Chain hoist with improved chain entry

Abstract

A chain hoist (10) having an improved chain guide (12) for a link chain (14). The chain guide (12) has a channel (36) with a cross-shaped cross section, through which the link chain (14) extends. An end surface (26) of the chain guide (12) extends away from a mouth opening (28) of the channel (36). The channel (36) establishes a through-passage direction (D) which widens in the direction of the end surface (26), and a protrusion (30) is formed on the end surface (26) around the mouth opening (28) of the channel (36).

Claims

1. A chain hoist (10) comprising a chain guide (12) for guiding movement of a link chain (14) formed of interconnected elongated links 34a, 34b, 34c, said chain guide (12) being formed with a channel (36) which has a cruciform cross-section and through which the link chain (14) extends, said chain guide (12) having an end face (26) having a contour which surrounds and extends away from a mouth opening (28) of said channel (36), said channel (36) having a through-passage direction (D) along which the link chain is moveable in said chain guide channel (36), said chain guide channel (36) widening in the direction toward the end surface (26), a protrusion (30) extending outwardly of the contour on the end surface (26) so as to form an elevation above the end face (26) and through which the mouth opening (28) of the channel (36) extends, and said chain being moveable into said mouth opening (28) and through said chain guide channel (36) with individual elongated links of the link chain (14) passing over the protrusion (30) in sideways relation to the protrusion (30) with ends of the links (34b) above the end face (26) of the chain guide (12) before entering the mouth opening (28) of the channel (36).

2. The chain hoist (10) of claim 1 in which said end face (26) of said chain guide (12) is at least partially arcuate in shape.

3. The chain hoist (10) of claim 1 in which said end surface (26) of the chain guide (12) is inclined relative to the through-passage direction (D).

4. The chain hoist (10) as of claim 1 in which said channel (36) has, in cross-section (Q), two guide groove pairs (38, 40) oriented transversely with respect to each other, and at least one of the guide groove pairs (38, 40) widens in the direction of the end surface (26) with at least one step (46a, b).

5. The chain hoist (10) of claim 1 in which said protrusion (30) has a height (H) of 20% to 80% of a length (l) of a link of the link chain (14).

6. The chain hoist (10) of claim 1 in which said protrusion (30) has at least one planar surface (42a-d).

7. The chain hoist (10) of claim 1 in which said protrusion (30) has at least one arcuate surface (42a-d).

8. The chain hoist (10) of claim 1 in which said protrusion (30) has the form of one of a spherical segment, a conical form, or pyramidal form.

9. The chain hoist (10) of claim 1 in which said chain guide (12) is made of metal.

10. The chain hoist (10) of claim 1 including a lubricating device (44) formed in or on at least one guide groove pair (38, 40).

11. The chain hoist (10) of claim 1 in which said chain guide (12) is a component (15) separate from the remaining chain hoist (10).

12. The chain hoist (10) of claim 1 including at least one swivel hook block.

13. A chain hoist (10) comprising a housing through which a link chain passes, a chain guide (12) for guiding movement of the link chain (14) formed of interconnected elongated links 34a, 34b, 34c through said housing, said chain guide (12) being formed with a channel (36) which has a cruciform cross-section and through which the link chain (14) extends, said chain guide (12) having an end face (26) having a contour which surrounds and extends away from a mouth opening (28) of said channel (36), said channel (36) having a through-passage direction (D) along which the link chain is moveable in said chain guide channel (36), said chain guide channel (36) widening in the direction toward the end surface (26), a protrusion (30) extending outwardly of the contour on the end surface (26) so as to form an elevation above the end face (26) and through which the mouth opening (28) of the channel (36) extends, and said chain being moveable into said mouth opening (28) and through said chain guide channel (36) with individual elongated links of the link chain (14) passing over the protrusion (30) in sideways relation to the protrusion (30) with ends of the links (34b) above the end face (26) of the chain guide (12) before entering the mouth opening (28) of the channel (36).

14. The chain hoist (10) of claim 13 in which said chain guide (12) is a component (15) separate from the housing.

15. The chain hoist (10) as of claim 14 in which said channel (36) has, in cross-section (Q), two guide groove pairs (38, 40) oriented transversely with respect to each other, and at least one of the guide groove pairs (38, 40) widens in the direction of the end surface (26) with at least one step (46a, b).

16. The chain hoist (10) of claim 15 in which said end face (26) of said chain guide (12) is at least partially arcuate in shape.

17. The chain hoist (10) of claim 16 in which said protrusion (30) has a height (H) of 20% to 80% of a length (l) of a link of the link chain (14).

18. The chain hoist (10) of claim 15 in which said protrusion (30) has the form of one of a spherical segment, a conical form, or pyramidal form.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective of an illustrative chain hoist having a chain guide in accordance with the invention;

(2) FIG. 2a is an enlarged perspective of a chain guide in the form of an inserted component in accordance with the invention;

(3) FIG. 2b is a top plan view of the chain guide shown in FIG. 2a

(4) FIG. 3 is a side view of another embodiment of a chain hoist with a chain guide in accordance with the invention;

(5) FIG. 4 is a vertical section of the inventive chain guide; and

(6) FIG. 5 is an enlarged vertical section of the inventive chain guide.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) Referring now more particularly to FIG. 1 of the drawings, there is shown an illustrative chain hoist 10 having a chain guide 12 in accordance with the invention for use with a link chain 14. The chain hoist 10 comprises a housing 16 that can hold a chain sprocket and a motor, and, for example, a slip friction clutch. The chain hoist 10 comprises a hook 18 that, in the exemplary embodiment, is fastened to the housing 16 but also comprises a swivel bearing. The hook 18 can be used for fastening to a load that is to be lifted or to be lowered by the chain hoist 10. The chain hoist 10 comprises a hook block 20 that is connected to the chain 14. The chain 14 moves from the chain guide 12 to the hook block 20 over a roller at the hook block 20 and back again to the housing 16, where the end of the chain 14 is fastened. The fastening means may also be configured as a hook 20 to which the chain is fastened and which does not move back to the housing 16.

(8) The housing 16 has lateral walls 22 and a housing surface 24. Above the chain sprocket provided in the housing, there is a channel 36 of a chain guide 20. The channel 36 terminates in a mouth opening 28 on the surface 24 that, at the same time, represents the end surface 26 of the chain guide 12. Formed at the mouth opening 28, there is a protrusion 30. At the protrusion 30, the chain 14 moves through the mouth opening 28 into the housing 16 of the chain hoist 10.

(9) The hook block 20 can be hooked at a fastening height to a stage scaffolding, for example. The load is fastened to the hook 18 and moved up and down on the chain 14, together with the housing 16. In the exemplary embodiment, the hook block 20 is equipped with a swivel bearing 32 and, in this manner, configured as a swivel hook. Therefore, the hook block 20 can be rotated, without the link chain 14 being twisted.

(10) In the depicted exemplary embodiment, the chain hoist 10 is in a state that approximately corresponds to the initial state at the place of use. The link chain 14 extends through the housing 16 in a stored condition. With the aid of the lifting motor, the chain 14 is moved out of the housing and hooked at a fastening height above the stage floor. A load fastened to the hook 18 can then be lifted with the chain hoist 10, in which case the chain 14 is retracted through the mouth opening 28 through the housing surface/end surface 24, 26.

(11) After its use, the housing 16 is lowered to the stage floor and the hook block 20 is detached from the stage scaffolding. The chain 14 is deposited on the housing surface 24 or on the end surface 26 and retracted through the mouth opening 28 by means of the lifting motor. The protrusion 30 may be configured, for example, as a component of the housing surface 24 projecting from the otherwise plane housing surface, or may be added as a superstructure to the housing surface 24 or be an insert in the housing 16.

(12) FIGS. 2a and 2b show an inventive chain guide 12 as a separate component 15. The component 15 may be immovably or movably connected to the housing 16, for example with screws, cement or by welding. The chain guide of the exemplary embodiment may be set up as an insert or as an attachment for a housing 16 of a chain hoist 10. FIG. 2a is a perspective view and FIG. 2b is a plan view of a chain guide in accordance with the invention. The chain guide 12 has a channel 36 with a cruciform cross-section Q. FIG. 2b shows a cross-section Q of the channel 36. The channel 36 has a first guide groove pair 38 and a second guide groove pair 40 that are oriented transversely with respect to each other. The end surface 26 of the chain guide 12 extends from the mouth opening 28 of the channel 36, away from said channel. Considering the depicted exemplary embodiment, the end surface 26 drops obliquely downward in an inclined direction R relative to the through-passage direction D. The end surface 26 is curved in a convex manner, but it may also be straight, for example.

(13) The channel 36 defines a through-passage direction D. In the exemplary embodiment, the first 42a, second 42b, third 42c and fourth protrusion surface 42d are curved around the mouth opening 28 of the protrusion 30. In doing so, the protrusion 30 has the form of a spherical segment. Protrusion surfaces 42a-d, may also drop obliquely downward, for example, thus resulting in the form of a pyramid. One or more protrusion surfaces 42a-d may also extend horizontally or parallel to the end surface 26. A guide groove pair 38, 40 hasin cross-sectiona first extension L and a second extension W. The first extension L and the second extension W of the first guide groove pair 38 and the second guide groove pair 40 may be different. The first extensions L of the first and the second guide groove pairs of the channel 36 increase at least in a mouth opening section of the channel counter the through-passage direction or in the direction of the end surface 26. This means that the channel 36 widens in the direction counter the through-passage direction. In the first and the second guide groove pairs 38,40, there may be a lubricating device 44, for example in the form of a lubricating felt. Due to the first through the fourth protrusion surfaces 42a-d the end surface 26 is continued beyond the protrusion 30. The protrusion 30 extends over the mouth opening 28, i.e., radially over the channel 36. The protrusion 30 is centered on the mouth opening 28.

(14) FIG. 3 shows a side view of a chain guide 12 for a chain hoist 10 in which a first chain link 34a is depicted that belongs to a chain section extending through the channel 36. A second chain link 34b is positioned sideways to illustrate the rotating mechanism relative to the mouth opening 28. Furthermore, the chain link 34b is shown positioned sideways relative to the end surface 26. A third chain link 34c following the sideways positioned second chain link 34b is oriented approximately along the end surface 26 and abuts against the first and the second protrusion surfaces 42a, b of the protrusion 30. The chain link has a length l, a division t, an inside width b1, an outside width b2, a width of the chain link body b, and a thickness d. The protrusion 30 has a height H relative to the end surface 26 (see FIGS. 4 and 5). Preferably, the height H is approximately 20% to 80% of the chain link length l. In the region of the protrusion 30, the channel 36 extends over a first extension L (see FIG. 2b) that allows a rotation of the sideways positioned chain link 34b.

(15) The chain guide in accordance with FIG. 2 may be made of metal. The chain guide may also comprise plastic. For example, the protrusion and/or parts of the protrusion may consist of plastic. It is also possible to use other materials such as, for example, wood, rubber and/or carbon, for the chain guide or for parts of the chain guide.

(16) FIG. 4 shows a cross-section along the through-passage direction D through the channel 36, in particular the first guide groove pair 38. As apparent, the channel 36 widens in the direction toward the end surface 26 counter the through-passage direction D. The channel initially has a first extension having the dimension L1 and a mouth-opening-side part of the channel 36 has a first extension having the dimension L2. The transition occurs in steps, with a first step 46a first on the first side 38a and in the direction of the end surface 26 with a second step 46b on the other side 38b, thus resulting in an asymmetrical cross-section of the channel 36. In the region of the mouth opening 28 the channel 36 is widened so that a rotation of the sideways oriented chain link 34b is possible.

(17) FIG. 5 shows another cross-sectional view of a chain guide 12 having a cross-section through the channel 36, in particular the second guide groove pair 40. The channel 36 terminates at the mouth opening 28. The second guide groove pair 40 of the channel 36 widens symmetrically and monotonously in the direction toward the end surface 26 along a straight line from the first extension having the dimension L1 to a first extension having the dimension L2.

(18) In all embodiments, a sensor, e.g., a switch, can be provided to detect any potential chain jamming. For example, the component may be movable against the force of a spring in the direction of the channel 36 and actuate a correspondingly arranged switch. The signal emitted by the switch may act to stop or reverse the driving motor.

(19) From the foregoing, it can be seen that a chain hoist 10 in accordance with the invention is provided that has an improved chain guide 12 for a link chain 14. The chain guide 12 comprises a channel 36 having a cruciform cross-section through which the link chain 14 may extend. An end surface 26 of the chain guide 12 extends from a mouth opening 28 of the channel 36, away from said channel. The channel 36 defines a through-passage direction D which widens in the direction of the end surface 26, and a protrusion 30 is formed on the end surface 26 around the mouth opening 28 of the channel 36.

LIST OF REFERENCE SIGNS

(20) TABLE-US-00001 10 Chain hoist 12 Chain guide 14 Link chain 15 Structural component 16 Housing 18 Hook 20 Hook block 22 Lateral walls 24 Housing surface 26 End surface 28 Mouth opening 30 Protrusion 32 Pivot bearing 34 (a-c) Chain link 36 Channel 38 First guiding groove pair 38 a, b First and second sides 40 Second guiding groove pair 42 a-d first to fourth protruding surfaces 44 Lubricating device 46 a, b First and second steps R Oblique direction D Through-passage direction L First extension L1, L2 Dimensions of the first extension W Second extension b1 Inside width b2 Outside width b Width d Thickness l Length t Division H Height Q Cross-section