Lifting device

Abstract

A suspended manually-driven chain crane capable of lifting, receiving and lowering loads suspended on a chain and a hook by using a sprocket embedded in a spherical helical gear driven by the rotational motion of a ring having an internal thread, the ring with internal threads is coupled to a drive gear engaged by a drive chain pulled by an operator. The overload prevention and detection system provides safety to prevent an operator from attempting to lift a load whose weight exceeds the system capability.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63,524,880, filed July 4, 2023, and U.S. Patent Application No. 18 / 731,875, filed June 3, 2024, the disclosures of which are incorporated herein by reference. Background Technology

[0003] This application relates to a manually driven chain crane, also known as a manual chain crane, for lifting and lowering heavy loads.

[0004] The crane consists of a load chain, a drive chain, a gear set, a hook, and a braking system for holding the load while it is suspended. The load chain wraps around a sprocket, and when the operator pulls the drive chain, the load chain engages the gears, disengaging the braking system and causing the sprocket to rotate. This rotation allows the chain crane to lift or lower the load.

[0005] Manually driven chain cranes are commonly used in industrial environments, construction sites, workshops, warehouses, and other environments requiring the lifting or movement of heavy objects. They are particularly useful when there is no power supply or when available space is limited for larger lifting equipment such as cranes or forklifts.

[0006] These cranes are manually operated by pulling chains, which achieves mechanical advantages through a gear system. This allows operators to lift heavy loads with less effort compared to directly lifting the load. The lifting capacity of manually driven chain cranes varies, ranging from hundreds of kilograms to several tons, depending on the specific crane's design and specifications.

[0007] Current manually driven chain crane technology also includes a load-limiting mechanical switch at the operator's location via a clutch, typically sold separately as an add-on feature. If the operator attempts to lift a load exceeding the crane's capacity, the clutch discs begin to slip, and the operator will be unable to transmit power to the load chain sprocket via the drive gears. This load-limiting mechanical switch is costly and requires factory setting during assembly by adjusting the torque of the locking nut.

[0008] Additionally, an operator may circumvent this overload protection system simply by increasing the applied torque of the locking nut, which will not prevent an accident from occurring. Summary of the Invention

[0009] According to this application, a suspended manually driven chain crane for lifting, supporting, and lowering loads suspended on chains and hooks employs a sprocket built into a spherical helical gear driven by the rotational motion of a ring with an internal helical groove, the ring being coupled to a transmission gear engaged by a transmission chain adapted for operator pulling. An overload prevention and detection system provides safety to prevent the operator from attempting to lift loads exceeding the system's capacity.

[0010] The subject matter of the invention is specifically pointed out and explicitly claimed in the concluding section of this application. However, the organization and operation methods, as well as other advantages and embodiments, are best understood by referring to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals denote like elements. Attached Figure Description

[0011] Figure 1 This is a front view of the lifting device according to the present invention;

[0012] Figure 2 yes Figure 1 A side view of the lifting device;

[0013] Figure 3 It is along Figure 1 A cross-sectional view of the lifting device taken from line 3-3;

[0014] Figure 4 It is along Figure 1 The cross-sectional view of the lifting device taken from line 4-4; and

[0015] Figure 5 It is along Figure 1 The cross-sectional view of the lifting device is taken from line 5-5. Detailed Implementation

[0016] The system according to a preferred embodiment of this application includes a lifting device.

[0017] Referring to the accompanying drawings, the present invention relates to a manually driven chain hoist 16 with a compact structure, characterized by a sprocket integrated into a spherical helical gear 1 driven by a ring 5 with internal helical grooves. When a rotational force is applied to the ring 5 with internal helical grooves, the helical grooves of the ring 5 mesh and drive the toothed spherical helical gear 1. When no rotational force is applied, the ring 5 with internal helical grooves can lock the rotational movement of the spherical helical gear 1 by the frictional force generated by the contact between the helical grooves of the ring 5 with internal helical grooves and the teeth of the spherical helical gear 1.

[0018] The sprocket built into the spherical helical gear 1 meshes with the chain 2, which holds the load through the hook 15.

[0019] A ring 5 with an internal helical groove is assembled within a transmission gear 4. A spherical helical gear 1 rotates on a pair of bearings 10 mounted on a shaft 8. The shaft 8 is positioned on axis x. The ring 5 with the internal helical groove rotates together with the transmission gear 4 by means of a pin 11. Both the ring 5 with the internal helical groove and the transmission gear 4 rotate about axis y via a ball assembly 6, which is orthogonal to but not coplanar with axis x. The ball assembly rolls on circular races placed on two planes of the ring 5 with the internal helical groove and the transmission gear 4, also centered on axis y. The ball assembly 6 is guided on the circular races of fixed housings 12 and 14. Housings 12 and 14 are secured together by fasteners 13. Housings 12 and 14 are characterized by providing holes for guiding chain 2. The transmission gear 4 engages with a transmission chain 3 guided by an outer ring 9. When the pulling force required to lift the load applied to the drive chain 3 exceeds the shear resistance of the pin 11, the drive gear 4 creates a shear cut on the pin 11. Therefore, the pin 11 acts as a fuse to prevent the manual operation of the chain crane 16 from exceeding its maximum load capacity. Thus, the pin serves as an overload protection system.

[0020] Furthermore, the pin system will be able to detect and provide clear notification of such overload attempts through pin failure. Subsequently, the manual chain crane will become inoperable and will require maintenance. This provides an extremely safe system and protects the company from the misuse of equipment by its employees.

[0021] The manually driven chain crane 16 is suspended on the hook 7 mounted on the housing 12.

[0022] Therefore, an improved lifting device is provided that eliminates the need for a load brake, as is typically required in classic worm gear drive systems, and is offered in a much more compact design. An overload protection and detection system is provided to enhance safety against misuse. When the operator releases the drive chain, the chain drive system does not require an additional brake to maintain the load; that is, the load will not fall.

[0023] While preferred embodiments of the present technology have been shown and described, it will be apparent to those skilled in the art that many changes and modifications can be made without departing from the broader aspects. The appended claims are therefore intended to cover all such changes and modifications that fall within the true spirit and scope of the described technology. Claims (as amended under Article 19 of the Treaty) 1. A manually operated chain crane, comprising: Load chain sprocket, Two convex-toothed spherical helical gears inside a cylindrical ring with an inner spiral pattern; The load chain sprocket is driven by the spherical helical gear driven by the ring with internal helical grooves. 2. The manual chain crane according to claim 1, further comprising a rotary transmission gear, wherein the ring having an internal helical pattern rotates together with the rotary transmission gear. 3. The manual chain crane according to claim 2, further comprising an engagement pin for drive engagement between the rotary transmission gear and the ring having an internal helical pattern. 4. A manually operated chain crane, comprising: The sprocket in a spherical helical gear, A ring with an internal spiral pattern; The sprocket is driven by the ring with an internal helical pattern. Furthermore, it includes: A rotary transmission gear, wherein the ring with internal helical grooves rotates together with the rotary transmission gear; and A meshing pin, used for drive engagement between the rotary transmission gear and the ring with internal helical grooves. The pin is adapted to disengage from the drive engagement between the rotary transmission gear and the ring with internal helical grooves under overload conditions. 5. The manual chain crane according to claim 4, wherein the pin disengagement is caused by the pin breaking. 6. The manual chain crane of claim 2, further comprising a drive chain that engages the rotary drive gear to allow an operator to rotate the rotary drive gear. 7. The manual chain crane according to claim 1, further comprising a load chain meshing with a load chain sprocket in the spherical helical gear, the load chain being used to maintain the load supported by the manual chain crane. 8. The manual chain crane according to claim 1, wherein the load chain sprocket is built into the spherical helical gear and runs inside the ring having an inner helical pattern.

Claims

1. A manual chain hoist comprising: a sprocket in a spherical helical gear, a ring having internal helical threads; wherein the sprocket is driven by the ring having internal helical threads.

2. The manual chain hoist of claim 1, further comprising a rotating drive gear, the ring having internal helical threads rotates with the rotating drive gear.

3. The manual chain hoist of claim 2, further comprising an engagement pin for drive engagement between the rotating drive gear and the ring having internal helical threads.

4. The manual chain hoist of claim 3, wherein the pin is adapted to disengage from drive engagement between the rotating drive gear and the ring having internal helical threads in the event of an overload condition.

5. The manual chain hoist of claim 4, wherein the pin disengagement is caused by the pin breaking.

6. The manual chain hoist of claim 2, further comprising a drive chain, the drive chain engaging the drive gear to allow an operator to rotate the drive gear.

7. The manual chain hoist of claim 1, further comprising a load chain, the load chain engaging the sprocket in the spherical helical gear, the load chain for holding a load supported by the manual chain hoist.

8. The manual chain hoist of claim 1, wherein the sprocket built into the spherical helical gear runs inside the ring having internal helical threads.

Images