Lever hoist

Abstract

The invention relates to a lever hoist (1) comprising a housing (2) in which a hoist chain sprocket (15) and a drive shaft (19), which drives the hoist chain sprocket (15) via a gear mechanism (16), are rotatably mounted, wherein a drive torque can be transmitted to the drive shaft (19) via a lever (11), and a hoist chain (9) can be moved over the hoist chain sprocket (15), and wherein the lever (11) can be shifted into a neutral position in which the lever (11) is decoupled from the drive shaft (10). Also provided is a drive element (42) which is indirectly or directly coupled to the drive shaft (19) for coupling to a power tool (48) so that a drive torque can be transmitted to the drive shaft (19) by means of the power tool (48).

Description

[0001] lever pull

[0002] The present invention relates to a lever pull according to the features in the preamble of claim 1.

[0003] Lever hoists are used for lifting, lowering and pulling loads and often employ round steel chains as load-bearing or pulling means.

[0004] EP 4263414 B1 discloses such a manually operated lever hoist, which comprises a housing in which a load sprocket and a drive shaft, which drives the load sprocket via a gearbox, are rotatably mounted. A torque can be transmitted to the drive shaft via a lever. The lever can be manually operated by a user of the lever hoist. A load chain can be moved via the load sprocket. The lever can also be moved into a neutral position in which the lever is decoupled from the drive shaft.

[0005] Manually operated lever hoists have the advantage of being usable anywhere, especially without electricity. Furthermore, precise and controlled force can be applied to the lever using hand strength, allowing for sensitive positioning of the load. However, a disadvantage is that the physical exertion required can lead to fatigue, particularly with repeated use.

[0006] CN 118651 788 A discloses a lever mechanism with a sprocket and brake nut, which are coupled to each other via a threaded connection and controlled by a drive and a brake. A drive element can be coupled either to a lever or to an electrical device.

[0007] From JP H10338476 A a chain hoist is known in which the drive torque can be transmitted to the drive shaft either via a lever or via an electric drive element.

[0008] Further state of the art is defined by US 2010 / 133372 A1.

[0009] Based on this, the object of the present invention is to provide an improved lever mechanism that enables fatigue-free and precise lifting of loads. According to the invention, this object is achieved by a lever mechanism with the features of claim 1.

[0010] Advantageous embodiments of the invention are the subject of the dependent claims.

[0011] The lever system according to the invention comprises a housing in which a load sprocket and a drive shaft, which drives the load sprocket via a gearbox, are rotatably mounted. A drive torque can be transmitted to the drive shaft via a lever, in particular a hand lever. A load chain can be moved via the load sprocket.

[0012] The core concept of the invention is that, in addition to the lever, a drive element is provided for coupling with a power tool, either directly or indirectly, such that a drive torque can be transmitted to the drive shaft by means of the power tool. To prevent rotation of the lever during operation by the power tool, the lever can be moved into a neutral position in which it is decoupled from the drive shaft. In the context of the invention, "decoupled" means that when the lever is actuated, no torque is transmitted to the drive shaft. Conversely, in the decoupled state of the lever, no torque is transmitted from the drive shaft to the lever.

[0013] The lever mechanism according to the invention can thus be driven either manually by means of the lever or alternatively by means of a power tool, in particular a cordless screwdriver. This offers the advantage that precise positioning of the load coupled to the lever mechanism can be achieved by manually applying a metered force to the lever. If, on the other hand, a load needs to be lifted over a greater distance, it can be lifted comfortably by means of the coupling option with a power tool according to the invention, without causing fatigue to the user. Since the lever can be moved into a neutral position according to the invention, it is not moved by the torque transmitted from the power tool to the drive shaft when the lever mechanism is coupled to the power tool and remains in its neutral position.If the lever is operated manually using the lever, the power tool can be decoupled from the drive element of the lever. In this case, the drive element coupled to the drive shaft can rotate freely without impairing the function of the lever. The lever according to the invention thus combines the advantages of a manual lever with those of an electrically operated lever.

[0014] The invention also relates to a lever pull arrangement comprising the lever pull and the power tool coupled to the lever pull.

[0015] Furthermore, the invention relates to a lever pull kit, which consists of the lever pull and the associated power tool.

[0016] The lever mechanism incorporates a load-pressure brake. The purpose of the load-pressure brake is to securely hold the raised load and prevent uncontrolled lowering when no torque is transmitted to the drive shaft via the lever or the drive element. It ensures that the load is only moved when the operator actuates the lever mechanism via the lever or the power tool connected to the lever mechanism. The load-pressure brake includes a ratchet wheel mounted on the drive shaft. The ratchet wheel has drive teeth on its outer circumference.

[0017] The lever preferably has a pawl body, in particular a pawl rod. The pawl body is designed to be displaceable and can be engaged with the drive teeth of the ratchet wheel such that the lever is in the neutral position when the pawl body is not engaged with the drive teeth. Thus, in its neutral position, the lever is decoupled from the ratchet wheel and therefore from the drive shaft. Rotation of the lever therefore does not cause rotation of the drive shaft, and vice versa. This design has the advantage that the neutral position can be set directly by the user via the lever. When the lever is in the neutral position, torque can be transmitted to the drive shaft via the power tool coupled to the drive element without the lever rotating simultaneously. This allows for safe operation of the lever pull using the power tool.

[0018] Preferably, the load-pressure brake further comprises a pressure disc arranged on the drive shaft and non-rotatably connected to it, as well as a ratchet wheel disc, wherein the ratchet wheel disc is integrated between the pressure disc and the ratchet wheel. The ratchet wheel disc is particularly provided on both sides with friction elements in the form of friction linings. Most preferably, the load-pressure brake has two pawls pivotally mounted in the housing, which are pressed against the ratchet wheel disc under the influence of pawl springs.

[0019] The ratchet wheel is preferably mounted with an internal thread on a threaded section of the drive shaft that also has a brake thread, allowing it to be axially displaceable. When the ratchet wheel is rotated in the lifting direction, it is pressed against the pressure plate, which is fixedly connected to the drive shaft, via the ratchet wheel disc and the integrated friction elements, so that the drive shaft rotates with the ratchet wheel. During this rotation, the pawls slide over the teeth of the ratchet wheel disc. When no more torque is transmitted to the ratchet wheel and it comes to a standstill, the pawls re-engage in the recess of the ratchet wheel disc, and the load is held.

[0020] When the load is lowered, the ratchet wheel rotates in the opposite direction, causing it to slide axially on the brake thread of the drive shaft and thus breaking the frictional contact with the friction elements of the ratchet wheel disc and the pressure plate. The load can then lower until the rotating drive shaft compensates for the axial play again.

[0021] The ratchet wheel has an additional toothed ring on its outer circumference. This toothed ring is not the drive tooth. The drive element engages with the toothed ring. Rotation of the drive element by the power tool thus causes the ratchet wheel to rotate, thereby transmitting torque to the drive shaft. The toothed ring can be bonded to the outer circumference of the ratchet wheel or be an integral part of the ratchet wheel.

[0022] The drive element is, in particular, a drive pinion which has a toothed profile on its outer circumference and is rotatably mounted within the housing. In this case, the toothed profile of the drive pinion engages with the ring gear or drive teeth of the ratchet wheel and enables the coupling between the drive element and the ratchet wheel. Preferably, the drive element has a receptacle, which is in particular an internal square or internal hexagon socket. The receptacle serves to couple the power tool to the drive element and enables a secure connection.

[0023] Preferably, the drive element, in particular the drive pinion, is mounted on a shaft inside the housing, with a shear pin connecting the drive element to the shaft. The shear pin serves as an overload protection device, so that both the lever pull and the user are protected from excessive torque peaks.

[0024] The invention is explained in more detail below with reference to purely schematic drawings. These show:

[0025] Figure 1 shows a lever pull according to the invention in a side view;

[0026] Figure 2 shows the lever in an exploded view of its components;

[0027] Figure 3 shows the lever pull with coupled lever in a side view;

[0028] Figure 4 shows the lever pull in section AA of Figure 3;

[0029] Figure 5 shows the lever pull in section BB of Figure 3;

[0030] Figure 6 shows the lever pull with decoupled lever in a side view;

[0031] Figure 7 shows the lever pull in section CC of Figure 6;

[0032] Figure 8 shows the lever pull in section DD of Figure 3 and Figure 7;

[0033] Figure 9 shows the lever pull in section EE of Figure 3 and Figure 7;

[0034] Figure 10 shows the lever pull in the coupled state with a power tool;

[0035] Figure 11 shows a ratchet wheel in an exploded view of its components and

[0036] Figure 12 shows a lever in an exploded view of its components.

[0037] The same reference numerals are used for identical or corresponding components, even if a repeated description is omitted for the sake of simplicity. Figures 1 to 10 show a lever hoist 1 according to the invention. The lever hoist 1 comprises a housing 2, which consists of several housing parts 3, 4, as well as side plates 5 and a spacer frame 6. The lever hoist 1 has a support hook 7 as an upper fastening element and a load hook 8 as a lower stop element. The support hook 7 and the load hook 8 are indirectly connected to each other via the housing 2. The load hook 8 is attached to one end of a load chain 9. A chain end piece 10 is provided at the other end of the load chain 9. The load chain 9 can be moved via a traction drive. The traction drive comprises a drive with a lever 11, a reversible ratchet mechanism 12, a load pressure brake 13 with a ratchet wheel 14, a load sprocket 15, and a gearbox 16.

[0038] In the lever 11, a ratchet body 17 in the form of a ratchet rod is spring-loaded and longitudinally displaceable. The lever 11 with the ratchet body 17 and the ratchet wheel 14 are located at one end section 18 of a drive shaft 19, which passes through the load pressure brake 13 and the load sprocket 15. At the other end section 20 of the drive shaft 19 is the gearbox 16, which is connected to the load sprocket 15 in a torque-transmitting manner. A handwheel 21 serves to move the ratchet wheel 12 axially on the drive shaft 19 in order to actuate a freewheel mechanism 22 of the lever pull 1. The axial stroke is limited by a locking element 38.

[0039] The load-pressure brake 13 has a ratchet wheel 23 with teeth on its outer circumference. The ratchet wheel 23 is provided on both sides with friction elements 24 in the form of friction linings. This is shown in particular in Figure 9. Furthermore, the load-pressure brake 13 has two pawls 25 pivotally mounted in the housing 2 on the side plate 5, which are pressed against the ratchet wheel 23 by the influence of locking hook springs 26.

[0040] The load pressure brake 13 also includes a pressure plate 27, on which the ratchet wheel 23 is mounted. The ratchet wheel 14 is axially displaceable on a threaded section 29 of the drive shaft 19, which has a brake thread 28.

[0041] The load-pressure brake 13 has the function of holding the load carried by the lever 1 when the ratchet wheel 14 is stationary. In this position, the ratchet wheel 14 is pressed against the pressure plate 27 via the ratchet wheel disc 23 and the integrated friction elements 24. The ratchet wheel pawls 25 are located in the circumferential recesses of the ratchet wheel disc 23. When the ratchet wheel 14 is rotated in the raising direction, the pawls 25 slide over the teeth of the ratchet wheel disc 23 until the ratchet wheel 14 comes to a standstill. The pawls 25 then engage again in the recess of the ratchet wheel disc 23. When the load is lowered, the ratchet wheel 14 is rotated in the opposite direction, causing it to slide axially on the brake thread 28 of the drive shaft 19 and releasing the frictional contact with the friction elements 24 of the ratchet wheel disc 23 and the pressure plate 27. The load can then lower itself until the rotation of the drive shaft 19 compensates for the axial play.

[0042] The construction of the ratchet wheel 14 is shown in detail in Figure 11. The ratchet wheel 14 has a drive toothing 30 on its outer circumference. The drive toothing 30 has axially extending teeth with grooves arranged between them. The area with the drive toothing 30 extends over a first longitudinal section of the ratchet wheel 14, viewed from the handwheel 21. The ratchet wheel 14 has a hollow cylindrical configuration and a hollow chamber 31. The handwheel 21 is fixed to the end face of the circumferential outer wall 32 of the ratchet wheel 14 by means of fastening screws 33. A central through-hole 35 with an internal thread 36 is located in the base 34 of the ratchet wheel 14. The ratchet wheel 14 moves on the brake thread 28 of the drive shaft 19 via the internal thread 36. A sliding ring 61 is also arranged inside the ratchet wheel 14.

[0043] The drive shaft 19 passes through the ratchet wheel 14, the drive shaft 19 having an end-mounted pinion section 37 adjacent to the brake thread 28, which engages with the locking element 38. The locking element 38 is fixed to the drive shaft 19 by means of a lock nut 39. The locking element 38 and the lock nut 39 are arranged within the hollow chamber 31 between the ratchet wheel 14 and the handwheel 21.

[0044] A compression spring 41 is clamped between the locking element 38 and a stop 40 of the handwheel 21. The spring force F1 of the compression spring 41 acts in the direction of the opening movement of the load pressure brake 13. The spring force F1 thus assists the opening of the load pressure brake 13. A compression spring 60 is also clamped between the pressure disc 27 and the ratchet wheel 14, whose spring force F2 also acts in the direction of the spring force F1 and also assists the opening movement of the load pressure brake 13. In normal manual operation, the pawl body 17 of the ratchet mechanism 12 engages in the grooves between the teeth of the drive gear 30 of the ratchet wheel 14. This operating state is shown in Figures 3 and 4. A torque applied to the lever 11 is transmitted to the ratchet wheel 14 via the pawl body 17.The torque is transmitted from the ratchet wheel 14 to the ratchet wheel disc 23 by means of the friction elements 24, which in turn transmits the torque to the pressure disc 27 which is connected to the drive shaft 19 in a rotationally fixed manner.

[0045] According to the invention, the drive further comprises a drive element 42, which is indirectly coupled to the drive shaft 19. The drive element 42 is a drive pinion, which is rotatably mounted within the housing 2. The ratchet wheel 14 has a toothed rim 43 on its outer circumference. The toothed rim 43 is fixed to the outer circumference of the ratchet wheel 14 by means of two spiral rings 44 and a key 45. This is shown in particular in Figure 11.

[0046] The toothed ring 43 is located at the opposite end of the ratchet wheel 14 with respect to the drive teeth 30. The drive element 42 has a toothed profile 46 on its outer circumference, which engages with the toothed ring 43. This is shown in particular in the sectional views of Figures 5 and 8. The toothed profile 46 is connected to a shaft section 59 of the drive element 42 by means of a shear pin 58. Rotation of the drive element 42 results in rotation of the ratchet wheel 14.

[0047] The drive element 42 has a receptacle 47 for coupling with a power tool 48. In this case, the receptacle is an internal square drive. The power tool 48 is a cordless screwdriver. The coupling between the power tool 48 and the lever 1 is shown in Figure 10. The cordless screwdriver can be coupled to the receptacle 47 of the drive element 42 by means of a bit attachment. When the power tool 48 is actuated, this generates a rotation of the drive element 42, which in turn results in a rotation of the ratchet wheel 14 and thus indirectly a rotation of the drive shaft 19. The lever 1 according to the invention can therefore be operated both manually by means of the lever 11 and electrically by means of the power tool 48.

[0048] To prevent rotation of the lever 11 during electrical operation using the power tool 48, the lever 11 can be moved into a neutral position in which it is decoupled from the drive shaft 19. Figures 6 and 7 show the lever 11 in the neutral position. The construction of the lever 11 is also shown in Figure 12. To decouple the lever 11 from the ratchet wheel 14, the pawl body 17, which is mounted inside the lever 11 and is in this case a pawl rod, can be moved towards the lever end 49. For this purpose, the pawl body 17 is coupled at its end to a shift lever 50, which the user can use to pull the pawl body 17 towards the lever end 49 and fix it there by rotating it. In the neutral position, the pawl body 17 is therefore no longer in contact with the ratchet wheel 14.

[0049] To enable the user to always see whether the lever 11 is in the neutral position, the lever 11 has an opening 51 that provides a view into an interior space 52 of the lever 11. A switching sleeve 53 is arranged within the interior space 52, and the switching sleeve 53 is fixed to the latch body 17 by means of a clamping pin 54. The switching sleeve 53 has a characteristic symbol 55 for the coupled and uncoupled states, respectively. This could be, for example, an N for neutral or a triangle to indicate the coupled state. Depending on the displacement state of the latch body 17, the symbol for the neutral position or the symbol for the coupled state is thus visible through the opening 51 of the lever 11.

[0050] A compression spring 57 for the pawl body 17 is arranged between the shift sleeve 53 and a rear wall 56 of the interior 52. The compression spring 57 presses the pawl body 17, in the coupled state between the lever 11 and the ratchet wheel 14, into the grooves of the drive teeth 30 of the ratchet wheel 14, so that the pawl body 17 engages with the drive teeth 30. (Reference symbol:)

[0051] 1 - Lever pull

[0052] 2 - Housing

[0053] 3 - Housing part

[0054] 4 - Housing part

[0055] 5 - Side panel

[0056] 6 - Distance frame

[0057] 7 - Carrying hooks

[0058] 8 - Load hooks

[0059] 9 - Load chain

[0060] 10 - Chain end piece

[0061] 11 - Lever

[0062] 12 - Ratchet mechanism 13 - Load pressure brake

[0063] 14 - Ratchet wheel

[0064] 15 - Load sprocket

[0065] 16 - Gearbox

[0066] 17 - Door handle body

[0067] 18 - End section of 19 19 - Drive shaft

[0068] 20 - End section of 19 21 - Handwheel

[0069] 22 - Freewheel mechanism 23 - Ratchet wheel disc

[0070] 24 - Friction element

[0071] 25 - Locking pawl

[0072] 26 - Locking hook spring

[0073] 27 - Pressure plate

[0074] 28 - Brake thread

[0075] 29 - Threaded section 30 - Drive gear 31 - Hollow chamber 2 - Outer wall of 14

[0076] 3 - Mounting screws

[0077] 4 - Bottom of 14

[0078] 5 - Feedthrough opening

[0079] 6 - Internal thread of 14

[0080] 7 - Sprocket section

[0081] 8 - Safety element

[0082] 9 - Lock nut

[0083] 0 - Stop from 21

[0084] 1 - Compression spring

[0085] 2 - Drive element

[0086] 3 - Sprocket

[0087] 44 - Spiral ring

[0088] 45 - Keyway

[0089] 46 - Tooth profile

[0090] 47 - Recording

[0091] 48 - Power tools

[0092] 49 - End of 11

[0093] 50 - Gearshift lever

[0094] 51 - Opening

[0095] 52 - Interior

[0096] 53 - Switch sleeve

[0097] 54 - Tension pin

[0098] 55 - Symbol

[0099] 56 - End side inner wall of 52 57 - Compression spring

[0100] 58 - Shear pin

[0101] 59 - Shaft section of 42 60 - Compression spring

[0102] 61 - Sliding ring

[0103] F1 - Spring force of 41

[0104] F2 - Spring force of 60

Claims

Patent claims 1. Lever pull (1) comprising a housing (2) in which a load sprocket (15) and a drive shaft (19) driving the load sprocket (15) via a transmission (16) are rotatably mounted, wherein a drive torque can be transmitted to the drive shaft (19) via a lever (11) and a load chain (9) can be moved over the load sprocket (15), wherein the lever (11) can be moved into a neutral position in which the lever (11) is decoupled from the drive shaft (19), wherein a drive element (42) is provided for coupling with a power tool (48) indirectly or directly coupled to the drive shaft (19), such that a drive torque can be transmitted to the drive shaft (19) by means of the power tool (48), characterized in that a load pressure brake (13) is provided which has a ratchet wheel (14) arranged on the drive shaft (19),wherein the ratchet wheel (14) has a drive toothing (30) and a toothed ring (43) on its outer circumference, wherein the drive element (42) engages with the toothed ring (43).

2. Lever pull (1 ) according to claim 1 , characterized in that the load pressure brake (13) comprises a pressure disc (27) arranged on and coupled to the drive shaft (19) and a ratchet wheel disc (23), wherein the ratchet wheel disc (23) is integrated between the pressure disc (27) and the ratchet wheel (14).

3. Lever pull (1 ) according to claim 1 or 2, characterized in that the ratchet wheel (14) with an internal thread (36) is axially displaceable on a threaded section (29) of the drive shaft (19) having a brake thread (28).

4. Lever pull (1) according to any one of claims 1 to 3, characterized in that the lever (11) has a pawl body (17), in particular a pawl rod, wherein the pawl body (17) is displaceable and can be engaged with the drive teeth (30) of the ratchet wheel (14) such that the lever (11) is in the neutral position when the pawl body (17) is not engaged with the drive teeth (30).

5. Lever pull (1) according to any one of claims 1 to 4, characterized in that the drive element (42) is a drive pinion which has a tooth profile (46) on its outer circumference and is rotatably mounted within the housing (2).

6. Lever pull (1 ) according to one of claims 1 to 5, characterized in that the drive element (42) has a receptacle (47), in particular an internal square or internal hexagon receptacle for coupling with the power tool (48).

7. Lever pull (1 ) according to claim 5 or 6, characterized in that the tooth profile (46) is connected to a shaft section (59) of the drive element (42) by means of a shear pin (58).

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