Abstract This invention describes an improved type of magnetic tape drive for computers in which a vacuum column is provided. A vacuum pulls the tape into the column, and the tape is pulled out by the capstan to the heads or, by the reel drive system. The system of this invention utilizes a plurality of small holes drilled through the back wall of the column down the length of the column, and a very narrow slot colinear with the drilled holes is provided in the front surface of the back wall. This narrow slot provides a certain amount of leakage of air from the high pressure above the tape into the vacuum below the tape. Thus as the tape moves downward, the small holes can sense the approach of the tape because of the leakage of air through the slit in advance of the tape loop. Thus by measuring air pressure in a chamber behind this set of holes, the position of the tape loop can be sensed on an almost linear basis, from one end to the other of the column. Servo means are provided to use this sensed position to continuously drive the reel motor.
Inventors
👤 J Henderson
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-27 13:50
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/56; G11B15/58
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
139 words
In a tape handling system including at least one vacuum tape column for controlling a loop of tape, in which a plurality of small diameter holes are provided along the centerline of and through the back plate of the column, with a plenum chamber at the back of said plate, pressure sensor means to measure the pressure in said plenum, and servo means responsive to said sensor means to control the reel drive system, the improvement comprising: a narrow longitudinal channel of uniform cross section cut into the front face of said back plate colinear with the line of said plurality of holes, whereby air will leak through said channel from the high pressure above the loop into the low pressure below the loop and said sensor will have a more linear indication of the position of said loop.
Claim 2
Dependent Claim
139 words
In a tape handling system including at least one vacuum tape column for controlling a loop of tape, in which a plurality of small diameter holes are provided along the centerline of and through the back plate of the column, with a plenum chamber at the back of said plate, pressure sensor means to measure the pressure in said plenum, and servo means responsive to said sensor means to control the reel drive system, the improvement comprising: a narrow longitudinal channel of uniform cross section cut into the front face of said back plate colinear with the line of said plurality of holes, whereby air will leak through said channel from the high pressure above the loop into the low pressure below the loop and said sensor will have a more linear indication of the position of said loop.
Claim 3
Dependent Claim
23 words
The tape handling system as in claim 1 in which said channel is at least five times as deep as it is wide.
Claim 4
Dependent Claim
24 words
The tape handling system as in claim 1 in which said channel is less than 0.020 inch wide and more than 0.100 inch deep.
Claim 5
Dependent Claim
30 words
The tape handling system as in claim 1 in which said channel is in the range of 0.010 inch to 0.025 inch wide and 0.075 inch to 0.200 inch deep.