Linear digital readout assembly for milling machines and the like and means for mounting same

A digital readout assembly for milling machines and the like to provide a digital display indicating relative movement between relatively movable parts of the machine, comprising:

• a housing means, an elongate scale means fixedly carried by the housing means;
• adjustable mounting means connected with said housing means and secured to one of said machine parts rigidly securing the housing means and scale means to said one machine part in predetermined, adjusted, aligned relationship relative thereto;
• reading head means disposed in preassembled, prealigned, operative relationship to said housing means and scale means and free of engagement with said scale means;
• adjustable reading head mounting means secured to the reading head means and to another of said machine parts rigidly securing said reading head means to the other of said machine parts in predetermined, adjusted, aligned relationship relative thereto;
• removable pre-alignment spacer means on the housing means engageable by said reading head means to prealign the reading head means relative to the housing means and scale means;
• and digital display means connected to the reading head means to give a visual indication of relative movements between the scale means and reading head means and thus between the relatively movable machine parts, whereby during installation of the assembly on a machine, the reading head means can be accurately aligned relative to said scale means while being maintained in spaced relation thereto, and after alignment of said reading head means relative to said scale means, said removable spacer means is removed so that said reading head means is free of engagement with the housing means and scale means during use of the assembly, and relative movement between the reading head means and scale means is guided solely by the machine ways and is thus dependent only upon the relative movement between said relatively movable machine parts and relative movement between the machine parts is thus accurately measured and indicated.