DE3120235A1 - "THREE-PIECE LIFTING STAND, PREFERRED FOR FORKLIFT" - Google Patents

Description

Three-part lift stand _? preferably for forklifts

The invention relates to a three-part lifting stand, preferably for forklift trucks, according to the preamble of claim 1.

Forklift trucks, which have to work in low spaces , but at the same time should have a large lifting height, can expediently be equipped with a three-part lifting stand, ie with a lifting stand that has three pairs of slide rails. Furthermore, the stand should be designed as a free lifting stand, that is, the fork carriage is first moved to its highest position before the lifting movement of the slide rails begins.

The invention is based on the object of providing a simple embodiment to develop for a three-part lifting stand »

To solve this problem, a three-part lifting stand is proposed according to the preamble of claim 1, which according to the invention has the features mentioned in the characterizing part of claim 1.

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May 18, 1981 20 950 P.

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Advantageous further developments of the invention are set out in the subclaims called.

According to the invention, the actuating cylinder or cylinders are arranged in a novel manner and ropes or chains drawn in a new way for the lifting movement. The use of two laterally arranged cylinders with in opposite = Telescopically extendable piston rods set in directions give a good view through the stand.

The first pair of slide rails is carried by a chassis and is usually articulated to this, to allow pivoting movement. The second pair of slide rails is vertically movable and is guided in the first pair of slide rails. The third pair of slide rails is also vertically movable and is guided in the second pair of slide rails. The fork carriage can be moved vertically and is guided on the third pair of slide rails.

Essential for the invention is the attachment of one or more actuating cylinders for the lifting movement on the second pair of slide rails. If only a single actuating cylinder is used, then this will be with two pistons equipped and with a piston rod that can be extended upwards and one downwards. When using multiple actuation cylinders separate cylinders can be used for the piston rods that can be extended upwards and downwards. Two separate chain or rope systems are used in the lifting

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18.5 ο 1981 20 950 P

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stand used "A first chain or a first cable is _w ith their / its one end fixed on the upper part of the first Gleitschienenpaares. This chain or this rope runs over a pulley on the piston rod _P, which can be extended downwards, from there over a pulley on the upper part of the third pair of slide rails and from there down to the fork carriage a second rope is fastened with her / his - *** ■ one end to the second pair of slide rails ₉ runs from here over a roller on the upwardly extendable piston rod and is fastened with her / its other end to the lower part of the third pair of slide rails,

The invention is to be explained in more detail with the aid of the exemplary embodiment shown in the figures Figure 1 to 3 a three-part lifting stand according to the

Invention in different working positions _{see p}

^ Figures 4 and 5 an actuating cylinder with two piston rods ρ , namely in Figure 4 with retracted piston rods and in Figure 5 with extended piston rods «,

A first pair of slide rails is articulated on a not shown Chassis mounted a second pair of slide rails 2 is guided by the first pair of sliding rails third pair of slide rails 3 is from the second pair of slide rails 2 out, and the fork carriage 4 is on the third

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Pair of sliding rails 3 out. On the second pair of slide rails 2 an actuating cylinder 5 is permanently attached »The actuating cylinder belongs to the type that has two piston rods 6« 7 is equipped, which are extendable in opposite directions to each other. The outer end of each piston rod 6, carries a roller (e.g. pulley or chain wheel) 8 or 9 " At the upper end of the third pair of slide rails is a pulley 10 »A rope or chain 11 is at the top of the first pair of slide rails 1 and attached to the fork carriage 4. It runs over rollers 8 and 10 “A rope or a chain 12 is attached to the second pair of slide rails 2 and to the lower area of the third pair of slide rails 3. This rope or chain runs over the roller 9.

The actuating cylinder. 5 can be designed in the manner shown in FIGS. It consists of a cylinder 13> which is firmly connected to the second pair of slide rails 2. Die.ser cylinder 13 contains a downward extendable Piston rod 6 and a hollow cylindrical piston rod 7 which can be extended upwards. In the retracted state the piston rod 7 is in the piston rod 6. The space 1 / | in the actuating cylinder 5 is via a line 15 to a Pressure medium source connected. When actuated, the force acting on the piston rod 7 is twice as great as that. force acting on the piston rod 6. By making the cross-sectional area of the piston rod 6 slightly larger than half makes the cross-sectional area of the piston rod 7, one can achieve that the fork carriage (load carrier) initially in his

May 18, 1981

- '20 950 p

upper position is raised * before the slide rails ?. and be lifted 3 "Optionally, it may be desirable to provide a locking device ,, _s which locks the Gabeltrnger 4 in its upper position and so it lish ion in this position during the raising and lowering of the sliding holding couple 2 and 3. FIG. When the fork carriage h has been lifted into the upper position shown in FIG extended and lifts the fork carriage together with the slide rail pairs 2 and 3 (see Figure 3) After the Gleitschienenpaare have reached their lower positions _s of the fork carrier is lowered relative to the slide rail pair 3,

The three-part lifting stand according to the invention enables the fork carriage to move during the entire lifting movement moved at a constant stroke speed. The pressure of the pressure medium is essentially during the entire stroke movement constant ρ if the cylinder cross-sectional area of the piston rod 7 is measured in such a way that it is approximately twice as large as the cross-sectional area of the piston rod 6 "

Claims (4)

Patent claims: 1. Three-part lift stand for handling material, preferably for forklift trucks, with a first pair of slide rails (1) which is mounted on a chassis, with a second vertically movable pair of slide rails (2), which is guided by the first pair of slide rails (1) is, with a third vertically movable pair of slide rails (3), which is from the second pair of slide rails (2) is guided, and with a · vertically movable fork carrier (4), which is guided by the third pair of slide rails (3), characterized in that one or more There are actuating cylinders (5) firmly connected to the second pair of slide rails (2), that the cylinder (s) (5) piston rods that can be extended upwards or downwards (6 or » 7) have, which are provided with rollers (8,9) for ropes or chains (10, 12) that a first rope or a first chain (11) is attached to the upper section of the first pair of slide rails (1), from here via a roller (8) runs on the downward extendable piston rod (6), from here a roller (10 ·) runs on the upper section of the third pair of slide rails (3) and from here to the Fork carriage (4) runs to which it is attached and that a second rope or chain (12) on the second Pair of sliding rails (2) is attached, from where it / she via a roller (9) on the piston rod that can be extended upwards (7) runs to the third pair of slide rails (3), 20 950 p at the lower portion of which it / she "is attached. 2. Three-part lifting stand according to claim 1, characterized in that that two separate actuating cylinders (5) are present, each of which one downwards and one afterwards has extendable piston rod (6, 7) at the top. 3. Three-part lifting stand according to claim 1, characterized in that that a single actuating cylinder (5) is present, one of which can be extended downwards and one upwards Has piston rod (6, 7). 4. Three-part lifting stand according to claim 2 or 3, characterized characterized in that the cross-sectional area of the piston rod (7) which can be extended upwards is approximately twice as large is like the cross-sectional area of the downward extendable piston rod (6). / 3