a finger of a handle (38, .../19 19 - 40) grasping hand in the direction of the natural grasping movement from the fingertip. 2. Drawbar according to claim 1, characterized in that rectangular buttons (80, 82) are provided which protrude slightly from the surface (66, 68) immediately adjacent to one another. 3. Drawbar according to claim 1 or 2, characterized in that three switch buttons (80, 82) are arranged on each side of the horn (18). 4. Drawbar according to one of claims 1 to 3, characterized in that the surfaces are formed by a trough (66, 68) extending between the travel switch handle (86, 88) and the leg section (34, 36). 5. Drawbar according to claim 4, characterized in that the approximately straight trough edge (70, 72) facing the handle (38, 40) simultaneously delimits the handle opening (50, 52) on the side of the support section (26, 28) and the switch buttons (80, 82) are arranged close to the trough edge (70, 72). 6. Drawbar according to one of claims 1 to 5, characterized . . ./20 characterized in that the rows of switching buttons (80, 82) are arranged at an obtuse angle on both sides of the horn (18) such that they converge in the direction of the handles (38, 40). 7. Drawbar according to one of claims 1 to 6, characterized in that the axes of the switch buttons converge upwards on one side of the horn (18), preferably at a point which corresponds to the center of the circle on which the button lies or which the recess describes. 8. Drawbar according to one of claims 1 to 7, characterized in that the upper section (20) of the horn (18) is raised above the plane formed by the handle (38, 40) and leg sections (34, 36) and the switch button (80, 82) closest to the horn (18) is approximately adjacent to the upper side (20) of the horn (18), 9. Drawbar according to one of claims 1 to 8, characterized in that the support sections (26, 28) are formed as extensions of the horn (18) which are rounded in cross section and which taper continuously away from the horn (18). 10. Drawbar according to claim 9, characterized in that the support sections (26, 28) on the side opposite the handle opening (50, 52) are convexly curved and have an approximately circular cross-section. 11. Drawbar according to one of claims 1 to 9, characterized in that the leg sections (34, 36) have a rounded cross-section towards the handle opening (50, 52) which has a flattened area (42, 44) on the outside. 12. Drawbar according to one of claims 1 to 11, characterized in that the support sections (26, 28) have a rounded cross-section towards the handle opening (50, 52). 13. Drawbar according to one of claims 1 to 12, characterized in that the outer sections of the support sections (26, 28) are arranged at an obtuse angle to one another so that they diverge in the direction of the handles (38, 40). 14. Drawbar according to one of claims 1 to 13, characterized in that the handles (38, 40) run on a curved line, the center of the circle of which lies on the side facing the handle (12). . . ./22 - 22 - 15. Drawbar according to one of claims 1 to 14, characterized in that the plane of the handle (38, 40) and leg section (34, 36) is inclined downwards away from the handle (38, 40) in the working position of the handle (12). 16. Drawbar according to one of claims 1 to 15, characterized in that the top side and the side of the control switch handle (46, 48) facing away from the operator have a support surface (98) curved in the direction of rotation of the control switch handle for the index finger of the hand grasping the handle (38, 40). 17. Drawbar according to claim 16, characterized in that the support surface (98) forms an extension of the handle (38, 40) rising towards the horn (18). 18. Drawbar according to one of claims 1 to 17, characterized in that the drive switch handle (46, 48) has a thumb recess (86) on the side facing the operator, the upwardly facing bottom wall section of which is narrower than the downwardly facing bottom section and the lateral boundary of the drive switch handle (46, 48) in the region of the narrow bottom wall section is formed by an inclined surface (100). is formed with a slope towards the handle (38, 40) . 19. Drawbar according to one of claims 1 to 17, characterized in that the free end of the handle (38, 40) is hemispherical and projects into an approximately hemispherical recess of the drive switch handle (46, 48). 20. Drawbar according to one of claims 1 to 19, characterized in that a section of the horn (18) projects rearward over the travel switch handles (46, 48) and a switch cap (24) for a body protection switch is inserted into the front side of the projecting section. 21. Drawbar according to one of claims 1 to 20, characterized in that the drawbar head (10) is composed of an upper and lower part (106, 104) that can be connected via screw connections, the lower part (104) having the handles (38, 40), the leg sections (34, 36), supporting parts (26', 28') of the support sections (26, 28) and the supporting part (18') of the horn (18) and the shell-like upper part (106) forming the upper side of the horn (18) and a .../24 Part (26'', 28'') of the support sections (26, 28) including the surface (66, 68) supporting the switch buttons (80, 82). 22. Drawbar according to one of claims 1 to 21, characterized in that the switches actuated by the switching buttons (80, 82) are proportional switches. . . ./25