History of the Starter Motor, Bendix starter drive, and Agricultural Engineering

Starter motors have been fitted to internal combustion engines (ICE) for many years. British agricultural engineering company William Arnold and Sons, East Peckham, Kent, trading as the Arnold Motor Carriage Company, is credited with fitting a first electric starter by electrical engineer H.J. Dowsing to a Benz with Arnold's engine in 1896. The Arnold Benz is also the first car to have exceeded the speed limit (source: Motoringnews.org) Records of starter motor patent attempts go back to 1899. The Bendix starter motor drive mechanism used on classic and vintage vehicles up until around the 1970's era, was invented in 1910 by Vincent Bendix. A Dayton Engineering Laboratories Company (Delco) starter motor was fitted to a General Motors (GM) Cadillac vehicle in 1912. Due to gear meshing problems liable to cause damage to starter pinion gear and flywheel teeth, bendix type starter motors for ICE's were largely superceded by pre-engaged starter motors which operate the motor pinion gear to flywheel teeth by a lever moved by the electromagnetic action of a solenoid, which again is a development of the agricultural tractor starter motors of the 1940's 1950's and 1960's where the starter gear was manually engaged with the flywheel teeth by pushing down on a lever which also pushed on a contact switch wired back to the coil circuit of a seperate electromagnetic solenoid causing the solenoid plunger to move a set of contacts.
The closing of remote solenoid contacts operated a relay effect supplying heavy current power feed to the starter motor B+ terminal. The Starter motor B+ terminal is connected internally to the starter motor brushes, or brushes and field coils depending on starter motor design. Brushes contact the copper bars of the commutator which is shaft mounted adjacent and connected to armature windings. Electrical current returns via the earth brush and wiring to the vehicle battery. Earth return circuit may be via chassis rails or insulated return depending on application and design.
In the United Kingdom, the Joseph Lucas company of Birmingham was heavily involved in Starter motor manufacture and used much publicity directed towards the agricultural industry with a range of factory remanufactured starter motors under the B90 'immediate exchange' program designed to hold stock at local motor factors, garages, and agricultural engineers to cut downtime associated with electrical breakdowns on tractors during peak crop sowing and harvesting periods.

Reference sources and learning resources:

Laukkonen,J (2013) 'History of the starter motor' www.crankshift.com
Wikipedia, https://en.wikipedia.org/wiki/Vincent_Hugo_Bendix
Wikipedia, https://en.wikipedia.org/wiki/Bendix_drive
GM, Wired).
Youtube video (no affiliation) Starter Motor Explained - How a car's electric starter motor works

Motor Engineer Henry Ford also originated from an agricultural background. Unfortunately, our parts stock does not go back quite this far although we are able to source starter motors for modern vehicles.