Modified Stock Gearing - Boston Gear

Roller Chain Drive Tensioners
Type LG
Shaft Mounted
B
5/16"
G
E
MAX.
IDLER
SHAFT
J
This shaft-mounted tensioner is best suited for applications
where it is impractical to bolt the tensioner on a frame. This
tensioner can be mounted at any point on a shaft and is
adjustable to any location in a 360° arc on the shaft.
F
L
K
H
A
1/4"
GREASE
FITTING
D
GREASE
PORT
COLLAR
C
ORDER BY CATALOG NUMBER OR ITEM CODE
Suggested Catalog Item
Chain Number* Number Code
35, 40, 41 0-LG 48888
40, 50, 60 1-LG 48889
80, 100, 120 2-LG 48890
*Single-strand chain. For multiple strand chain, use larger tensioner.
ALL DIMENSIONS IN INCHES
Size A B C D E F G H J K L
0-LG 4 7/8 3/4 .500 1 2-1/2 1-9/16 7/8 1/16 1-5/8 .500
1-LG 6 1-1/4 1 .875 1-3/4 4 2-15/32 1-3/16 3/32 2-1/8 .875
2-LG 8 1-1/2 1-1/4 1.125 2-7/8 5-1/2 3-21/32 1-3/8 1/8 2-3/4 1.125
H
Type BG
Screw Adjustable
B
P
M
H
E
MAX.
J
L
These Boston Gear tensioners use a screw for precise, easily
adjustable tension, to provide maximum life for the sprocket
and chain. These tensioners are useful on vertical drives to
prevent lower sprocket disengagement and on heavy chains
where slack is normally taken up by hand, while making the
adjustment. With these tensioners chain take-up and tension
are both controlled with the screw.
Many drive systems are enclosed for safety reasons. With
conventional tensioners, the enclosure must be removed for
drive adjustment. With Boston tensioners adjustments can be
made to the head of the screw, substantially reducing cost
maintenance and drive down time. The screw is adjustable from
either end of the tensioner.
G
F
MAX.
G
K
2G
C A
5/16"
IDLER
SHAFT
1/4"
GREASE
FITTING D
GREASE
COLLAR PORT
ADJUSTING SCREW
ORDER BY CATALOG NUMBER OR ITEM CODE
Suggested Catalog Item
Chain Number* Number Code
35, 40, 41 0-BG 48878
40, 50, 60 1-BG 48879
80, 100, 120 2-BG 48880
*Single-strand chain. For multiple strand chain, use larger tensioner.
ALL DIMENSIONS IN INCHES
Size A B C D E F G 2G H J K L M P Wgt.
0-BG 5-7/8 1-1/2 5-1/4 .500 1 2-1/2 9/32 3/8 2-13/16 1-5/16 1-3/8 1-1/4 3/8 3/4 1 LB.
1-BG 9 2 8-1/8 .875 1-3/4 4-1/2 11/32 1/2 4 1-5/8 1-3/4 1-1/2 1/2 1 2-1/2 LB.
2-BG 13 3 11-7/8 1.125 2-7/8 6 9/16 3/4 5-11/16 2-5/32 2-7/8 2 5/8 1-1/2 6 LB.
294 Boston Gear 800-825-6544 P-1930-BG 04/10