576 



Popular Science Monthly 



Grind Your Valves at Home. A 

 Machine Made for Car Owners 



GRINDSTONE. 



CENTERING HANDLE 



ADJUSTABLE 

 ARM 



MOVABLE SHAFT 



ROCKABLE BRACKET 



The valve head is held at an angle against 

 the rotating grinding wheel which drags it 

 around and bevels its edge into a perfect circle 



AN autbmobile cannot work efficiently 

 ±\. unless the engine-valves are in good 

 condition? The valves control the supply 

 and the exhaust of the vaporized gasoline 

 in the engine cylinders, and if they should 

 wear unevenly and begin to leak, the maxi- 

 mum amount of power cannot be obtained 

 from the fuel. Hence the valves should be 

 ground often, 



A machine for grinding the engine valves 

 accurately and rapidly has recently been 

 invented. The valve-heads, which must 

 be ground perfectly round so that they sit 

 tight against the circular ports or openings 

 in the cylinder, need only be adjusted in 

 this machine, and the grinding will proceed 

 automatically. Evidently such a machine 

 would enable an autoist with average 

 mechanical skill, to grind down the valves 

 of his own car. 



The illustration shows a 

 valve-head adjusted in position 

 in the machine. An emery 

 grinding-wheel is rotated at 

 the front end and the head 

 itself is held in place by a 

 holder at the other end. The 

 holder can be moved length- 

 wise in its bearings, while 

 the turn-table on which 

 it is mounted al'ows it 

 to be swung at an angle 

 to the plane of the 

 grinding wheel. The 

 valve-head is pivoted be- 

 tween two steel points on 

 the holder so that 

 it can freely rotate 

 on them. 



A small electric tu r * u , r u- , • 



^ 1 • I • The tront wheel of a bicycle is removed, 



motor, wnicn is placed in the rear, belted up with the other 



geared to the and an exerciser for leg muscles is made 



grinding-wheel, is then turned on. The 

 revolving wheel, with the edge of the valve- 

 head in contact with it, drags the head 

 continuously around. At the same time, 

 the wheel continuously "strikes off" side- 

 wise from the edge of the valve-head and 

 consequently bevels it down. The valve- 

 head rotates always a fixed distance from 

 the plane of the grinding-wheel, so that a 

 perfect circle will be obtained on the head. 



A person of only ordinary skill can grind 

 a valve with the machine described, on 

 account of the fact that the valve is always 

 in the proper position with relation to the 

 grinding wheel. Any standard valve can 

 be ground quickly and easily, as the only 

 change in the machine's adjustment is to 

 adapt it to a long stemmed valve or a short 

 stemmed valve. This is done by changing 

 the position of the arm on the shaft. 



When valves having stems of about the 

 same length are being ground it is not 

 necessary to change the position of the arm, 

 in view of the fact that the socket member 

 is adjustably mounted in the arm. 



The Bicycle to the Rescue 

 in Leg Treatments 



ONE of the simplest devices yet heard 

 of for restoring strength and agility to 

 soldiers' legs after they have recovered 

 somewhat from the effects of wounds, is 

 utilized at an electrical gymnasium which 

 has been started at Chateau D'Oek, in 

 Switzerland, by a French Adjutant and 

 C. S. M. McCarty _ (Leicester Regiment), 

 in the interest of British soldiers who have 

 been wounded and are convalescent. 

 The bicycle employed for the purpose 

 need not be of the latest model. Only 

 the frame and the two wheels 

 are necessary. Not even 

 tires are required. The 

 front wheel is taken 

 off and the frame 

 is fastened to a 

 stationary sup- 

 port. The wheels 

 are arranged at the 

 rear as shown in 

 the accompanying 

 illustration. 

 The tires are re- 

 moved and a belt 

 or rope support- 

 ing a weight is 

 carried over the 

 wheels. 



