Photo Index - Hoggson & Pettis Manufacturing Co. - 3 Jaw Chuck N50

Machinery Photo Index

Manufactured/Badged by:
Hoggson & Pettis Manufacturing Co.
New Haven, CT

Machine Specifications
Machine Class:	Metal Working Machinery
Machine Type:	Lathe, Metal
Machine Size:	10.5 inches
Submitted By:	Mike Fendley

Machine Specifications
Description/Model:	3 Jaw Chuck N50
Date of Manufacturer:	1849-1879
Serial Number:	NA
Last Updated	12/4/2018 11:15:13 AM

Comments:

The Sweetland Chuck
Hoggson and Pettis MFG. Co.
New Haven, Connecticut

10.5” Three Jaw Universal/Independent Chuck

I acquired this chuck off a 1902 Barnes #13” x 33” lathe. (I also have the Barnes #13” x 96” lathe, the longest bed Barnes made.) After clean up I discovered the Hoggson and Pettis stamp on the face of the chuck with the model number N50 stamped above and below the #1 jaw screw (on each case half of the chuck.) The H&P Company started making chucks in 1849. However, the unique universal / independent ability of the 3 jaws, plus the recessed male square drive for each jaw were both patented by the Skinner Chuck Company in 1879. Subsequent pictures of H&P chucks from a 1913 catalog showed a recessed female square drive for tightening chuck jaws plus 2 piece jaws for their 3 jaw chucks. The chuck I have has solid jaws. Therefore the age range of this chuck could probably be from 1849 to 1879 assuming they did not infringe on the Skinner patents. The chuck, though covered in rust, had very few dings or abuse. The jaws were in excellent shape but had some wear on the “points.” What is unique about this chuck is that each jaw can be adjusted while on the lathe independently. This helps in timing the jaws to come together concentrically and can be used to adjust for wear. When I had the chuck apart I noticed the odd screw thread for each jaw, 7 tpi, LH. However, that was coupled with a 14 tooth bevel gear. When you do the math, 1/7 gives .143 thousandths. Divide .143 by 14 and you get .010. Essentially by moving the circular bevel (almost like a rack) gear away from each bevel gear screw and advancing or retarding the screw by one tooth, you can move the jaw in or out .010 to make it come closer to concentricity for all three jaws. A small internal “ramp” has a 1/4" x 24 tpi threaded shank on its back that sticks through a slot on the back of the chuck. Loosen the round nut, and you can slide the ramp away from (toward the spindle) the circular bevel gear disengaging the bevel gear screw from the circular bevel gear, so that each screw can be turned independently and time the jaws. Slide the ramp to the outer edge of the chuck raises the circular bevel gear and engages the bevel gear of the screw. When all three screws are engaged in this manner by the circular bevel gear, you have a true universal chuck with all jaws moving simultaneously. Each “round nut” had a one way cover over it similar to the type of retainer you used to see on the axles of “little red wagons.” Taking them off destroyed them so I used a pair of fender washers to cover each slot and give the round nut a surface to press against. The bore on the chuck is 1.75. However, the spindle on a Barnes #13 is 1.25 x 7 tpi with an MT2 taper not allowing the chuck to make use of the generous 1.75 bore. The flange nuts holding the chuck mount to the chuck are modern as the original nuts were stripped and of the wrong thread. The chuck weighs in at 33.5 lbs.

[ADMIN NOTE: Original date of this entry was 1/6/2014. Updated to fill in manufacturer fields.]

Photo 1:

Comments: Jaws closed
Source: Mike Fendley

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Photo 2:

Comments: Jaws open
Source: Mike Fendley

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Photo 3:

Comments: Back
Source: Mike Fendley

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Photo 4:

Comments: Before - Front
Source: Mike Fendley

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Photo 5:

Comments: Internal ring gear ramp
Source: Mike Fendley

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Photo 6:

Comments: Label and model #
Source: Mike Fendley

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