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Title: |
1931 Article-Grob Brothers, Grob Model B-1 Bench Filing Machine |
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Source: |
American Machinist, V74, 26 Mar., 1931, pg. 523 |
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Insert Date: |
3/26/2025 10:44:05 PM |
Grob Model B-1 Continuous Filing Machine
A bench-type, continuous-band filing machine has been added to the line manufactured by Grob Brothers, 90th & National Avenues, West Allis, Wis. This type is designated as the Model B-1 and is designed for either external or internal filing of small and medium-sized work that requires fitting or forming. It is suited to tool and die making, in that deep, flat surfaces up to 4 in. in height can be finished within close tolerances. The features include: automatic tension to the main driving belt; a positive drive to the file chain; a full-support back rest; a positive adjustment to the work table; three filing speeds; and employment of a band of files to give continuous cutting action.
The continuous chain is made up of a series of files that are joined together by links so that they operate on two sheaves. The motor is mounted at the rear and drives the main drive pulley by a V-belt. Drive from the main pulley to the lower sheave is also by V-belt. Automatic tension on the main drive belt is accomplished by mounting the main drive pulley on a hinged bracket. As the filing pressure is increased, the tension on the belt likewise increases and thus aids in obtaining a constant, smooth drive.
In addition to the V-belt drive, a series of driving pins, located within the groove of the lower sheave, offer a positive drive to the chain and prevent slippage in the event excessive pressure is applied. The drive pins are provided with a floating action, so that they can seat and adjust themselves properly against the back edges of the links and yet offer a positive drive.
A channeled link is securely welded to the back of each file, which not he files together, but also offers a positive alignment with the back rest. The back rest is grooved to receive
Grob Model B-1 Bench-Type Continuous Filing Machine for work up to 4 in. high
this link and is so made that it offers adequate support directly against the back faces of the files. The channeled links are connected with a series of straight links by pins and flat springs, so that they form an endless chain. This chain is of the self-locking type, but can be disengaged easily when it is to be used for internal filing. Filing chains can be furnished either flat, half round, or diamond shape.
Tension on the filing chain is adjusted by a handwheel at the right side of the machine. It connects with a bracket that moves the upper sheave up or down as desired. An adjustable rubber-covered roller keeps the chain of files firmly against the back rest. The work-table can be adjusted 25 deg. either forward or backward. A graduated plate and pointer are used for the purpose of setting the table to the desired angle, whereas positive adjustment is made by a small handwheel located at the underside of the table.
The filing machine is 29 in. high and occupies a space of 15x15 in. The table is 13 in. above the bench and has a working surface of 12x14 in. The machine weighs 150 lb. |
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1931 Grob Brothers, Grob Model B-1 Bench Filing Machine
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