Bucyrus 3

BUCYRUS ERIE 50-B

STEAM SHOVEL

Part three by Alberto Celot

The work continues with the design of the Truck Frame, that is, of the lower part which comprises the tracks for moving along the ground. The movement transmission is effected through an axis coaxial to the pivot pin and two back gears fitted with bevel gears that also serve to reduce the speed of rotation. The motion is then applied to the two tracks by means of two joints with manual insertion jaw clutches.
The axis at the opposite end is provided with two devices for adjusting the tension of the tracks.
And here is an image (the bevel in the centre is drawn in simplified form).
The next pair of images are of the joints with jaw clutch and they are, first, in the disengaged position and the second engaged position.
The work continued with the design of the main boom (‘Boom’), the sliding arm (‘Dipper Handle’) and bucket (‘Dipper’). It was not easy, because I had to rely almost exclusively on photos and measurements taken with some difficulty, with all the problems that this entails. In the end, though, I was pleased with the result. Let's start with two images of the Dipper. The bottom hatch is opened by pulling the lever of the latch and closes simply by gravity when the Dipper is lowered so that the hatch is going to close the bottom. The lever is pulled by a chain connected to a drive which we will see later. Here are two images of the Dipper: The Dipper is constrained to the sliding arm Dipper Handle, which in turn is connected to the boom by means of two racks placed on the lower side. The upper side is harnessed to Boom by two guides (‘Saddle Block’) that allow it to slide. Two images of the Dipper Handle act to clarify the operation:
On the right side near the Dipper you may notice pulleys and a vertical cylinder: this is an assembly that allows keeping he steel rope that releases the door of the dipper in traction, by means of a spring placed in the vertical cylinder.
The main arm ‘Boom’ is hinged to the base of the revolving frame and can be raised and lowered by the winch. Two anchoring devices mounted on each of the two sides allow the structure to be strengthened by bolts (not shown). The Thrusting engine is mounted on the boom which provides the movement of the Dipper Handle. On the right ‘Saddle Block’ is mounted a steam operated cylinder which provides, through a system of pulleys, the pulling of the rope to release the Dipper door. The third of the images below glimpse pulleys release system of the rope.
Finally this week, the stage that the design has now reached.
ED: Next time Alberto starts making complex parts for the model, including the introduction of one technique that we believe is new to model engineering.

Part one part two part three part four part five part six part seven Part eight
part nine part ten part eleven part twelve Conclusion

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