US2173685A

US2173685A - Lifting jack

Info

Publication number: US2173685A
Application number: US251752A
Authority: US
Inventors: Grassmann Erich
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-01-18
Filing date: 1939-01-19
Publication date: 1939-09-19
Anticipated expiration: 1956-09-19

Description

' Sept. 19, 1939.

E. GRASS'MANN LIFTING JACK Filed Jan. 19, 19:59

2 Sheets-Sheet l Sept. 19, 19 39. '5. GRASSMANN 2,173,635

LmIN JACK Filed Jan. 19, 1939 2 Sheets-Sheet 2 Patented Sept. re, 1939 PATENT OFFICE;

LIFTING JACK Erich Grassmann, Gelsenkirchen, Germany Application January 19, 1939, serlagNo. 251,752

In Germany January 18, 1 38 15 Claims. This invention relates to lifting devices or jacks. The lifting device according to the invention comprises a continuous or linked band of metal which can be wound into spiral form, two members, namely a rotor and a stator, disposed concentrically so as to enclose an annular space therebetween, a helically ascending guide track for said band in said annular space, a slot in the outer member of said two concentric members through which said band can pass to said guide track, means for engaging said band with the inner member of said two concentric members and means for rotating the rotor relatively to the stator. The structural height of the device is low and the device is inexpensive to construct, yet it is capable of being used for raising loads to a height of several metres and is therefore particularly suitable for lifting aircraft, motor cars, machinery, buildings, etc. When collapsed, the device occupies only a small space and is therefore particularly adapted for use in military work as by the engineering corps. It can be used as a pressure device or as a supporting device or lifting 'deviceand as a' conduit for gases and liquids which can be easily made tight in places where rigid pipes cannot be employed. The metal or linked band can be provided with one or more rows of projecting pins and perforations along its edges, in such a way that, when it is formed into a tube, the projecting pins-in one convolution of the helix engage in the perforations of the adjacent convolution, so that the helical convolutions are connected together so that they can resist pressure without bending; The stator and rotor can be interchanged as desired, depending upon whether the tube is to rotate while being formed or whether the tube is to be formed without rotating. a

in the centre of a rotatable cylindrical casing, which contains the band wound in the form of a spiral. It is also possible to separate the '09sing which contains the band and the driving means from one another if an eccentric arrangement of the head ofthe lifting device is desired.

The casing which contains the band is preferably mounted on rollers or balls in order to reduce friction when the band is'being extended into tubular form. The helical guide track for the band can consist ,of or be provided with rollers.

In order to form the band into a. cylindrical tube of which the individual convolutions are of conical form and engage one within another, so as to project one above another with overlapping It is advantageous to fit the rotor and stator edges, the edge of the metal band may be curved. Then the radius of the tube formed from the band remains constant and the tube is ableto support pressure without pins and perforations being arranged in the edges of the band.

In order to reduce friction on the helically ascending guide track and to avoid damage to I the edges of the band which carry the load, the rollers of the helical track' can be connected together by straps and a chain constituted by-blocks which arelinked together may be carried by the rollers. The rollers can be of conical shape, the I conicity depending on the radius of the helical guide track. The connecting straps are provided with elongated holes for the purpose of 15 increasing the flexibility.

The blocks forming the chain are preferably bevelled or tapered at the joints in such a way as to be movable in all directions.

In order that the invention may be readily understood and carried into effect, a lifting device constructed in accordance with the invention is illustrated by way of example in the-accompanying drawings, in which:

Figure 1 is a vertical section through the base 25 of the lifting device,

Figure 1a isa horizontal half section on the lines la-la of Figure 1,

Figure 2 is a vertical section through the guide track showing a roller, the chain of blocks and 30 the steel band,

Figure 3 isan elevation showing the rollers and part of the chain and steel band,

Figure 3a is a horizontal section through a part of the chain' of bloc Figure 4 is a part plan of the rollers,

Figure 5 is a side=view of one of the straps by which the rollers are connected, I

Figure 6 is a detail view of another form of band, and

Figure '7 is a perspective view. of the device partly broken away.

Referring to the drawings, the box-like casing I carries at its'centre the cylindrical stator 8 which has longitudinal grooves" 2| in the outer 45 surface. Around the stator is mounted on ball bearings 3 a cylindrical rotor II in the innersurface of which a helical guide track 22 is cut out. Around the rotor H and between ball bearings 4 is mounted a drum a spirally wound metal band 5. (Figure 1.) The rotor H is provided with, an opening 24 (Fig. 1a) for guiding the band ,to the annular space 26 a which is enclosed between the rotor and stator. The band isprovidedlatits lower edge with a 5 25 which carries series of holes 6 and carries at its upper edge a series of pins l (Figure 2). The edge 30 of the band may be of circular curvature as shown at 29 in Figure 6. Qn the guide track.22, which preferably slopes upwards towards the inside (Figs. 1 and 2), are mounted conical rollers In which are connected together by means of straps H. The straps l2 are provided with elongated eyes 20 (Figure 5) for enabling the chain formed to be movable in all directions. The rollers l2 support an endless chainformed of blocks 9 which possess guide slots 23 for the edge of the band 5. In order that the chain may be movable to allsides the bolt holes l9 at the joints are of double conical form, as shown in Figure 3a.

The steel band 5 which passes through said slot 24 in the rotor ll engages by means of its pins 1 in the grooves 2lin the stator 8. When the rotor H is rotated through the agency of the toothed wheels l3, M by turning the spindle l5, the'band is raised by means of the chain of locks 9 carried on the guide track 22 and thus formed into acylindrical tube. Rollers 2 (Figure 1a) press the pins 1 in the convolution 21 into the holes 6 in the convolution 28, so that the cylindrical tube is able to resist axial pressure. The band carries a head plate ll'l having a turntable l8 for raising objects. The rollers l0 and the blocks 9 both of which form an endless chain travel round inside the rotor. The lifting device can be transported by rolling it on its side 3| or it can be carried.

It will be noted that the construction shown and described will serve admirably to accomplish the objects stated above. It is to be understood, however, that the construction disclosed above is intended merely as illustrative of the invention and not as limiting as various modifications therein may be made without departing from the invention as defined by a proper interpretation of the claims which follow.

I claim: i

1. A lifting device comprising a metal band capable of being wound into spiral form, two members disposed concentrically so as to enclose an annular space therebetween, a helically ascending guide track for said band in said annular space, a slot in the outer of said two concentric members through which said band can pass to said guide track, means for engaging said band with the inner of said two concentric mem' bers and means for rotating one of said concentric members relatively to the other.

2. A lifting device comprising a metal band capable of being wound into spiral form, two members disposed concentrically so as to enclose an annular space therebetwcen, a helically ascending guide track for said band formed in the inner surface of the outer of said concentric members, a slot in the outer of said concentric members through which said band can pass to' said guide track, grooves in the outer surface of the inner of said concentric members, projections on the band for engaging said grooves and means for rotating one of said concentric members relatively to the other.

3. A lifting device comprising a metal band capable of being wound into spiral form, two members disposed concentrically so as to enclose an annular space therebetween, a helically ascending guide track for said band in said annular space, a slot in the outer of said concentric members through which said band can pass to said guide track, means for engaging said band with the inner of said concentric members, projections along one edge of said band, holes along the opposite edge of the band in which said projections on the edge of the adjacent convolution engage when the band is wound into helical form and means for rotating one of said concentric members relatively to the other.

4. A lifting device comprising a metal band capable of being wound into spiral form, a cylindrical stator having grooves in its outer surface, a rotor enclosing said stator so as to form an annular space therebetween, a helically ascending guide track for said metal band in the inner surface of said rotor, a slot in said rotor through which said band can pass to said guide track,

projections on said band for engaging said grooves in said stator, and means for rotating said rotor relatively to said stator, so as to extend the band in the form of a tube in said annular space.

5. A lifting device comprising a metal band capable of being wound into spirial form, two members disposed concentrically so as to enclose an annular space therebetween, a helically ascending guide track for said band in said annular space, rollers on said guide track, a slot in the outer of said two concentric members through which said band can pass to said guide track, means for engaging said band with the inner of said concentric members and means for rotating one of said concentric members relatively to the other.

6. A lifting device comprising a metal band capable of being wound into spiral form, two members disposed concentrically so as to enclose an annular space therebetween, a casing arranged to rotate on bearings around said concentric members in which said band is disposed in spiral form, a helically ascending guide track for said band in said annular space, a slot in the outer of said two concentric members through which said band can pass to said guide track, means for engaging said band with the inner of said concentric members and means for rotating one of said concentric members relatively to the other.

7. A lifting device comprising a metal band capable of being wound into spiral form and for said band-in said annular space, a slot in the outer of said two concentric members through which said band can pass to said guide track, means for engaging said band with the inner of said two concentric members and means for rotating one of said concentric members relatively to the other.

8. A lifting device comprising a metal band capable of being wound into spirial form, two members disposed concentrically so as to enclose an annular space therebetween, a helically ascending guide track for said band in said annular space, rollers on said guide track, straps connecting said rollers so as to form an endless chain, a. slot in the outer of said two concentric members through which said band can pass to said rollers, means for engaging said band with the inner of said two concentric members and means for rotating one of said concentric members relatively to the other.

9. A lifting device comprising a metal band capable of'being wound into spiral form, two members disposed concentricallyso as to enclose an annular space therebetween, a helically ascending guide track for said bandin said annua,17a,ees

lar space, rollers on said guide track, straps connecting said rollers to form an endless chain,

blocks linked together to form an endless chain carried by said rollers for supporting said band, a slot in the outer of said two concentric members through which said band can pass to said blocks, means for engaging said band with the inner of said two concentric members and means for rotating one of said concentric members rela tively to the other.

10. A lifting device as claimed in Claim 9, wherein said blocks are provided with grooves for receiving the edge of the metal band.

11. A lifting device as claimed in Claim 5, wherein said rollers are conical and the guide track on which they are supported slopes up inwardly towards the centre.

12. A lifting device comprising a metal band capable of being wound into spiral form, a cylindrical stator having vertical grooves in its outer surface, a rotor enclosing said stator so as to form an annular space therebetween, a casing mounted to rotate around said rotor and stator in which said band isspirally wound, a helically ascending guide track for said metal band in the inner surface of said rotor, rollers on said guide track, a slot in said rotor through which said band can pass to said guide track, projections on said band for engaging said grooves in said stator, projections along one edge of the band, holes along the opposite edge of the band in which the projections of the adjacent convolutions engage when the band is wound into helical form, and

means for rotating said rotor relatively to said stator.

13. A lifting device comprising a metal band capable of being wound into spiral form, a cylindrical stator having grooves in its outer surface, a rotor enclosing said stator so as to form an annular space therebetween, a helically ascending guide track for said metal band in the inner surface of said rot'or, a slot in said rotor through which said band can pass to said guide track, projections on said band for engaging said grooves in said stator, projections along one edge of the band, holes along the opposite edge of the band in which the projections of the adjacent convolutions engage when the band is wound into helical form and means for rotating said rotor relatively to said stator.

14. A lifting device comprising a metal band having a curved edge and capable of being wound into spiral form, a cylindrical stator having grooves in its outer surface, a rotor enclosing said stator so as to form an annular space therebetween, a helically ascending guide track for said metal band in the inner surface of said rotor, a slot in said rotor through which said band can pass to said'guide track, projections on said band for engaging said grooves in said stator, and means for rotating said rotor relatively to said stator.

15. A lifting device as claimed in Claim 1', wherein the band is composed of links.

ERICH GRASSMANN.