Posts Tagged ‘Meredith Thring’

1962 – Table-Clearing Robot – Meredith Thring (Australian/British)

"Working model of a table-clearing robot [Mk 2] designed to test the present-day feasibility of principles required for the house-working robot and other machines. The model has one 'sight' and two 'touch' sensors which enable the mechanical arm to pick up objects and place them on the rotating, clearing tray on top of the machine."

INVENTORS' EXHIBITION

2065.27 | INVENTORS' EXHIBITION. London 13/01/1969

M/S table clearing robot. M/S as it lifts cup up from table. C/U cup being lifted from table and placed to one side. M/S as cup swings round to make room for another.


THE HOUSE-PROUD ROBOT
Clearing the table after a meal is a task which can be given to a robot. This one, like many other robots, does not have a human form like its counterparts in fiction. But it does its job well.


1. The mug is seen by a photoelectric "eye" and the "hand" is directed towards it.
2. Controlled by pressure sensors, the hand grips the mug firmly.
3. As the hand retracts, it puts the mug on a rotating turntable.


4. By its rotation, the turntable clears the mug out of the way. Far right: a close-up of the robot housemaid in action.


This table-clearing machine has a photoelectric eye which detects objects. This directs linkage; closes on them
lifts them back to the turntable.




Earlier Mk 1 version of Table-clearing Robot


Meredith Thring with his models of Domestic Robot

Cartoon from New Scientist, March 1963.


See other early Domestic Service Robots here.


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1964c – Walking Wheel Stair Climbers – Meredith Thring (British)

Stair-climbing wheels

Wheels that shoot out spring-loaded "legs" enable an experimental British vehicle to climb stairs and other obstacles. The vehicle, powered by batteries, is the "miniclimber," developed by Prof. Meredith Thring and Brian Shayer at Queen Mary College, London University. The small machine travels at about three mph. On level ground, the weight of the miniclimber pushes the climbing legs back into a hub that's located alongside each conventional wheel. The developers foresee the climber's use by handicapped persons.

Source: Popular Mechanics, June 1967.

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Click on above image to see Video clip of the Step-climbing carriage.

Towards the end of the Newsreel,  Bernard (Bob) Morris sits in a step-climbing carriage; hooks come out of the wheels to pull the carriage up a small stairway; this was designed for the use of Thalidomide victims. [The British Pathe blurb on this newsreel incorrectly says the driver is Charles Ford when in fact it is Bernard (Bob) Morris. Thanks Andree McDade for this correction – see Comments below].


Prof. Meredith Thring with his Stair-climbing Chair.


Fig. 6-11.

Source: Robots and Telechirs, M. W. Thring, 1983.

Thring has worked on an electrically powered carriage with three or four rimless wheels to enable handicapped people to climb stairs freely, which essentially places its spokes (rubber-tipped) on the step in front of it so that like a human foot it has no tendency to roll down the inclined plane formed by the corners of the step, because the weight is always carried on a horizontal surface.

The motion on the staircase is not perfectly steady because the point of contact of the spokes may be very close to, or even right on, the edge of the step, or it may be up to the distance between the spokes from the edge. However, it is considerably smoother than any system which rolls along the step and then climbs up to the next one, and there is a certain smoothing effect between the front and rear wheels.

Figure 6.11 shows an early working model of this kind of machine with four driven wheels having twelve rubber tipped spokes on each. By having driven front and rear wheels it gradually changes angle as it comes to the beginning and end of the stairs. If the spokes are too sharp they wear the rubber tips very fast, but if they are too thick they tend to come on the rounded corner of the step more often and can roll (on the downward movement) or slip (on the upward movement) on to the next step. The optimum number of spokes is also a very important consideration. The wheel should have a radius (when the spoke is loaded) slightly greater than the height of the highest step to be climbed, so that as it rolls forward on the step below the spoke comes forward on to the next step. If there are too many spokes the spoke always begins to lift from a point very close to the edge of the step-tread, and the smoothing effect of the edge going deep between the treads is lost. If there are too few, the reciprocating motion when going on the level ground at higher speed becomes excessive. Twelve spokes give noticeable oscillation at 3 m.p.h. on the level. The amplitude of the oscillation is inversely proportional to the square of the number of spokes, so 16 or 20 would be better from this point of view though more expensive.

There are two problems which must be overcome in a final design.

(i) Stability. It is desirable that the seat carrying the person shall tilt so that this seat remains approximately horizontal when the chair ascends or descends stairs. If the chair is pivoted about a point above the centre of gravity of the person so that this levelling is automatic on the pendulum principle, then his weight will be thrown in the downstairs direction on the tilting of the chair, making the system fundamentally unstable. It is, therefore, necessary to tilt the seat about a pivot close to the ground or to slide the seat upstairs as the carriage tilts. In either case the weight has to be lifted and thus the levelling mechanism must be powered, unless the movement is carried out by the driver before reaching the stairs at the same time as he changes to low gear for stair-climbing. It is also possible to have front- and rear-wheel drive only when in the climbing mode.

Steering. 

Steering a system of this type requires front- and rear-wheel drive when it is climbing stairs. Moreover, it should have very good mobility corresponding, if possible, to complete rotation about an axis within the framework. This rules out conventional steering methods unless the driven front wheel can be rotated up to 90° in each direction, a proposal which is being explored at UNAM in Mexico.

My own solution is shown in Fig. 6.12. It is preferable to have only three wheels because, when climbing a spiral staircase, which is not a plane surface, a four-wheeled system would require very soft springing to adapt to the surface. By making the front wheel with rollers at the end of all the separate spokes (Fig. 6.13) this wheel will give positive drive for moving forward, but can roll freely sideways. Thus, if the two rear wheels are driven by separate motors, which can be reversed, and the front wheel is driven by a differential gear so that it runs at the arithmetic mean of the speeds of the two rear wheels, it is then possible to rotate about the mid-point of the back axle. The front wheel need not be driven except in the climbing mode and the drives to the rear wheels have to be reduced by a 6:1 ratio mechanical gear in order to give the necessary increased torque.


See Thring's other things here.

See other Walking Wheels and Walking Machines listed here.


1963c – Two-Legged Walker – Meredith Thring (Australian/British)

Source: How to Invent: M.W. Thring and E.R. Laithwaite, 1977.

In the first stage of an attempt to make a powered artificial leg I analysed the essential mechanism of human walking and produced the device shown above which walks on two legs by bending the knee as the thigh begins to swing forward and straightening it as it begins to swing backward.

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Thring with 2-legged walker.


Prior to the above electric-powered walker, Thring built a compressed-air powered mode. 

Source: Robots and Telechirs, M.W. Thring, 1983.

Figure 6.26 shows the linkage mechanism used by Thring in some early studies for a powered orthotic or prosthetic leg. This consists of two parallelograms so that two pneumatic cylinders can provide the whole walking movement and the foot is maintained parallel to the ground. The upper cylinder swings the leg by changing the diagonal of the upper parallelogram, while the lower one lifts the foot by bending the knee.

Fig. 6.26 — Pantograph leg mechanism.


Source: New Scientist, 7 Mar 1963.

… when a domestic robot will take over the routine of running a house ….. the fortunate house-holder ought to be able to turn a switch and give the robot instructions to do  everything. It will make the beds. change the sheets, dust the whole place. vacuum, clean the carpets, lay the table and clear it and look after other machines as well —it could be instructed, for instance, to feed the washing machine.
The machine would have to walk, not run on wheels, so that it could negotiate the edges of carpets and go up and down stairs. A mechanism for doing this has been developed at Sheffield. It works by a system of telescopic legs and feet and an extendable cantilever arm. Professor Thring showed a film of the machine, powered from a compressed air line,
coming down a flight of steps and then propelling itself along the flat, rather like a monkey taking the weight on its knuckles and swinging its back legs forward.


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1967 – Centipede Walking Machine – Meredith Thring (Australian-English)

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US Patent number: 3522859 – see here for full patent details.
Filing date: Jan 22, 1968
Issue date: Aug 4, 1970
First filed in Great Britain 26 Jan 1967

Model of Centipede.

The 'centipede'
In the first model (Fig. 6.15(a) above) of the centipede the sprung legs were operated with two chains, one arranged half-way up the legs and one attached to the top of the legs, so arranged that the legs were always held vertically. Each leg is separately sprung and can have various types of feet on it (Fig. 6.16-not shown). However, a fundamental advantage of separate legs is that if one has a solid rubber pad for each foot, with no track on it at all, it still gives a good grip on soft ground because the front and rear edges of the foot act as the track. The actual weight is taken on a rail with a roller feed to the leg running on it. 


Mechanical Elephant

Above: Small-scale working model of mechanical elephant designed for rough- country load-carrying and a wide range of jobs required in developing virgin land for agricultural purposes. The legs of the 'centipede' track are individually sprung, giving the machine a capability of climbing vertical objects up to one-and-a-half metres high in the proposed full-sized version. The machine could also cross rivers and lakes.

A study of this machine showed that it is not essential to have the legs moving vertically when they come down to the ground and they can come round a circle at the front and still give the same ability to climb stairs. The next version shown in Fig. 6.17 above can be described as a caterpillar track with legs. Each element of the caterpillar chain consists of T-shaped piece, joined to the next element by rollers at the corners of the crossbar of the T with the stem of the T forming the sprung leg. The two rollers run on rails which are concave upwards so that slightly more weight is taken on the middle feet than on the end ones, to make turning easier. The chains are driven by a hexagonal wheel at each end, with grooves in them that mesh with the rollers. If one has too few corners on these wheels there is too much variation in the speed of the track as the wheel rotates because of the difference in the radii of the circumscribing and inscribing circles of the polygons hence the wheels should be at least hexagons. The rail has to be located with its end at the radius of the circle traversed by the insides of the rollers.
The other proposal (Fig. 6.18 below) has been specifically put forward for the problems of carrying tree trunks over areas where tree stumps are frequent, and for operating sugar beet or potato-extracting machines in a very wet season.
This has a single rubber track supporting low-pressure pneumatic rubber legs, which are preferably elliptical in cross-section, with the long axis in the forward direction, so that they can bend more easily sideways than backwards under load. The belt is driven by a toothed drum on each end, with the teeth meshing with grooves on the inside of the belt. The flat raised part of the teeth on the belt is coated with a low friction plastic and runs between the two drums on a convex-downward smooth steel rail, in the form of a wide plate, which takes the load.

 Source: Robots and Telechirs, M. W. Thring, 1983.


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1962 – Robot Fire Cart – Meredith Thring (British)

Thring, at Queen Mary College built a fire-fighting robot in 1962. This robot navigated its way round a "track" using signals from a gyro compass and measuring distance by wheel-rotation. It left the track when it "saw" a fire and extinguished the fire when its "finger" sensed the flame. The idea was to develop a fully automatic night watchman that could travel around a warehouse and look out for a fire. [Source: New Scientist 19 Nov 1981]

A demonstration robot firefighter built in 1962. It followed a track plotted on the table, detecting the track by photocells, and determining its direction by the gyro compass at the back. The distance travelled was determined by counting the revolutions of the back wheels and the drive and steering were by the front wheel which could be rotated by ± 90° from straight. An arm sticking out in front carried a bimetallic switch and there was a photocell detector on a headlight fixed to the front wheel carriage. This carriage oscillated during the steering process and if the photocell caught sight of a flame the robot left its track, homed on the flame, and when the bimetallic switch detected the heat of the flame the robot stopped and brought the fire extinguisher nozzles onto the flame. This first prototype was liable to chase the sun! [Source: Thring – Robots and Telechirs]

In the above image, you can see a drawing of a closed-loop. This represented the route the cart was to follow. It is essentially a line-following robot. The route was ignored once a fire was detected.


VIDEO CLIP

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Enter 83414 in Search Story – press Search, then play clip.

Most references date this robot at 1962, but the film clip is dated December 1961.


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