Automatic Devices Company

A Track & Machine
For Every Purpose
(including Hospital Facilities)

Mule Blocks


Mule Blocks are a means of allowing lines to pass over the edge of a sill without rubbing or binding. MB-1 is a single-wheeled ball-bearing pulley; MB-2 is a double-wheeled ball-bearing pulley and is used for muling double lines; MB-3 is used with Nos. 3503-A and 1403-A Center Take-Off Live End Pulleys while MB-4 is used with No. 5003-A Center Take-Off Live End Pulley. MB-5 is used with No.5003 live end pulley.


Adding turns of any degree to operating lines increases the overall load of the system. Allowance must be made for this additional loading when machines are used to operate the systems. The use of pulleys with wheels larger than those used in the MB series will lessen the effect of the added load.


 MB-1 Mule Block

General purpose

 MB-2 Mule Block 

Used with most track systems

also general purpose

MB-3 Mule Block 

Used with 3503-A & 1403-A

Center-take-off pulleys 

MB-4 Mule Block 

Used with 5003-Center-take-off


MB-5 Mule Block 

Used with 5003 Live end



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