CA2773839A1 - A multipurpose manipulator - Google Patents

Abstract

This Patent application is for a Multipurpose Manipulator which can duplicate and exceed the abilities of the human hand, as well as being able to mimic the versatility of an octopus tentacle.
Many current designs are limited to simple "open and close" movements in only one plane of motion. This proposed design is an improvement on conventional manipulators as it allows for many planes of movement, as well as superior and controllable gripping strength.
The basic design involves a series of rotatable, circular inclined planes enclosed in a flexible outer covering. Small electromagnets spin the circular "wedges" into different configurations, thus producing a powerful bending motion. A central cable temporarily "locks in"
the configuration.
The "Multipurpose Manipulator" is easily scaled up or down in size and the strength and speed of motion can be predesigned into the unit. It is well suited for such things as enhanced prosthetics, remotely controlled equipment, medical probes and construction equipment, particularly those involved in picking up, moving and releasing objects. lt is well suited for robotic assembly line work.

Description

SPECIFICATION
This invention is an improvement on existing types of manipulators found in mechanical devices.
Currently, present day prosthetics and remote manipulators usually work only in one plane of movement at a time, with a simple "open or close" movement. Their capability to manipulate complex shapes is limited and their ability to grip an object is dependent on small areas of contact.
Present day prosthetic hands, for example, do not come close to mimicking the versatility of the human hand.
Robotic "hands" on everything from deep water remotely operated vehicles to assembly line work are limited in their ability to use tools and they often require that assembly parts must be presented in a particular and often precise orientation. The ability of heavy earth moving machinery to pick up a large rock and place it precisely in a truck is more a test of how the operator can overcome the limitations of the equipment than anything else.
Many of these limitations can be overcome by utilizing this new design that is much more flexible, controllable, versatile and powerful than existing manipulators. At its most basic level, the manipulator consists of two types of discs which operate in pairs. One disc (Figure 1.1) is flat with a series of electromagnets (a) embedded in it.

The disc itself is firmly attached to a central semi-flexible tube (e). Wires controlling the electromagnets are routed down the inside of the tube to a controller, which will act as an interface between the operator and the manipulator.
The bottom side of this disc has a layer of magnetically impermeable material (g) to prevent interference with the discs below it.
The second type of disc (Figure 1.3) consists of a disc with a raised upper surface as seen in cross section in Figure 1.4. This disc has permanent magnets (b) embedded in it.
When seen in cross section it is an inclined plane or wedge shape. This disc rotates freely around the central tube (e) impelled by changing polarities in the electromagnets (a) in the fixed disc (Figure 1.1) below. This rotation causes a bending towards the low side of the wedge and away from the high side as illustrated in the enlarged diagram of Figure 2. Figure 3.1 and 3.2 illustrate how this device is employed in a prosthetic finger joint. When the high sides of the wedge discs are alternated the appendage is straight but when the high sides are aligned, the joint forms a 90 degree bend. Since joints in a human hand rarely exceed a 90 degree bend, six wedge shaped discs with a 15 degree inclination would produce a 90 degree bend. Figure 3.3 is an enlarged cross section of a 15 degree wedge. In a prosthetic hand or limb, the discs would be concentrated only at the normal joint areas such as finger and thumb joints or ankle, knee, elbow and wrist. The embedding of pressure and temperature sensors at appropriate points in the appendage gives important feedback to the operator. This is particularly important in establishing and maintaining a grip on an object. If movement is to be limited to only one plane, such as in a finger joint, then programming pairs of discs to spin in opposite directions limits the movement to one plane. A
central tensioning cable (f) runs the entire length of the appendage. When a particular configuration needs to be temporarily "locked in", the cable, which is fixed at the far end of the manipulator, is tensioned at the base, either by a solenoid (i) or by a rotating screw mechanism, giving greater control.
When discs are placed along the length of the manipulator, the resulting configurations available mimic those of an octopus tentacle with its superior gripping power and directional versatility.
These abilities are particularly useful in everything from remotely operated vehicles (ROV's), both on land and in the marine environment, as well as in specialized types of medical probes. Figures 4.1 through to 4.4 show some of the possible configurations. Figure 4.1 shows the high sides of the rotating discs all lined up on one side of the appendage resulting in a circle. Figure 4.2 shows simultaneous bends to left or right while Figures 4.3 and 4.4 illustrate right angled bends to the left or right, or to front or back as movement is possible in all three planes of motion.
Spinning and non-spinning discs are protected by a tough synthetic "skin"
(Drawings page two, Figure 2, "h") in the case of a prosthetic limb, or by flexible metal or plastic sheathing in the case of assembly line work or heavy equipment activity. Suitable lubricants inside the "skin" facilitate the spinning discs and dissipate heat as well as making them unaffected by the extreme pressure found in deep water work.

While the drawings show only a simple orientation of four magnet and coil pairs, the number and placement of them in the discs will vary depending on both speed and torque requirements.
Likewise the angle of inclination of the circular wedges can be shallow, producing lower speed of movement but higher torque, or extreme, resulting in high speed of movement and much lower torque.
When used in Prosthetics, the electromagnets are activated in a pre-programmed manner by impulses picked up from nerve endings existing in the termination of an amputee's limb, or in the case of a quadriplegic, from any remaining muscle fibers that are still controllable. When materials are selected for light weight and strength, the power requirements necessary to operate an artificial limb incorporating this design should be minimal. The amperage and voltage requirements to activate or reverse the polarity of small electromagnets are very small.
However, the resulting torque produced is very powerful, which results in strong flexing, extending or gripping movements. Present day Lithium-Ion rechargeable batteries would be ideal and can be incorporated into the limb.
Remotely operated equipment can benefit from this design as movements can be controlled easily across severe pressure gradients such as those found in deep water or deep space vehicles. There is no need to have penetrating moving parts crossing the "inside-outside"
barrier. Only non moving electric wires are required and even this potential failure point can be avoided by using remote wireless activation.
Heavy equipment operation is moving in the direction of mechanisms which can be "worn" as opposed to operated. This manipulator design lends itself readily to this trend as operator movements can be picked up by "body glove" equipment or, more likely, by sensors similar to the "Kinect box" system in which hand or whole body movements are translated into equipment movements. Operator movements are then enhanced, strengthened, speeded up or slowed down, as required by this type of manipulator.

Claims (3)

1. A Multipurpose Manipulator activated and moved by means of rotating circular inclined planes. The movement is brought about by the interaction between permanent magnets in a circular inclined disc and the varying polarity of electromagnets located in a fixed disc.

2. The use of combinations of these disc pairs to produce movement in several possible planes, individually or simultaneously.

3. The use of a central tensioning cable to hold the manipulator in a temporarily rigid configuration giving enhanced strength and/or gripping capability.