C<v
244
OF THE PARTS OF
[sect. VII.
512. The teeth of wheels will be most conveniently given in a tabular form,
with a correction for curvature in determining their breadth, which is not in
cluded in the formula in my treatise on cast iron. The first column shows the
stress on the teeth in lbs.; the second, the horse power nearly equivalent,
when the velocity is three feet per second; the third column, the pitch ; the fourth,
the thickness; and the fifth, the breadth of the teeth : the sixth column shows the
greatest depth of the middle of the arm at the base in the direction of the wheels’
motion, when that part is one-third of the breadth of the teeth, and the radius is
one foot; hence, being multiplied by the square root of any other radius in feet,
it will be the depth for it; the seventh column shows the breadth of the rib which
strengthens the arm; and the eighth, the diameter of a cylinder, when the force
of the steam is thirty-five inches of mercury in the boiler, and the teeth move at
the same velocity as the piston. For any other velocity the stress will be founds/
by art. 500.
513. A Table of the Strength, &c. of Teeth and Arms
for Wheel Work.
I C I 7
Stress
in lbs.
Horse power
at 3 feet per
second.
Teeth of Wheels.
Wheel with 6 arms.
Diameter of
the cylinder for
low pressure
steam,—teeth
moving at the
same velocity
as the piston,—
in inches.
Pitch
in inches.
Thickness
in inches.
Breadth
in inches.
Depth of arm
for 1 foot ra
dius, in inches.
L
Breadth of rib
in inches.
C‘
22
0-25
0-25
0-119
0-75
0-87
0-25
2-0
85
0-5
0-50
0-238
1-25
1-24
0-42
3-7
191
1
0-75
0-357
1-75
1-67
0-60
5-5
337
2
1-00
0-475
2-50
1-76
0-80
7-4
520
3
1-25
0-590
3-00
2-00
1-00
9-2
800
4
1-50
0-730
4-00
2-20
1-30
11-3
1040
5
1-75
0-835
4-25
2-40 4
1-40
12-9
1370
7
2-00
0-955
5-00
2-50
1-70
14-8
1720
9
2-25
1-070
5-50
2-70
1-80
16-6
2100
10*5
2-50
1-190
6-00
2-85
2-00
18-4
2560
13
2-75
1-310
6-75
300
2-20
20-3
3000
15
3-00
1-430
7-25
3-20
2-40
22-2
3600
18
3-25
1-550
8-00
3-30
2-60
24-0
4150
21
3-50
1-670
8-50
3-40
2-80
26-0
4800
24'
3-75
1-790
9-25
3-50
2-90
28-0
5700
27-5
4-00
1-910
10-25
3-60
3-40
29-5
6300
31-5
4-25
2-025
10-50
3-70
3-50
31-5
6900
34-5
4-50
2-150
11-00
3-80
3-70
33-3
7700
38-5
4-75
2-270
11-75
3-90
3-90
35-0
8500
42-5
5-00
2-390
12-25
4-00
4-00
37-0