CATALOG OF THE MECHANICAL COLLECTIONS 121 



GARVIN AND PETTIBONE TUBULAR GRATE, 1867 



U.S.N.M. no. 309216 ; original patent model ; transferred from the United States 

 Patent Office; not illustrated. 



This model was submitted with the application for the patent 

 issued to Benjamin Garvin and E. J. Pettibone, of Oslikosh, Wis., 

 February 12, 1867, no. 62022. 



The model represents a furnace grate formed of tubes designed 

 to be connected to the boiler so that water will be circulated through 

 the grates and be partially heated therein. The particular feature 

 of this invention is the manner of supporting and connecting the 

 tubes so that they might expand and contract freely. 



COLLINSON MANHOLE COVER FOR BOILERS. 1875 



U.S.N.M. no. 309219; original patent model; transferred from the United States 

 Patent Office ; not illustrated. 



This model was submitted with the application for the patent issued 

 to Henry Collinson, Boston, Mass., April 13, 1875, no. 161934. 



The invention consists of a lid or cover with a true flat face ar- 

 ranged in such a manner that while being forced home against a flat 

 seat it receives a sliding and rotating motion thereon. 



The model represents an opening in a plate around which is formed 

 a flat plane face, which forms a seat for the dish-shaped lid or cover. 

 A curved bar of metal spans the opening over the cover and supports 

 a threaded nut through which passes a T-handled screw by which the 

 cover is forced against the seat. At the inner end of the screw is an 

 eccentric head that fits m a recess in the center of the cover, so that 

 turning the screw forces the cover against the seat and moves the 

 center of the cover in a circle, while the friction causes the cover to 

 rotate somewhat about its own center. The result is a combined slid- 

 ing and rotating of the cover as it is forced against the seat. 



COCKRELL PULVERIZED-FUEL SYSTEM, 1876 



U.S.N.M. no. 308753; original patent model; transferred from the United States 

 Patent Office ; not illustrated. 



This is the model submitted with the application for the patent 

 issued to Allin Cockrell, of Lamar, Mo., August 1, 1876, no. 180550. 



The model represents a 2-door return-flue boiler equipped with a 

 pulverizing mill, a screw conveyor for supplying the fuel to feeding 

 spouts, and a paddle-bladed fan or blower. The fan, which has a 

 long, 4-bladed, paddle-wheel rotor, spans the front of the boiler. Its 

 cylindrical housing is extended as two ducts or spouts into the two 

 combustion chambers of the furnace under the boiler. The screw 

 conveyor from the pulverizing mill extends across the boiler over 



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