HK1046126B - Lifting jack - Google Patents

Description

Hoisting device

Technical Field

The invention relates to a hoisting device. Hoisting devices of the type described are used in particular for vertical displacement of weights. It comprises a drive wheel, often formed as a sprocket wheel, which can be rotated in both directions by means of a manually operable endless chain. But instead of a sprocket a gear wheel may be used. The drive wheel can then be formed as a clutch wheel for a motor shaft.

The load wheels, which are usually likewise designed as chain wheels, are connected to the support device, for example a crane hook, by means of a link chain.

The housing of the lifting device is usually provided with a hook, by means of which it can be hung on a suitable support.

In the housing, in an axial sequence, a drive wheel, a load pressure brake, a load wheel and a gearbox are arranged, wherein the gearbox is often designed as a planetary gearbox. The drive wheel is mounted on the end of a drive shaft which passes through the load pressure brake and the load wheel. A gearbox is located at the other end of the drive shaft and then the gearbox is connected to the load wheel for torque transfer.

Background

In one known construction of the lifting device described above (a sample of the Yale industrial products ltd., 5620 Velbert 1 "Yale flashchenzug/Hand Hoist/palaan a bras mod.vs") the load pressure brake consists of a ratchet wheel, two friction discs on either side of the ratchet wheel and two pawls hinged to the housing. The pawl is pressed on the ratchet wheel under the action of the belleville spring. The two friction disks are connected in a friction-locking manner with the ratchet wheel on the one hand and with a pressure disk or drive wheel fixed on the shaft on the other hand. The drive wheel is axially displaceable on one end of the drive shaft by means of a screw thread. The other end of the drive shaft is connected to two toothed wheels, which are themselves connected to a toothed wheel with internal toothing via a pinion of smaller diameter, into which a pinion connected to the load wheel is inserted.

The load pressure brake has the task of maintaining the load carried by the lifting device at the current height when the driving wheels are stationary. The drive wheel is then pressed against the pressure plate via the friction disk and the ratchet wheel, the pawls being located in circumferential tooth spaces of the ratchet wheel.

If the drive wheel rotates in the lifting direction, the ratchet wheel slides over the teeth of the ratchet wheel until the drive wheel is stationary. The pawl then snaps back into the gullet of the ratchet wheel. When the weight is lowered, the drive wheel rotates in the opposite direction, thereby causing it to slide axially on the moving thread of the drive shaft and terminating in frictional locking contact with the friction, ratchet and hold-down discs. The weight can be lowered until the shaft following the rotation compensates for the axial play again.

In the known design, the disadvantage that the load pressure brake can fail when foreign bodies enter or the helical spring breaks has proven to be worthwhile to improve. Pawl noise is undesirable in many applications, particularly where such noise results in a noise incident. Secondly, the production of the load pressure brake is expensive, wherein in particular the machining of the ratchet wheel should be provided.

Disclosure of Invention

Starting from the prior art, the object of the invention is to create a lifting device which is easy to produce, insensitive to faults and low in noise.

The solution according to the invention for this object is characterized in that the drive wheel is mounted on the drive shaft so as to be axially immovable but with limited relative rotation and in that it can rotate with a brake wheel which is axially movable on a threaded section of the drive shaft and which, with the interposition of a friction disk, can press against a pressure plate fixed to the housing as part of a load pressure brake.

According to this feature the drive wheel is axially immovable, although it is limited in its relative rotation with respect to the drive shaft. The drive wheel is furthermore connected in a rotationally limited manner to a brake wheel which is itself axially displaceable on a threaded section of the drive shaft. A friction disk is arranged between the brake wheel and a pressure disk fixed on the housing of the lifting device.

If it is desired to lift the weight, the drive wheel is rotated clockwise. After a defined angle of rotation, at which the drive wheel can rotate freely relative to the drive shaft, the free rotational movement is ended. The drive shaft is driven directly by the hand wheel, and the brake is not stressed. The braking action is eliminated because the threaded section is designed such that the brake wheel disengages the friction disc when the right-hand thread is rotated clockwise.

If the rotational movement of the drive wheel is stopped, the drive shaft rotating under the weight pulls the brake wheel towards the friction disc and thus also towards the pressure disc, and the weight is locked.

The drive wheel must be rotated counterclockwise in order for the weight to drop. After the wheel rotates by a specified angle, the driving wheel is connected with the brake wheel. Because the right-handed threaded segment brake wheel is axially displaced on the threaded segment in the direction of the drive wheel, contact between the friction disc and the compression disc is eliminated. The weight can then follow the prescribed angle of rotation between the drive wheel and the brake wheel and can thereafter be braked again by the drive shaft rotating under the influence of the weight pulling the brake wheel toward the friction disk and the friction disk toward the pressure disk.

A particular advantage of the invention is that it operates more accurately and with much less noise than known types of construction. The lifting device according to the invention is also simpler in terms of the number of components.

Secondly, it can be concluded that the drive shaft and thus also the load wheel are driven directly by the drive wheel, while the load pressure brake is not subjected to force.

The drive wheel may be driven by a chain, rope, crank, as in the prior art, or by means of a motor.

The rotatability of the drive wheel on the drive shaft is preferably achieved by means of a sleeve which is fixed on the drive shaft. The sleeve may be press fit over the drive shaft.

The drive wheel interacts with an impeller which is connected to the drive shaft in a rotationally fixed manner. For this purpose, the drive wheel has an end-face projection which, after a defined rotation angle of the drive wheel, comes into contact with the impeller with its respective stop, so that the impeller and the drive shaft are rotated.

The sleeve is also positioned on the drive shaft by means of an impeller which is non-rotatably mounted on the drive shaft.

The impeller is preferably mounted on a serration spline on the end of the drive shaft and pressed against the sleeve by a nut, the sleeve itself being pressed against the shoulder of the drive shaft by a radial shoulder. The drive wheel is then precisely actuated between this radial shoulder and the end face of the impeller facing it. The impeller has at least one radially projecting vane which interacts with at least one end-face-directed projection on the drive wheel. The free rotation of the drive wheel on the drive shaft is limited by the interaction of the projections and the blades. The weight can thus be lifted by the drive wheel. The impeller preferably has two radial blades which are offset by 180 ° with respect to one another. Then preferably two are also provided on the end face of the drive wheel. In particular integrally cast projections, which interact with the blade.

The connection of the drive wheel and the brake wheel with limited rotational movement is preferably achieved by the feature that the brake wheel is provided with an axially arranged driving pin at a radial distance from the drive shaft. The driving pin engages in a fan-shaped recess, which is curved in particular in an arc, on the side of the drive wheel facing the load wheel. The ends of the recesses into which the driver pins are inserted are then formed by radially arranged ribs. The driving wheel drives the brake wheel to lift the brake wheel from the pressing disk when the heavy object descends, and the load pressure brake is released.

In a further development of the invention, the brake wheel is pressed against the pressure plate by a spring mounted on the drive wheel. The main task of the spring is to generate an initial braking torque. The response time of the load pressure brake can thereby be shortened.

Drawings

The invention will be explained in more detail below with the aid of an embodiment shown in the drawing.

In the drawings:

FIG. 1 is a top plan view of the lifting device;

FIG. 2 is a vertical longitudinal section through line II-II of the view of FIG. 1;

FIG. 3 is a vertical cross-sectional view through line III-III of the view of FIG. 1;

fig. 4 is a front view of the view of fig. 1 with the cover removed in the direction of arrow IV.

In fig. 1 to 4, a lifting device is indicated by 1, for example for lifting or lowering a weight L.

Detailed Description

The lifting device 1 has a drive wheel 2, a load pressure brake 3, a load wheel 4 and a gear housing 5 arranged in an axial sequence in a housing G, not illustrated in detail. The drive wheel 2 is arranged at one end 6 of a drive shaft 7 and can be connected for torque transmission via the drive shaft 7 through the load pressure brake 3 and the load wheel 4 to a gear box 5 at the other end 8 of the drive shaft 7, which gear box outputs to the load wheel 4.

At the end 6 of the drive wheel 2 in the form of a sprocket wheel for a circular chain, not shown in detail, the drive shaft 7 is provided with a cylindrical length 9 (fig. 2) which merges into a serration 10 on the face side and from the serration 10 into an end thread segment 11. A sleeve 13 with a radial shoulder 12 is placed over the cylindrical length 9 and rests on a shoulder 14 of the drive shaft 7. The sleeve 13 is pressed against the shoulder 14 by means of the impeller 15 and can be pressed against the sleeve 13 and the shoulder 14 by screwing a nut 16 onto the threaded section 11, by means of which the impeller is pressed against the sleeve 13 and the sleeve is pressed against the shoulder 14 (fig. 1, 2 and 4).

The impeller 15 can be seen in fig. 4. It has a central annular body 17 on which two radially projecting blades 18 are arranged offset by 180 °. The vanes 18 each have a circular-arc-shaped curved back region 19 and a stop surface 20 extending in a radial plane. The stop surface 20 of the blade 18 is in contact with a projection 21 integrally formed on the exposed side 22 of the drive wheel 2.

The drive wheel 2 has an inner hub 23 with which it slides between the radial shoulder 12 of the sleeve 13 and the facing end face 24 of the impeller 15 (fig. 2).

On the side 25 facing away from the projection 21, the drive wheel has three circular arc-shaped curved sector-shaped recesses 26 (fig. 2 and 3), which are bounded by three radial ribs 27. In one of these recesses 26, a driving pin 28 is inserted, which is fastened to a brake wheel 29 at a radial distance from the drive shaft 7. The brake wheel 29 is axially displaceable on the external thread 31 of the drive shaft 7 adjacent to the cylindrical length 9 by means of the internal thread 30. The internal threads 30 and the external threads 31 are formed as right-hand drive threads.

The brake wheel 29 is formed in the shape of a ring on the side facing away from the drive wheel 2 and is in contact with a friction disk 32, which is itself pressed against a pressure disk 33, which is fastened to a transverse plate 34 (fig. 2) forming part of the housing. The abutment of the brake wheel 29 against the friction disk 32 and the abutment of the friction disk against the pressure plate 33 is supported by a helical compression spring 35 which surrounds an axial projection 36 of the brake wheel 29 and engages in an annular groove 37 of the drive wheel 2.

The transverse plate 34 of the housing G supporting the pressure plate 33 and a further transverse plate 38 arranged parallel to one another at a distance from it serve together for rotatably supporting the load wheel 4 (fig. 1 and 2), which likewise serves as a chain wheel for a round-link chain. The bearings of the load wheel 4 on the transverse plates 34 and 38 are indicated at 39. The load wheel 4 is mounted so as to be rotatable relative to one another on two cylindrical running surfaces 40 of the drive shaft 7, which are spaced apart from one another by an axial distance. It is inserted with an axial socket 41 into a gear 42 which is mounted non-rotatably on this socket 41 beside the upper cross-plate 38.

When viewing fig. 1 and 2, it can be seen that the gear 42 meshes with two pinions 43 which are part of two gears 44, which gears 44 in turn mesh with a gear end section 45 of the drive shaft 7.

Assuming that a weight L should be lifted, the driving wheel 2 rotates clockwise according to arrow PF of fig. 1, 3 and 4. Since the drive wheel 2 is initially free to rotate relative to the drive shaft 7 on the sleeve 13, the drive wheel 2 is moved in a relative rotational movement relative to the drive shaft 7 until the projections 21 come into contact with the blades 18 of the impeller 15. Since the impeller 15 is non-rotatably fixed to the drive shaft 7 by means of the serration 10, the drive shaft 7 now also rotates clockwise according to arrow PF. The torque is thus transmitted from the driving wheel 2 directly to the load wheel 4 via the drive shaft 7 and the gearbox 5. Due to the right-hand drive threads 30, 31 of the brake wheel 29 and of the drive shaft 7, the brake wheel 29 is lifted from the friction disk 32, as shown by arrow PF1 in fig. 2, when the drive wheel rotates clockwise as shown by arrow PF, so that the friction disk is also lifted from the pressure disk 33. The weight L can be lifted without braking.

If the drive wheel 2 stops, the suspended weight L causes the load wheel 4 to rotate in the direction of arrow PF3, i.e. counter clockwise, thereby also rotating the drive shaft 7. The brake wheel 29 is thus pulled in the direction of arrow PF2 towards the friction disc 32 and towards the pressure disc 33. The weight L is fixed at this height (fig. 1-4).

If the weight L should be lowered, the drive wheel 2 is rotated counter-clockwise in the direction of arrow PF3 in fig. 1-4. After a predetermined angle of rotation, the driving pin 28 comes into contact with a rib 27 of the drive wheel 2, so that the brake wheel 29 now also moves on the drive thread 31 of the drive shaft 7 and lifts it off the friction disk 32 and the friction disk 33. The weight L then causes the drive shaft 7 to rotate relative to the drive wheel 2, causing the brake wheel 29 to be drawn again towards the friction discs 32, according to arrow PF2, thereby causing the friction discs to be drawn towards the pressure disc 33 and the weight L to be braked.

List of reference numerals

1 lifting device 2 driving wheel

3 load pressure brake 4 load wheel

5 end of gearbox 67

7 end of drive shaft 87

97 serration splines on cylindrical length 106

116, a radial shoulder of threaded section 1213

13 shaft shoulder on sleeve 147

15 impeller 16 nut

1715 annular body 1815 blades

1918 Back region 20 stop surface

Side of protrusion 222 on 212

232 end face of hub 2415

252 on side 2625

2726 on the rib 2829 driving pin

29 internal thread of brake wheel 3029

317 external thread 32 friction disc

33 pressing disc 34 horizontal plate

35 boss of helical compression spring 3629

372 annular groove 38 transverse plate

Sliding surface on bearing 407 of 394

414 gear of adapter 42

43 pinion 44 gear

Gear segment on 457

G hoisting apparatus's casing L heavy object

PF arrow PF1 arrow

PF2 arrow PF3 arrow

Claims (5)

1. Hoisting device with a drive wheel (2), a load pressure brake (3), a load wheel (4) and a gear box (5) arranged axially in series in a housing, in which the drive wheel (2) arranged at one end (6) of the drive shaft (7) can be connected for torque transmission by means of the drive shaft (7) passing through the load pressure brake (3) and the load wheel (4) to the gear box (5) located at the other end (8) of the drive shaft (7) and outputting to the load wheel (4), characterized in that: the drive wheel (2) is mounted on the drive shaft (7) so as to be axially immovable but with limited relative rotation and can be rotated with a brake wheel (29) which is axially movable on a threaded section (31) of the drive shaft (7) and which, with the interposition of a friction disk (32), can be pressed against a pressure disk (33) fixed to the housing as part of the load pressure brake (3).

2. A lifting device as claimed in claim 1, characterized in that: the drive wheel (2) is rotatably mounted on a sleeve (13) fixed to the drive shaft (7).

3. A lifting device as claimed in claim 1 or 2, characterized in that: the drive wheel (2) has an end-face-side projection (21) which interacts in a torque-transmitting manner with an impeller (15) which is connected to the drive shaft (7) in a rotationally fixed manner.

4. A lifting device as claimed in claim 1 or 2, characterized in that: the brake wheel (29) has an axially arranged driving pin (28) which engages in a sector-shaped recess (26) of the drive wheel (2) on the side (25) facing the load wheel (4) in a relatively displaceable manner.

5. A lifting device as claimed in claim 1 or 2, characterized in that: the brake wheel (29) is pressed against the pressure plate (33) by a spring (35) mounted on the drive wheel.