Page:Popular Science Monthly Volume 88.djvu/685

 Popular Science Monthly

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��The Electromagnetic Hand for Armless Veterans AT a meeting of the Verband Deiitscher xV Elektrotechniker (Association of Ger- man Electrotechnicians) the suggestion was made that the Verband consider the design and development of artificial arms, equipped with electro- magnetic seizing and holding mechanism. The underlying idea is simply this:

���Construction of the electromagnetic hand. To the left, how the hand is used in sawing

The sleeve enclosing the stump of the arm is provided at its outer end with a pot-shaped or bell-shaped magnet, which can be ad- justed or held in a ball- end socket, so as to bring the retaining face of the magnet to any position de- sired. The magnet may then be either clamped tight or else left movable against slight resistance. The pot- magnet is connected with a current supply by means of a screw-plug. Connection is made by moving some other part of the body, for exam- ple the foot, the chin, the re- maining arm, the dam- aged arm itself, or even the whole body.

The pot-magnet makes it possible not only to grasp all iron objects, but also to

��hold them tight or to lift them and move them for any length of time. During these manipulations the connection be- tween the stump and the object (tool) is not a rigid, but a movable one. For this reason the magnetic hand may be used by all workmen who work with iron tools

or iron articles. As a

rule, the tool need not be specially altered or given a special shape for the mutilated man, since the magnetic hand is capable of grasping the tool at any place, provided it is made of iron.

In filing, for in- stance, the magnet is placed on the outer end of the file. The file is moved exactly as if it were guided by a healthy arm; for the magnet can move relatively to the sleeve. A car- penter's plane is provided at its extrem- ity with a small iron disk and is manipu- lated in exactly the same manner as any other plane. Stampings cut out by ma- chine dies can be removed perhaps with greater ease than with a normal hand. Still other grasping movements, for instance a pinching movement, may be carried out without dif^culty. Even the delicate closing movement of a pair of pliers may be efTected.

��'Ball and socket joint 'Elecfromaqnef

���The plane must have a piece of steel on its upper face so that the electromagnetic hand may have a hold

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