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Title: |
1911 Articles-Alfred Herbert Ltd., #6 Sensitive Vertical Drill Press & Multiple Spindle Vertical Drill |
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Source: |
Machine Tools Commonly Employed In Modern Engineering Workshop, V2, 1911, pg. 3 |
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Insert Date: |
4/6/2020 9:30:15 PM |
A larger sensitive drilling machine, built by the same makers, Alfred Herbert, Ltd., of Coventry, is illustrated in fig. 223. This machine drills holes up to 1 in. diameter, and the stroke of the spindle is 6 in., an adjustable stop being provided, as in the previous example, to limit the travel of the drill to suit the depth of hole required. It will be seen that the frame of the machine is of a stronger and more rigid construction, and that the table and spindle are adjustably mounted upon a broad machined facing on the front of the column. When the table is lowered the spindle head can also be lowered, to reduce to the minimum the projection of the drill beyond the head. The spindle and the spindle head are independently balanced by counterweights, which facilitate the working of the machine. There are six spindle speeds available, and means are provided for tightening the belt. If the machine is required for tapping purposes, pulleys for reversing the motion can also be provided. The belt shipper is operated by means of the treadle, shown in the illustration.
For gang work of a light description multiple drills are commonly employed. In the case of a four-spindle machine, such as is illustrated in fig. 224, each spindle may be equipped for a different operation, or for drilling a hole of different diameter, and thus the frequent changing of the drills or other tools is avoided. The piece is moved about on the table from one spindle to the other, and it can generally be f1nished at one handling and without stopping the machine. Multiple-spindle machines of the type illustrated are therefore very serviceable when quantities of a particular piece have to be dealt with. With the exception of the design of the multiple-head frame, the machine illustrated does not differ greatly from the sensitive drills already described. Owing to the high speed at which it is desirable to run the drills, ball bearings can be applied to drilling machines with advantage, and where such bearings are used the output is considerably increased. |
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1911 Alfred Herbert Ltd., #6 Sensitive Vertical Drill Press
1911 Alfred Herbert Ltd., Multiple Spindle Vertical Drill
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