Popular Science Monthly 



657 



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 



