TROLLEY ROCKER PRINCIPLE
For the satisfactory operation of a trolley on a monorail track it is necessary to provide for freedom of certain motions,
restrictions of other motions and elimination of still other move- ment tendencies. It is necessary for the trolley load bar
or attachment fitting to be free to swing or tilt at right angles to the rail to compensate for slightly out of balance loads, the
tendency to swing out on curves, off center lifting, etc. Most Spanmaster trolleys accomplish this by means of a
cylindrically shaped trolley rocker which rides in a mating trolley rocker seat as shown in sketch and permits a swing or tilt
up to 12 degrees each side of center.
Since the trolley rocker and the trolley rocker seat are
cylindrical in shape they permit the above mentioned
side to side swing and at the same time they eliminate
any tendency of the trolley to rock fore and aft in the
direction of the rail. This action would, of course, be
undesirable since it causes chatter of the trolley and is
detrimental to smooth, easy operation.
When negotiating curves it is necessary for the trolley
load bar to swivel laterally in relation to the trolley yoke.
If there is no provision for this swivel- ing the trolley will
bind on the rail and go around a curve with great
difficulty if at all. On the other hand if this swivel action
is too free the trolley will have a great tendency to
oscillate and chatter, especially on straight rail.
Spanmaster meets these requirements by permitting the
rocker seat to swivel in the yoke with just enough
resistance to prevent oscillation or chatter of the trolley.
DIMENSIONS ARE FOR ESTIMATING PURPOSES ONLY. REQUEST CERTIFICATION FOR CONSTRUCTION.
Copyright 1965
A DIVISION OF JERVIS B. WEBB COMPANY
Page 16.1
Jervis B. Webb co.
739 MOORE ROAD, AVON LAKE, OHIO 440121
0-1-80
