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Title:
SWIFT HOIST AND OPERATING MODES THEROF
Document Type and Number:
WIPO Patent Application WO/2021/028947
Kind Code:
A1
Abstract:
The invention provides a material handling device or a hoist to lift and lower a load or to move a load from one place to another with different operating modes with a provision of variable speeds to suit lifting / moving of different loads. The invention also provides a hoist capable of picking load from and dropping load at different heights in a manual operation mode as well as in a manual operation assisted by set program mode. The said hoist with different load attachments is ideal to lift different types of loads enabling precise movement of loads particularly for assembly.

Inventors:
BILLA SATISH RAMKRISHNA (IN)
Application Number:
PCT/IN2020/050709
Publication Date:
February 18, 2021
Filing Date:
August 13, 2020
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
BILLA SATISH RAMKRISHNA (IN)
International Classes:
B66D3/18
Foreign References:
US20030127635A12003-07-10
US20070205405A12007-09-06
Attorney, Agent or Firm:
KHARKAR, Pallavi et al. (IN)
Download PDF:
Claims:
Claims

I Claim

1. A material handling device or a hoist to lift or lower a load or to move a load from one place to another characterized in having a plurality of elements comprising i) a drive assembly (100); ii) a distance measuring tool; iii) a handle assembly (200); iv) a means of attaching a load; v) a control system, and optionally; vi) a provision to move the load in a horizontal direction; and wherein the material handling device or the hoist is capable of operating in each of the following modes, a. a handle mode; b. a float mode; c. a sequence mode wherein it is possible to perform operations of both handle and float modes without a need to select a particular mode and wherein the handle mode becomes automatically operational when no load is attached and both handle and float modes can be operated when the load is attached and wherein the handle mode can be operated without disengaging from the float mode for same load attached second or each subsequent time; wherein the handle mode is a default mode and if needed can be selected by touching a handle whereas float mode and sequence mode can be selected from the provision on the handle after attaching load without touching the load or any contact with load lifted; and wherein the material handling device or the hoist can be programmed setting multiple virtual limits to operate at multiple workstations.

2. The material handling device or the hoist in accordance with the claim 1 having i) a drive assembly (100) wherein drive assembly (100) is characterized in having a motor (101), a gear box (102), a rope drum (103) to be driven by the motor (101); ii) a distance measuring toolwherein the distance measuring tool is selected from a linear scale (104) and nut (105), a laser sensor, a magnetic strip, or encoder (106). iii) a handle assembly (200) which is characterized in having i) a housing (202); and ii) a grip (203) and comprises force / pressure sensors preferably in the form of at least two assemblies (201A, 201B) of load cells wherein the first assembly (201A) of the load cells is connected to the grip to detect the force applied on the grip of the handle assembly (200) and wherein the second assembly (20 IB) of the load cells is connected to means of attaching load.

3. The material handling device or the hoist in accordance with the claim 1 having a control system wherein the control systemis characterized in having i) one or more sensors; and ii) a control panel or PLC or microprocessor system with Human Machine Interface enclosed in an enclosure; and iii) necessary wiring or a wireless system.

4. The material handling device or the hoist in accordance with the claim 3 havingthe control system characterized in having i) one or more force sensors or one or more load sensors;and ii) one or more distance sensors or encoder (106).

5. The material handling device or the hoist in accordance with the claim 1 characterized in having a provision to move the load in a horizontal directionwherein the provision comprises plurality of components having i) a motor (101) for supplying required power for horizontally moving the load; and ii) a sensor to either detect deflection of the rope from vertical axis; or alternatively, ii) load cells or force sensor to sense the force applied by operator in horizontal direction; and wherein to sense position of the hoist in the horizontal direction on the track, said hoist is provided with an encoder (106) or track which is employed with non- contact distance sensors.

6. A mode/method of operating thematerial handling device or thehoist in accordance with the claim 1 - 4wherein the material handling device or the hoist is capable of being operated in a handle mode or a float mode or a sequence mode comprising selecting mode based on one or more of the following: i) selecting a handle mode when no load is attached or when load is attached and can be conveniently handled in a handle mode; or when lifting or lowering or moving of multiple loads of different weights is involved; ii) selecting a float mode when load is attached or when load is attached and can be conveniently handled in a float mode; or when lifting or lowering or moving of multiple loads of different weights is involved; iii) selecting a sequence mode when in any operation one may have to use both handle mode and float mode without disturbing the settings made in each mode or when lifting or lowering or moving of constant weight is involved.

7. The mode / method of operating the material handling device or the hoist in accordance with the claim 6 in a handle mode comprising i) selecting a handle mode; ii) adjusting position of the hoist by applying force on the handle to bring the means of attaching load near load; iii) attaching load to such means; iv) applying force on the handle grip (203) in either upward (push force) or downward (pull force) direction and generation of signal by load cells associated with the handle grip (203); v) receiving signals by PLC / control system wherein PLC is programmed to detect direction of desired movement. The logic used includes categorization of signals into any of the different ranges provided wherein categorization is based on the magnitude of output signal. vi)generating instruction signal by PLC /control panel wherein instruction signal provides information of the required movement (direction of movement) and speed that should be provided by drive assembly to cause lifting or lowering of the load; vii) rotating the rope drum (103) to wind or unwind the rope to lift or lower the load as per instruction signal.

8. The mode / method of operating the material handling device or the hoist in accordance with the claim 6 in a float mode comprising i) attaching load at hook / means of attaching load; ii) selecting float mode from the provision on the handle without touching the load or any contact with load lifted; iii) sensing the load as first weight by the second load cells assembly connected with the means of attaching load and generating a first signal in response to a first weight; iv) receiving signal by the PLC / control panel corresponding to the first weight and recording the first weight information about the load attached and considering it as zero load; v) applying force / pressure on load by the operator either in upward or downward direction for lifting or lowering the load; vi) sensing the force / pressure applied on the load by second load cells assembly and generating a second signal corresponding to such applied force / pressure; vii) receiving signals by the PLC / control panel and processing the signal to arrive at the desired direction of movement of load wherein the processing of signal involves comparing the signal with the first signal recorded in respect of the first weight and categorizing it into a positive or negative load based on whether the second signal is higher or lower in magnitude with respect to the first signal employing a following logic: a) comparing the second signal with first signal and if second signal is smaller than the first signal, sensing the load as a negative load or if the second signal is larger than the first signal, sensing the load as a positive load; and b) moving the load after sensing negative or positive load in a direction set by the load sensors; viii) receiving instruction signal from the PLC / control panel by the drive assembly and rotating the rope drum (103) to wind or unwind the rope to lift or lower the load as per instruction signal provided.

9. The mode / method of operating the material handling device or the hoist in accordance with the claim 6 in a sequence mode comprising i) attaching a load at means of attaching load; ii) selecting a sequence mode from the provision on the handle without touching the load or any contact with load lifted; iii) applying force on either handle or a load and generating signals by the corresponding load cell assembly and processing of the signal by the PLC / control panel to arrive at a decision about movement or non-movement of load. iv) continuing application of force on a handle or a load as per the requirement of the operation and generating signal by the corresponding same or different load cell assembly; v) receiving signals by PLC / control panel and generating instruction signals to instruct drive assembly to perform further functions; vi) Winding or unwinding of rope by the drive assembly to perform the required movement of load; vii) using the first recorded signal to perform each subsequent cycle for lifting same type of load without a need for performing the record operation for each cycle; viii) repeating steps i) and iii) to vi) for each subsequent cycle.

Description:
TITLE OF INVENTION

SWIFT HOIST AND OPERATING MODES THEROF

FIELD OF INVENTION

The invention relates to material handling devices such as a hoist that lift and lower loads as a function of force applied by operator also the hoist can move left or right on the rack with applied force.

BAKGROUND OF INVENTION

US patent US6386513B1 provides the human power amplifier assist device comprises pulley with line wound over it, an actuator to turn the pulley So as to raise and lower the line wound thereon, and an end-effector connected to the line wound on the pulley and connectable to a load. Further the end-effector comprises a handle to be held by an operator and a Sensor detecting an operator-applied force on the handle, Assist device also, comprise a controller controlling operation of the actuator, the controller being responsive to Signal from the Sensor representing operator-applied force and Signal representing tensile force on the line and the controller being programmed to cause the actuator to turn the pulley. The assist device is provided with a brake which prevents pulley from rotating at time of power failure and it also supported with dead man switch so that brake does not get engaged while operator grabbing the handle. This patent does not mention application of force by user / operator on the load. The user applies force to the end effector. While in present invention it is possible to maneuver the load by applying the force on the load instead of end effector or handle.

The patent US20070205405A1 owned by Gorbel discloses lift system comprising controller for controlling actuator having drive mechanism and load interface connected to farther end of the rope including user controls and generating signals to be transmitted to said controller to operate actuator. System also comprises travel sensor for sensing the position of the sliding gate from which free end of rope leaves pully to maintain registration of the rotation of pully. System further comprises operator interface a having handle having provision to rotate 360 ° with respect to rope handle further comprise sensors for sensing the load applied by user on handle and LCD to show the status of the system. Controller of the system has logic circuit composed of electromechanical or solid-state relays, Switches and sensors to start and stop the system in response to a sequence of possible events. Patent also comprises communication system for remote operation.

In patent US 20030025110A1 lifting device and a method for lifting by using that same device is provided. Device is claimed to move an object in any direction such as vertical as well as horizontal with minimum efforts applied, which is superior to Gorbel device which can only move in vertical direction. This patent does not claim different modes of operations.

The present invention provides the swift hoist having different modes of operation, having variable speed depending on force applied by operator on the handle as well as load attached/component.

OBJECT OF INVENTION

First object of the invention is to provide a material handling device or a swift hoist to lift and lower a load or to move a load from one place to another.

Second object of the invention is to provide a swift hoist with different operating modes with a provision of variable speeds to suit lifting / moving of different loads.

Third object of the invention is to provide a material handling device or a hoist capable of picking load from and dropping load at different heights in a manual operation mode as well as in a manual operation assisted by set program mode.

Another object of the invention is to provide a material handling device or a hoist with different load attachments to lift different types of loads enabling precise movement of loads particularly for assembly.

SUMMERY OF INVENTION

Under the first aspect, the present invention provides a material handling device or a hoist to lift and lower a load or to move a load from one place to another. Herein after, the device is termed as swift hoist. The swift hoist comprises i) a drive assembly; ii) linear scale; iii) a handle assembly; iv) a means of attaching load; and v) a control system.

The second aspect of the invention is to provide a swift hoist with different operating modes with a provision of variable speeds. First mode is a handle mode in which user/ operator applies force / pressure on the handle and according to the direction of the force, hoist lifts or lowers the load. The handle mode is a preferred mode for all loads and hence set as a default mode. Second mode is a float mode in which user applies the force / pressure on the load lifted or load attached instead of a handle and according to the application of force by the user / operator, hoist lifts or lowers the load. The float mode is preferred when it is necessary to touch the load for controlling the movement and proper positioning of the load. Since this is not a default mode, the system needs to be put into the float mode whenever required. Third mode is a sequence mode in which it is possible to perform operations of both handle and float modes without selecting a particular mode from the provisions provided. In a sequence mode, swift hoist can be operated either by touching a handle or by touching a load. This mode is preferred where the same load (weight component) is moved / lifted /lowered repetitively. Hence, it is not required to put hoist in a float mode. It automatically detects presence or absence of weight / load and automatically follows float mode or handle mode operations.

The third aspect of the invention is to provide a swift hoist with different functionalities to make it suitable to work in various assembly lines or in various standalone operations. For example, swift hoist finds numerous applications in material handling, industrial lifting, construction activities and loading and unloading materials on pallets.

The functionalities comprise providing virtual limits in a vertical and optionally in a horizontal direction to define as specified area of operation. This is often helpful when availability of workplace is a constraint. This is also helpful for optimum area / space utilization. With this functionality, it is possible to provide different virtual limits for different workstations. BRIEF DESCRIPTION OF DRAWING

Figure 1 provides swift hoist (arm) manipulator type.

Figure 2 provides swift hoist ceiling manipulator type.

Figure 3 provides swift hoist gantry system. Figure 4A provides drive assembly and figures 4B and 4C provide components of drive assembly of the swift hoist.

Figure 5 provides components of handle assembly of the swift hoist.

Figure 6 provides the assembly line with multiple workstation having different virtual limits. Figure 7 provides drive assembly 100 shoving the components of drive assembly of the one of the embodiments of present invention which have encoder 106 instead of line linear scale 104 and a nut 105.

DETAILED DESCRIPTION OF THE INVENTION

A Swift hoist is modem equipment which works on Actuator (servo- based/pneumatic / hydraulic system). There are many advantages of Swift hoist system over chain blocks (electric chain hoist), rope hoist and pneumatic hoist.

Swift hoist of the present invention requires less effort to maneuver load than the conventional lifting systems. Swift hoist is fast, smooth, easy to handle and enables individual to lift and lower or move a load with minimal strain on the body and has precise control with variable speed according to force in all operations it performs. Thus, the swift hoist increases efficiency of the operator and operations. This hoist can be widely used in many different types of industries where material handling is needed in large quantity and can be widely used where material must be precisely handled like assembly work etc.

In a simplest form, the swift hoist can lift a load of up to 50 kg and preferably up to 100 kg. By further enhancing load carrying capacity of a drive assembly, the swift hoist of the present invention can lift / move around 500 kg load.

Under the first aspect, present invention provides a material handling device or a swift hoist to lift or lower or to move a load from one place to another with the help of a track or light weight crane or manipulator or any other system specially designed according to application. The swift hoist comprises plurality of elements comprising i) a drive assembly; ii) a distance measuring tool iii) a handle assembly; iv) a means of attaching load; and v) a control system, and optionally vi) a provision to move the load in a horizontal direction.

Drive assembly:

The drive assembly comprises a motor, preferably, a servo motor with a gear box for speed reduction for providing required torque to manoeuvre load. The gear reduction may include planetary gear mechanism for speed reduction or to generate required torque. Drive assembly further comprises a rope drum / screw driven by the motor through a gear reduction mechanism. Alternatively, the rope drum can be directly driven by motor without any intermediate transmission. A rope or a cable is made up of Carbon fibre or steel or nylon. At one end, the rope is attached to the drum and at the other end, it is free to connect to a means of attaching load through handle assembly. The drum is rotated by a motor to wind or unwind the rope to lift or lower the load as per the force applied by the operator.

In an embodiment, a drive assembly comprises a servomotor of 0.750 KW capacity which rotates rope drum through a planetary gearbox to generate necessary torque. A steel rope dia. 6mmhas its one end attached to a hook and the other end attached to the rope drum to wind and unwind on the drum as the drum rotates.

Distance measuring tool

Linear scale and nut or distance sensor:

Linear scale (other measuring devices can also be used like laser sensor, magnetic strip oer encoder etc) is a rod with a scale on it. It sets a travelling limit of the hoist. It is placed along with the drive assembly. A nut is provided on the drum which slides on the drum and on the linear scale as the drum rotates. Sliding of the nut on the linear scale can be detected by any means such as optical, magnetic, capacitive, inductive or resistive type. Thus, sliding of the nut is measured by linear scale which further determines how much of the rope is wound or unwound using an arithmetic equation. Thus, the two extreme positions of the nut on the linear scale set travelling limit of the hoist. Continuous measurement of the position of load in a vertical direction in turn helps to provide the exact location of load and its future movement at any time. Linear scale helps to set virtual limits for the swift hoist.

As an alternative to linear scale and nut, suitable distance sensors can be employed. Also, as an alternative, other measuring device can also be used like laser sensor magnetic strip or encoder etc.

Handle assembly:

Handle assembly comprises) a housing and ii) a grip. The housing is located at the top end of the handle assembly and it encloses one or more sensors which are components of the control system. Load cells are preferred sensors. Preferably two separate assemblies of load cells are enclosed in the housing in such a way that they are mechanically isolated. Housing protects the load cell assemblies from the external intervention.

Housing also has a provision to select different modes of operations. The provision is in the form of one of more of a push button, a toggle switch, a touch screen display or any other suitable structure. The lower end of the handle is an ergonomically designed grip to hold it in a hand easily. The grip is a hollow rod which is connected with only one load cell assembly but not connected with the other load cell assembly. The load cell assembly attached to the grip is employed during handle mode operation. The lower end of the handle is connected to a means of attaching load. During operation of the swift hoist, the force /pressure applied by the operator on the handle is sensed by the load cell assembly attached to the grip.

In a preferred embodiment handle assembly encloses two load cell assemblies, one is connected to the handle grip to detect force on the handle grip and the other assembly is secured to housing and means of attaching load which is used to detect weight of the load attached and forced applied to the load. Both assemblies are mechanically isolated from each other to avoid false trigger.

A means of attaching load- Another feature of the present invention is to have customized load attachment. For example, the hook or means of attachment to which load is attached may comprise different types of hooks, sometimes hook may be replaced by clamps or suction cups/points or grippers or toggle clamps and similar means. Some magnetic picking devices can be used for magnetic materials. Large objects can be grabbed by ropes and then tied to hook.

Hooking point or means of attaching load is customised as per the size and shape of the load and /or weight of the load. Hooking point changes with the application and operating conditions. Multi-functional hooks can be provided for attaching the loads.

Control System

The control system comprises i) one or more sensors and ii) a control panel or PLC or microprocessor system with Human Machine Interface enclosed in an enclosure and iii) necessary wiring or wireless system. Alternatively, wireless control system can also be employed.

The control system also referred as a Controller (PLC or control circuit) is a brain of the swift hoist which is responsible for all the operations performed by the swift hoist. The control system comprises force sensors or load sensors and may further comprises one or more distance sensors or encoder. The control system preferably comprises i) one or more force sensors or one or more load sensors; and ii) one or more distance sensors or encoder.

The position of sensors may vary as per requirement of operation. The sensors may be present in the handle and/or in the vicinity of rope and/or in the drive assembly. In a preferred embodiment, force or load cell are present in a housing of the handle assembly.

Sensors are connected to programmable logic circuits (PLCs)/control panel. During operation, sensors are activated to generate signals. The control panel / PLC is equipped with a microcontroller/CPU to process the signal received from the sensor as per the program stored in the memory. Further control panel generates instruction signal which is further transmitted to drive assembly to produce necessary action. The instruction signal comprises the information about the tension to be produced in the rope/ cable to lift the load and direction in which drum to be rotated.

Control panel controls both direction and speed of the movements of the swift hoist according to the force/pressure applied by the operator/ user on the handle or the load.

Control panel provides a user interface (HMI) which enables the user to control the operations of hoist. The interface is enclosed in an enclosure. In an embodiment, a Human Machine Interface (HMI) is enclosed in IP-65 Panel. Controlling operation of the hoist may comprise defining speed limits, operating range, and adding some additional functions according to the requirement of the end user.

Another use of the control panel is to set a program for multi-station pick up or drop of load in an assembly line. Alternatively, the data can be set through HMI. During such operations, the control panel allows setting of virtual limits beyond which load movement does not take place. For example, if at a specific position in an assembly line, virtual limit for load drop is set as 1 meter, the load at this specific location will not move when the distance reaches 1 meter from the ground or any point set manually.

In an embodiment the swift hoist is employed with servo motor to drive the drum through planetary gear box so that it can produces necessary torque to lift a load attached to the hook. Hook is connected to the handle assembly which is attached to the free end of rope wounded on the drum. Capacity of lifting may vary from 100-500kg and can be increased further. The speed of lifting or lowering of a load may range from 0 to 40 meters per minute and can be increased further as per the requirement. Speed may be defined in terms of RPM of the motor. The speed of handle mode and float mode can be set differently.

In an embodiment, the speed of lifting or lowering is 0-35 meters per minute. In one more embodiment, the speed is 0-20 meters per minute. In yet another embodiment, the speed is 0-10 meters per minute.

There is no limit to how many times or how many settings of virtual limits are done in a single program. Thus, the swift hoist of the present invention can be used in an assembly line with multiple workstations with different lifting and dropping heights.

In an embodiment, maximum height up to which load is lifted is about 1 - 1.5 meters from the ground. In another embodiment, maximum height up to which load is lifted is about 1.5 - 2 meters from the ground. In yet another embodiment, maximum height up to which load is lifted is about 2 - 2.5 meters from the ground and can be extended as per requirement.

Load cells sense the force applied by the operator as well as weight of the load lifted. PLC is used to process the signals. For ensuring the safety of the swift hoist CE certified electrical connections are preferred. The swift hoist additionally may have a provision to move the load in a horizontal direction. The provision comprises plurality of components having i) a motor for supplying required power for horizontally moving the load; and ii) a sensor to either detect deflection of the rope from vertical axis; or alternatively, ii) load cells or force sensor to sense the force applied by operator in horizontal direction; and further to sense position of the hoist in the horizontal direction on the track, said hoist is provided with an encoder or track which is employed with non- contact distance sensors.

This provision may comprise an associated system such as housing with rollers to guide the drive assembly over a track / guide rail. The track or guide rails may be temporarily or permanently attached to the roof preferably through a support. Alternatively, hoist is attached with light crane / Light Rail Cranes. The housing with rollers may be driven by operator’s pull or by motor.

Moving heavy weights in a horizontal direction for an ordinary human is very cumbersome. Further, controlling the motion of such heavy weight by simple pushing or pulling over the track is quite difficult and unsafe. The present invention also provides a system with a facility to control the horizontal motion of the load over the track. The system comprises an additional motor for supplying required power for horizontally moving the load. The system further comprises a sensor, preferably a fork sensor to either detect deflection of the rope from vertical axis or alternatively, the system comprises a load cells or force sensor to sense the force applied by operator in horizontal direction. To sense position of the hoist in the horizontal direction on the track, hoist is provided with an encoder or track is employed with non-contact distance sensors. The horizontal motion can be only horizontal or diagonal (both horizontal and vertical). In any of these motions, load moves from a first position to at least second new position. The virtual limits for second and subsequent new positions can be set with respect to any reference position. When load is moved to a position for which virtual control limits are set, it can’t be moved further and thus the load can be unloaded at a precise position. In a horizontal assembly line having multiple workstations, the workstations might be at the same heights or at multiple heights. Accordingly, the horizontal motion can be precisely controlled by setting appropriate virtual limits for vertical and horizontal positions of the load (i.e. multiple virtual limits can be set at different station). At a single workstation for fitting multiple parts, multiple virtual limits can be set in sequence. In an embodiment, fitting of frame, engine and battery at a single workstation is accomplished by setting different virtual limits in sequence to suit fitting of first frame then engine and then battery.

Alternative to or in addition to housing with rollers and corresponding track and support, swift hoist is often attached, connected or associated with an associated system having arm or manipulator which moves on the support track to cause horizontal motion of the load.

In an embodiment the swift hoist is associated with a manipulator with a track and the hoist moves on a track to cause horizontal motion of the load. In another embodiment the swift hoist of the present invention is attached to an arm which moves on the support track to cause horizontal motion of the load.

When operator wants to move the load in a horizontal direction, the operator will either push or pull the load suspended / lifted by hoist in a horizontal direction. The sensors preferably load cells sense the applied force and generate signal which are received by the control system / PLC to further generate instruction signals to enable motor to provide the required force to move the load horizontally to reduce human efforts. Alternatively, if fork sensor is installed, it senses the deflection of the rope caused and generates signal to enable motor to provide the required force to move the load horizontally and reduces human efforts.

The load may be lifted vertically by applying a first / vertical force and then moved horizontally by applying a second/ horizontal force. The action of lifting, lowering or moving of load is accompanied by application of force or pressure. Lifting and lowering of the load is accomplished by means of the swift hoist alone whereas moving load in a horizontal direction is additionally accomplished by the associated system. Thus, any movement of load happens as long as force or pressure is applied and thereafter the movement stops. The speed of movement of load thus depends on magnitude of force or pressure applied.

Figures 1 - 3 provide various arrangements of the swift hoist that can be used for horizontal movement alone or for horizontal movement along with vertical movement.

Figure 1 provides swift hoist manipulator (arm) type400. In this arrangement hoist can move horizontally along the arm. Load 700 is attached at the hook / means of attaching load 300. User or operator can hold a handle assembly 200 or a load 700 to move it horizontally. Drive assembly 100 slides on the manipulator arm.

Figure 2 provides swift hoist ceiling manipulator type500. In this type, ceiling has the guides for moving the hoist in lateral directions which is very useful for assembly lines.

Figure 3 provides swift hoist gantry system600. This system is used when heavy loads need to be lifted and moved horizontally.

Figure 4 A provides drive assembly 100 and figures 4B and 4C provide components of drive assembly of the one of the embodiments of present invention and a linear scalel04 and a nut 105. Drive assembly components shown comprise i) rope drum 103 which can be driven by ii) motor 101 through iii) gear reduction mechanism 102. The rotation of the rope drum causes winding or unwinding of the rope whose one end is fixed to the drum and the other end is connected to the load via means of attaching load.

On rotation of the drum, the nut slides through certain distance on the linear scale which can be detected by any means such as optical, magnetic, capacitive, inductive or resistive type. Thus, sliding is measured by linear scale which further determines how much of the rope is wound or unwound using an arithmetic equation.

Figure 7 provides drive assembly 100 shoving the components of drive assembly of the one of the embodiments of present invention which have encoder 106 instead of line linear scale 104 and a nut 105. Figure 5 provides components of handle assembly 200 of one of the embodiments of the swift hoist of present invention. A cylindrical part is a handle grip 203. A housing 202is enclosing two load cell assemblies (201A, 201B). A first load cell assembly (201A) is used to sense the amount of force applied by the user on the handle grip and second Load assembly (20 IB) is used to sense the amount of force applied on the load. Figure 5 also provides the rod 204 as a connecting means between the second load cell assembly 20 IB and the load.

The second aspect of invention is to provide swift hoist with different operating modes with a provision of variable speed to maneuver the load with ease. First mode is a handle mode in which user/ operator applies force / pressure on the handle and according to the direction of the force, hoist lifts or lowers the load. This is a default mode. Second mode is a float mode in which user applies the force / pressure on the load instead of a handle, and according to the nature of application of force by the user / operator, hoist lifts or lowers the load. Further, the swift hoist of the present invention is characterized by yet another mode of operation which is a sequence mode. In a sequence mode, swift hoist can be operated either by touching a handle or by touching a load. Thus, the swift hoist can perform operations of both the modes without selecting any specific mode. This mode is preferred where the same load (weight component) is moved / lifted /lowered repetitively when one need not select float mode again and again to move the same / similar load to save time and enhance operation efficiency. Hence, it is not required to put hoist in a float mode. It automatically detects presence or absence of weight / load and automatically follows float mode or handle mode operations.

Selecting a mode is based on one or more of the following: i) a handle mode is selected when no load is attached or when load is attached and can be conveniently handled in a handle mode; or when lifting or lowering or moving of multiple loads of different weights is involved; ii) a float mode is selected when load is attached or when load is attached and can be conveniently handled in a float mode; or when lifting or lowering or moving of multiple loads of different weights is involved; iii) a sequence mode is selected when in any operation one may have to use both handle mode and float mode without disturbing the settings made in each mode or when lifting or lowering or moving of constant weight is involved.

Handle mode

Handle mode is a default mode of operation of swift hoist. It can get selected if needed by touching handle.

Handle assembly comprises force / pressure sensors preferably in the form of at least two assemblies of load cells. First assembly of the load cells is connected to the grip and it detects the force applied on the grip of the handle assembly. The second assembly of the load cells is connected to means of attaching load. Once the load is attached on the hook, the load cells of the second assembly sense the weight of the load. Both the load cells assemblies are mechanically isolated from each other and other components of handle assembly so that forces applied accidently on the other parts do not interfere with the signal generated by any load cell assembly.

Force sensor / pressure sensor /Load cells sensor senses the pressure / force applied by the operator on the handle grip. Load cells generate signals corresponding to the force applied. The direction of applied force is detected through the push or pull force sensed by the load cells which determines the direction of lifting or lowering of load. The load cell assembly associated with the handle grip is unique load cell assembly in that it works as bilateral load cells assembly. In each load cells assembly, there is a provision to detect both compressive force and tensile force of small magnitude in addition to its ability to detect either compressive force or tensile force of any magnitude. The load cells can generate signals corresponding to this detected small magnitude force. By calibrating this signal, it is possible to detect direction of applied force whether compressive or tensile i.e. whether the direction is upwards or downwards. For example, in a compressive load cells, the cells can sense small magnitude tensile force in addition to sensing compressive force over large range. If handle grip of the hoist is pulled down, no compressive force is sensed but a small magnitude tensile force is sensed by the load cells. This leads to generation of signal. The PLC circuit (control panel) processes signals received from sensors / load cells and further calculates the amount of effort / force required to be provided by the (swift hoist) drive assembly to lift (maneuver) or lower the load and produces instruction signals which instruct drive assembly to produce necessary action.Further drive assembly rotates the drum to wind or unwind the rope at speed proportional to the force applied to cause lifting or lowering of the load.

If force/pressure applied by the operator is in upward direction hoist will move upward by winding the rope on the drum and if applied force is in downward direction hoist will move down by unwinding the rope. In the handle mode if no pressure / force is applied on the handle, hoist will remain stationary.

The lifting or maneuvering speed is proportional to the pressure /force applied on the grip of the handle by the operator. Operator / user can achieve variable speed and higher position accuracy by applying proper pressure/force on the handle. This is very useful for precise handling of the load without much efforts.

Method of operating swift hoist of the present invention in a handle mode comprises following steps i. Adjusting position of hoist by applying force on handle to bring the hook near load; ii. Attaching load at hook / at means of attaching load; iii. Applying force by user on the handle grip in either upward (push force) or downward (pull force) direction and generation of signal by load cells associated with the handle grip; iv. Receiving signals by PLC / control system wherein PLC is programmed to detect direction of desired movement. The logic used includes categorization of signals into any of the different ranges provided wherein categorization is based on the magnitude of output signal. v. generating instruction signal by PLC /control panel wherein instruction signal provides information of the required movement (direction of movement) and speed that should be provided by drive assembly to cause lifting or lowering of the load; vi. rotating the rope drum to wind or unwind the rope to lift or lower the load as per instruction signal; wherein speed of lifting or lowering is proportional to the force applied on the grip; and wherein only those signals generated by load cell assembly associated with the handle mode i.e. load cell connected to the handle grip are taken into consideration. For generating instruction signals by the PLC.

Float mode

Swift hoist has another mode of operation which is a float mode. Additional (second) load cells assembly is enclosed in the same handle assembly so that swift hoist can be operated in a float mode. Main difference between the handle mode and the float mode is that in the handle mode pressure / force is applied to the handle whereas in the float mode pressure / force is applied to the load attached without touching the handle.

Housing of handle assembly has a provision to select different modes of operations from where float mode can be selected. The provision is in the form of one of more of a push button, a toggle switch, a touch screen display or any other suitable structure.

First a load is attached at the hook and then the float mode is selected from the provisions provided within the handle assembly. Force / pressure sensors (Load cells) associated with float mode senses the load attached. This is the first weight sensed by the second load cells assembly after the swift hoist is put in the float mode. Load cells assembly sends signal corresponding to the first weight sensed. The PLC / control panel receives the signal corresponding to the first weight and records the first weight information about the load attached. In a float mode operator applies the pressure /force on the load attached. This applied pressure /force is either for lifting or lowering of the load. This force / pressure is sensed by second load cells assembly which generates corresponding signal which is received by the PLC / control panel. The PLC / control panel generates instruction signals for the drive assembly based on the signal provided by load cell assembly. The drive assembly lifts or lowers the load by winding or unwinding of rope according to instructions received from the PLC /control panel. The swift hoist moves upward or downward as per the force sensed by the load cell assembly associated with float mode. Speed of moving the load is proportional to the pressure /force applied on the load by the user. Float mode is deactivated / disables as soon as handle is used.

Method of operating swift hoist in a float mode comprises following steps: i) attaching load at hook / means of attaching load; ii) selecting float mode from the provision on the handle without touching the load or any contact with load lifted; iii) sensing the load as first weight by the second load cells assembly connected with the means of attaching load and generating a first signal in response to a first weight; iv) receiving signal by the PLC / control panel corresponding to the first weight and recording the first weight information about the load attached and considering it as zero load; v) applying force / pressure on load by the operator either in upward or downward direction for lifting or lowering the load; vi) sensing the force / pressure applied on the load by second load cells assembly and generating a second signal corresponding to such applied force / pressure; vii) receiving signals by the PLC / control panel and processing the signal to arrive at the desired direction of movement of load wherein the processing of signal involves comparing the signal with the first signal recorded in respect of the first weight and categorizing it into a positive or negative load based on whether the second signal is higher or lower in magnitude with respect to the first signal employing a following logic: a) comparing the second signal with first signal and if second signal is smaller than the first signal, sensing the load as a negative load or if the second signal is larger than the first signal, sensing the load as a positive load; and b) moving the load after sensing negative or positive load in a direction set by the load sensors; viii) receiving instruction signal from the PLC / control panel by the drive assembly and rotating the rope drum to wind or unwind the rope to lift or lower the load as per instruction signal provided; wherein only those signals generated by load cell assembly associated with the float mode i.e. load cell secured to the housing and connected to the means of attaching load /hook are taken into consideration; and wherein further, speed of the movement of load (speed of lifting or lowering) is proportional to the force applied by operator on the load; wherein float mode disables as soon as handle is used. It is because the program is designed such that as load cell assembly associated with handle grip generates signal handle mode is prioritised (handle mode overrides the float mode.)

Sequence mode

In the sequence mode it is possible to shift operations of a handle or a float mode into the other mode (float or handle mode) without selecting any mode from the provisions provided. In a sequence mode, swift hoist can be used to perform operation in a handle or float mode merely by applying force on a handle or a load. The handle mode becomes automatically operational when no load is attached and float mode is not disabled / deactivated / disengaged when handle is used. The handle mode can be operated without disengaging from the float mode for same load attached second or each subsequent time. This mode is preferred for assembly lines to lift similar components / load having same weight where speed is more and when there is no time to put the swift hoist in the float mode again and again. In a preferred embodiment, for activating sequence mode, first the load is attached to the hook and then float mode is selected from the provisions provided in a handle assembly without touching the load attached. Once the system is in a float mode, the sequence mode is selected from the provisions provided in a handle assembly by selecting any of the push button, touch screen display or any other means etc. Alternatively, operator/user can select sequence mode directly without first selecting float mode.

Once the sequence mode is activated, operator/ user can lift the load by using handle and can perform operations in the float mode by applying force / pressure on the load attached. Thus, it is possible to simultaneously operate the swift hoist in handle and float modes for optimum operation efficiency. In the sequence mode, signals generated by both load cell assemblies are taken into consideration for producing instruction signal by the PLC.

Method of operating swift hoist in a sequence mode comprises following steps i) attaching a load at means of attaching load; ii) selecting a sequence mode from the provision on the handle without touching the load or any contact with load lifted; iii) applying force on either handle or a load and generating signals by the corresponding load cell assembly and processing of the signal by the PLC / control panel to arrive at a decision about movement or non-movement of load. iv) continuing application of force on a handle or a load as per the requirement of the operation and generating signal by the corresponding same or different load cell assembly; v) receiving signals by PLC / control panel and generating instruction signals to instruct drive assembly to perform further functions; vi) Winding or unwinding of rope by the drive assembly to perform the required movement of load; vii) using the first recorded signal to perform each subsequent cycle for lifting same type of load without a need for performing the record operation for each cycle; viii) repeating steps i) and iii) to vi) for each subsequent cycle. wherein speed of the movement is proportional to the force applied by operator on the handle assembly (handle grip) or load lifted.

PLC receives signals from both the load cells assemblies associated with the handle and load and then decides which mode to choose for further actions. In this operation, different methods can be employed.

In a first method, handle operations are prioritized such that when signals are received from both the load cells assemblies, PLC generates instruction signals based on signals from load cell assembly associated with handle.

In a second method, PLC / control panel compares the signals generated by both load cells assemblies associated with the handle and load to determine which signal is bigger to generate instruction signals. In this method, force applied on handle is taken as it is whereas force applied on load is compared with the weight of the load. For example, if 5 kg of force is applied on the handle, 5 kg of force is directly recorded. However, if for a load of 20 kg, 5 kg of force is applied, total force become 25 kg from which weight of load 20 kg is subtracted so that the force on load of 5 kg is considered. Now, if the load is lifted with a force of 5 kg, total force become 15 kg from which actual weight of load of 20 kg is subtracted so that the force on load of -5 kg is considered and the load is lifted up. In this method PLC simultaneously and continuously checks for both handle and float mode signals to decide which modes to be followed.

The third aspect of the invention is to provide a swift hoist with different functionalities to make it suitable to work in various assembly lines or in various standalone operations. For example, swift hoist finds numerous applications in material handling, industrial lifting, construction activities and loading and unloading materials on pallets. The functionalities provide virtual limits in the vertical and horizontal direction to define the specified range of operation by considering availability of workplace. Virtual limits are the limits on the distance to be travelled by the hoist. The upper and lower limits for travelling of hoist can be set. For example, in an embodiment for a hoist operated in a vertical direction virtual limits of ground 2 feet - 6 feet means that the hoist can move the load in space from 2 feet from the bottom to 6 feet from the bottom. In another embodiment, hoist is to be operated from left to right such that load is to be moved from 2 feet above the ground to 6 feet above the ground through a horizontal distance of 5 feet. This is done by providing multiple virtual limits along the 5 feet distance. The load can be moved in the following multiple ways, a. 0.8 foot vertical per each lfoot horizontal b 2 feet vertical per first 2 feet horizontal and 2 feet vertical for next 3 feet horizontal c. 3 feet vertical per first 2 feet horizontal and 1 foot vertical for next 2 feet horizontal d. 1 foot vertical for first 1 foot horizontal, 2 feet vertical per 3 feet horizontal and 1 more foot vertical per 1 foot horizontal. e. several other combinations are possible.

Thus, it is possible to provide different virtual limits based on space availability and other considerations such availability of resources.

In a complex operation, it is possible to set different virtual limits for multiple workstations. When a single hoist is used to lift and lower the load along the assembly path i.e. in case when hoist is used to lift the load from one work-station and lower it to other work-station having different elevations, then hoist should be provided with multiple virtual limits in vertical direction along the path from the reference point and according to availability of the space.

The present invention provides such provision to set and record multiple virtual limits in vertical direction as per the position of hoist along the path. This makes operation of the hoist safer and precise. Also, it is possible to change the virtual limits as per the need of the operation. To achieve multiple virtual limits at different locations along the path, a proxy system comprising encoder linear scale or distance laser sensor or a system which provides a distance measurement can be employed. Different systems are programmed so that swift hoist can be used at different stations or different locations with one or more virtual limits. With multiple virtual limits, it is possible to move the load along the assembly line at different height of elevation as per limits stored in program. Virtual limits restrict the motion of the load within the set limits even if user applies force to pull or push load beyond already set limits.

Virtual limits for operation of handle mode and virtual limit for operation of float mode can be different. This may become necessary for compensating the positional difference between the handle and lower end of the load.

Process for setting the virtual limits at different location.

Two methods can be adopted.

First method is as follows: i) While operating in handle mode, bring the hoist at a position for which higher or lower virtual limits are to be set; ii) Take hoist to a lower position which is to be set as lowest virtual limit and save corresponding reading measured as distance from the ground in the memory. Similarly raise hoist to a height which is to be set as upper virtual limit and save corresponding reading measured as distance from the ground in the memory. iii) Move forward to the next workstation and follow the same procedure which will record the lower and upper vertical limits for that location.

Second method is as follows: i) instead of bringing hoist to a particular position, one can select sequence of workstation in the program such as first workstation or second workstation and enter and save values for upper and lower virtual limits for that workstation.

It is possible to set same or different virtual limits for different modes. This feature is very useful in an assembly line. For the operations in the sequence mode, there is no need to set virtual limits again, the virtual limits as set in the handle and float mode can be accessed and used in same manner as described above.

To change virtual limit at any location, user or operator can first erase the recorded data or override the new virtual limits.

As provided in figure 6, hoist moves from first workstation 1 having virtual limits of 0.6m to a fourth workstation 4 having virtual limit of 0.4 m along the path. Workstations 2 and 3 have virtual limits of 1 m and 1.2 m respectively. All limits set are lower limits and calculated from the ground. The position of hoist along the path is detected by laser sensors attached to the track, and as the hoist reaches a particular station having virtual limits, the motion of the load is restricted within the set virtual limits associated with that station.

The load can travel through a curved path in vertical plane by proper setting of virtual limits which does not require lifting or lowering but by simply pushing the load. The load will follow the curved path as per the virtual limits provided

It is possible to carry out multi-step operation at a single workstation which may require to set different vertical limits for each step. These different virtual limits can be set in a sequence at that workstation for ease of operation. Multiple limits can be programmed in sequence if one hoist is used to place different parts on single station (for example same hoist is used to first put frame then put engine and then the battery etc.)

Additionally, the swift hoist of the present invention has automatic travel or auto travel feature. Thus, it can also travel automatically from one station to other if path is provided in the program. This is preferred when path is long. For example, if operator picks load from 1 workstation it will travel automatically to other workstation as programmed without human efforts/force. To enable this, additional sensors and additional drive assembly can be employed.

Swift hoist of the present invention has safety features in the operations of various modes. For example, in a float mode when load is unloaded and when sensors sense at least certain % of reduction in load, hoist stops moving. Handle is used to operate the hoist in such situations.

Additionally, each hoist has mechanical limits beyond which the hoist cannot move even if virtual limits are set beyond the mechanical limits.

Speed limits

The speed of lifting or lowering of load is proportional to the force / pressure applied by the user or operator. However, the present swift hoist has a provision to set speed limits beyond which speed of lifting or lowering of a load cannot go even if excessive force or pressure is applied by the user / operator. This can be achieved by the customized programmable logic. Operating speed limits can be displayed on HMI and a provision to select a certain speed through HMI is possible. In an embodiment, for small loads up to 20kg, speed limit can be kept as 0 to 40m/min or 0 - 500 RPM of motor / 0 - 50 RPM rope drum. In another embodiment for heavy loads such as up to 500kg, the speed limit can be selected as 0 to 5 m/min or 0 - 100 RPM of motor / 0 - 10 RPM of rope drum. Range is provided within which the speed varies as per the force applied by the user / operator. The speed of different mode can be set differently.

Speed of lifting or lowering or moving a load can be set within the provided speed limit range according to i) weight of load, ii) the nature of operation iii) mode of operation (generally handle mode has higher speed limits than float mode) etc. Thus, it is possible to set different speed limits at various workstations along with setting of different virtual limits at those workstations.

Load will not move unless some minimum force is applied. This minimum force is preferably 0.2 kg (for a handle mode) or 0.25 kg - 0.5 kg for a float mode). If small force is applied, load will move at slow speed and if high force is applied, load will move faster. Maximum force is preferably up to 10 kg (for a handle mode) or 10 - 20 kg for the float mode.

Another feature of present invention is wireless operation which allows the operator to move the load without physically touching the load or hoist. This is achieved by various methods. One of the preferred methods is hand movement sensing. This remote operation is performed by operator using a hand glove. Hand glove will have sensors which will be detected by infrared detector placed on the hoist. Alternatively, human movement is detected by camera system attached to the hoist. The recognized movement is processed to generate required instruction signal for moving the load.

Another feature of the present invention is to have customized load attachment. For example, the hook or means of attachment to which load is attached may comprise different types of hooks, sometimes hook may be replaced by clamps or suction cups/points or grippers and similar means. Some magnetic picking devices can be used for magnetic materials. Large objects can be grabbed by ropes and then tied to hook.

Process of setting limits for swift hoist operation

The upper and the lower limits of the swift hoist can be set by operator to define the range of operation of the hoist. This is achieved by employing a linear scale in the system. A graduated linear scale of certain dimension is fitted in the vicinity of rope drum. A nut slides simultaneously on the rope drum and the linear scale. The travelling of certain distance by sliding of nut on the linear scale correlates to certain rotations of drum. An arithmetic equation provides the number of rotations of the drum and length of rope wound or unwound. The total length of the rope is fixed in each hoist. Hence, it is possible to correlate from the distance travelled by sliding of nut, the rope wound or unwound and hence position of the load. When nut reaches at any extreme position on the linear scale, the rope is either wound or unwound to maximum extent. Thus, the two-extreme positions of the nut on the linear scale provide the travel limit (maximum operating range of that particular hoist).

Applications of the said swift hoist

• Industrial lifting application.

• Pick and place application. • Assembly line.

• Automation assembly purpose.

• Machine assembly with various components.

• Material handling. · Construction areas.

• Loading and unloading components on machine like VMC, CNC Lathe Surface grinding machines.

• Loading and unloading material on pallets. Hence less consumption of time.

Table 1 provides the specifications of swift hoist such as a weight-lifting capacity of different embodiments of swift hoist according to the present invention along with its maximum operating height and speed ranges. These are provided for better understanding of the invention and do not limit scope of the invention in any way.

Tablel: swift hoist specifications