US2510552A - Pneumatic record sensing device - Google Patents

Description

June 6, 1950 Filed Jan. 29, 1948 FIG. I Y

U I \x ,Y 39/ 369 .945 387 f 353 x L ,,393 y \377/ x 384 37; g FIG. 2

E /4/ I FHLVEgTORS arr 11 35/) 359 0. L Hibbfzrd i I BY L. 1 W F LMW F. M. CARROLL ET AL 4 Shets-Sheet 1 AT TOR N EY June 6, 1950 F. M. CARROLL ETAL PNEUMATIC RECORD SENSING DEVICE 4 Sheets-Sheet 2 Filed Jan. 29, 1948 INVENTORS F. M. Carroll 0. L .Hibbard )W ATTORNEY Nmm mmm

June 6, 1950 5 F. M. CARROLL ETAL 2,510,552

PNEUMATIC RECORD SENSING DEVICE Filed Jan. 29, 1948 4 Sheets$heet s INVENTORS F. M. Carroll 299 8 BY 0 L .H/bbard June 6, 1950 F. M. CARROLL EIAL 2,510,552

PNEUMATIC RECORD SENSING DEVICE Filed Jan. 29, 1948 4 Sheets-Sheet 4 FIG. IO

INVENTORS f. M. Carroll BY 0 L Hibbard ATTORNEY Patented June 6, 1950 PNEUMATIC RECORD SENSING DEVICE Fred M. Carroll, Binghamton, and Oscar L. Hibbard, Johnson City, N. Y., assignors to Enternational Business Machines Corporation, New York, N. Y., a corporation of New Yo Application January 29, 1948, Serial No. 5,134

16 Claims. 1

This application is a continuation in part of our copending case Serial No. 686,636, filed July 27, 1946.

This invention relates to record feeding and analyzing devices and more particularly to an advanced form of pneumatic sensing device for cooperation with perforated tabulating cards to repeatedly sense same or different fields of perforated data in one of such cards.

An object of the invention is to provide im proved pneumatic sensing devices for cooperation with perforated records, thereby making it possible to sense such records without the usualcontact therewith incidental to the use of ieeler pins or electrical sensing brushes. The object is to construct the pneumatic controls with pressure and a forwardly directed vacuum action rather than a suction action, and thereby cause the lint, dirt, and other loose matter to be blown away from the sensing unit and card and directed into an exhaust opening away from all the sensing mechanism. Thus, the action produced is dual in a combined cleaning and reading operation.

The pneumatic action of the disclosed devices with air pressure in a direction toward an exhaust portv and away from the pneumatic unit exercises a useful scavanging action to clean the card at the same time that it is sensed.

Another object of the invention is to provide a compact pneumatic sensing device for cooperation with perforated record material. The sensing unit is designed to be fitted in 2. lim-- ited space by having a double tiered arrangement of pressure chambers with a staggered array of cylinders and pistons. This design makes it possible to have a large number of closely spaced air ports arranged side by side in a single line, and yet extending from such ports are a series of cylinder openings and pistons of substantial size leading to the air chambers and tubes for supplying the pistons with the activating air pressure and enabling a substantial electrical reading device to make contact under control of the pistons. The piston or plunger is arranged to have comparatively large clearance in the surrounding cylinder walls leading to the port opening directly above the perforated record terial. The air pressure behind and in front of the piston is equalized as long as the advancing record material. appears imperiorate under the air opening. However, as soon as a data representing perforation appears under the opening, the air on the record side of the piston escapes, creating; a low pressure area or vacuum under the piston head, thus causing the air on the intake side r of the piston head to exert enough pressure to cause it to move toward the sensing port. This motion is communicated to a flexed contact wire or blade which is then brought into electrical contact with a common conducting bar.

Another object of the invention is to. provide pneumatic sensing devices wherein the moving parts for establishing electrical contact are so small and light that they have a rapid operating cycle and fast restoration movement in order that they will sense code perforations in adjacent index positions appearin in rapid succession under the air ports.

Another object of the invention is the provision of a hollow record holder to carry the record under analyzing devices, as shown, the holder is a hollow drum wherein the lint, dirt, paper threads, etc. from the record may be blown oil and exhausted to, leave the record and the sensing area free from such matter as is likely to impair the proper actuation of the sensing devices.

Fig. 1 is. an enlarged sectional elevation view through one pneumatic sensing unit.

Fig. 2 is an enlarged bottom View showing the air openings.

Fig. 3 is a side View of a pneumatic sensing unit.

Fig. 4-. is an end view of a pneumatic sensing unit showing the air intake port.

Fig. 5 is a plan view of a pneumatic sensing unit.

Fig. 6 is a side View of a sensing unit showing the side opposite that shown in Fig. 3.

Fig. '7 is a sectional elevation View taken through the air valves which admit the compressed air to the two sensing units.

Fig. 8 is a projected plan view of the two air valves and the magnet controlled interposer operator therefor.

Fig. 9 is a projected plan View of the two valve operating interposers shown with the valves removed.

Fig. 10 is a sectional elevation view taken through the middle of the card feed drum.

The invention is disclosed as embodied in an alphabet printing tabulator of the kind shown generally in United States Patents 2,079,418 and 2,199,547. These machines are controlled by perforated record cards and the purpose is to accumulate separately the amounts represented by groups of the records and also print bill forms or other accounting records. Heretofore, a plura ity of perforated cards, one for each address line and one for each item, were needed to print a record such as a bill. Now, instead of usin several separate cards for the related data, allmay be represented on one card and in different fields of said card and detected successively by passing the card repeatedly under pneumatic sensing means.

The air is driven through a filter by a pump and directed into an air pressure supply tank, and from there it passes two control valves VI, V2, Fig. '7, and along two hose branches into two pneumatic sensing units U and L. These units correspond generally in position and purpose with the usual double line of electrical sensing brushes UB and LB found in most tabulators and here replaced by the pneumatic units. Each unit has a row of air openings or ports which are aligned with the columns of data perforation positions of the record cards. The two sensing units are supported on an arcuate rockable frame which can be moved back for inspection, but is normally held with the two lines of ports over the periphery of a hollow perforated drum D. A pile of cards are placed in the magazine M from which they are picked off one at a time and transferred to the drum D. The drum has clips for holding the card thereon for about 180 of the drum movement, during which time the card is passed under the upper unit U and then under the lower unit L before being transferred to a stacker drum.

Upon the appearance of a card perforation under an air port (at a time determined by the location which is indicative of a particular letter or number value), air is allowed to escape into the drum D and, in so doing, a piston in unit U or L closes related contacts. Unit U is used as a control station for special heading card detection and group number control, while unit L has its contacts in series with add and print control devices. The air blown into drum D with lint and dirt is expelled through an exhaust pipe or hose leading away from central tube I 86.

Cards with more than one field of data indicia have "a special digit perforation which is sensed as the card passes under the ports of the upper sensing unit U. Later, as the same card passes under the lower sensing unit L, devices under control of the special perforation reverse the motion of the drum D and rock it back and forth a number of times determined by the magnitude of the digit.

The card guides Although the front end of each record card assembled on the sensing drum D is held thereon by the grippers, the other portions of the card are free and would tend to spring outward and abut against various mechanisms near the periphery of the drum. To eliminate such card contact outside the drum area, a pair of arcuate card guides are provided to confine the card path to a narrow arcuate space concentric with the periphery of the drum. Two guides IT! and I'IB, Fig. 7, are proportioned to cover the areas between. the upper and lower sensing station, and the area between the lower sensing station and stacking control means respectively. Guide ITI is fixed to a pair of rods I13 and I'M extending across the space between the two side frames. The second guide I78 is mounted in. a similar fashion between a pair of rods I15 and I15 borne by the side frames.

The card carrying drum Drum D is a hollow cylinder, the ends of which are closed by heavy annular rings I80 and IBI (Fig. secured to flanges just inside the ends of the drum. The two rings are seated on the long perforated tube I86 which Q iQIidS t l'o g l and is affixed to both side frames 42 and 43, the left end being solid and having an extending por tion 89 beyond the outer surface of frame 42, and the right end extending beyond frame 43 to hold a hollow elbow It? to which is assembled the hose or exhaust tube to carry off the lint, dirt, etc., blown through the perforations I 88 in the tube The tube IE6 is held in position axially by means of a collar I89 held thereon by a set screw between frame 43 and a hub I953 on ring I8 I. The left end of tube I526 passes through a bushing iEII on frame 42. Formed on the left end of the tube is a bearing shoulder I26 out of which extends the shaft 89 used as the picker clutch shaft. However, movement of drum D is independent of the movement of clutch shaft 89. Tube I36 is held fixed and the drum rotates thereon by means of bearing rings I93 and I94 fixed to the inner openings of end pieces I and NH.

The periphery of the drum D is divided into four arcuate segments, i. e., four areas between the sets of grippers I iI (Fig. 7). In each of these areas, the drum is perforated with columns and rows of openings, each of which corresponds to an index point on the record card. Since the card taken for purposes of illustration is the ordinary card, alphabet data is represented by a twelve hole code. To correspond with the spacing of the card indicia representations, each of the four drum areas is perforated with eighty columns of holes I95 (Fig. 1) with twelve regularly spaced holes in each column. In other words, between sets of card grippers on drum D there are twelve holes I95 in an arcuate formation, and horizon= tally displaced across the drum are eighty such formations. These drum perforations are so placed with respect to the set of grippers I4I which precedes them in the counterclockwise direction that they match the location of all the card perforation positions. Therefore, while a card is on the drum, underlying each of the card perforation positions is a drum opening to allow free passage of air under pressure through the card indicia perforations. On the other hand, all imperforate card index points cover all the other drum openings and prevent air from being blown through them.

The card gripper operating mechanism It is already mentioned that the sensing drum D contains four sets of card grippers I4I, Fig. 7, which are equally spaced around the drum to grasp the cards as they are issued successively out of the magazine M. Reference to the broken sectional view (Fig. 10) shows three of the five grippers arranged across the drum in each set. Each gripper is rectangular in formation and projects upward through a rectangular opening in the periphery of the drum, said five openings being slightly smaller than the heads I42 of the grippers. The lower part of each gripper MI is formed with a foot I9! which acts as a pressing point for one end of a pressure spring I98, the other end of which contacts with the inside of the drum.

All five grippers of a set are supported within an L-shaped formation 2M3 extending across the inside of the drum D and providing sliding surfaces for guiding the reciprocating movements of the five grippers MI. Extending across the entire drum and projecting through openings in the end rings I89 and I8! of the drum is an operating bar 20I which is seen in Fig. 7 to be shaped in the form of a Z with a lower extension underlying all five grippers .1 of one set. It is through operation of the b r and this extension that t grippers are. lifted in unison to receive a record card out of the magazine. Bar 2.0.! is also formed with an upper stopping protection which abuts against a shoulder on the angular formation 200. The bar is confined betweenv the abutting lug of formation 200 and the sides Of. the grippers Ml, but it is free for radial movement away from the center of the drum, and it is with such movement that the grippers are operated.

The four operating bars 201 are operated successively in two of the positions assumed by the sensing drum as it rotates in card feedin opera-.-

tion. The one gripper operating position is that provided for reception of cards as they come out of the magazine, and the other gripp r p rating p sit on is at enc untered after sensin is completed under the two sensing units and the card is about to be put in the stacker.

c dfe 'd drum rotating m chanisms.

The card feed drum D is rotated and oscillated by means of pawls engaging notched disks or ratchet wheels attached thereto. Certain of the pawls operate to. rotate the drum in the forward card feed direction as long as ordinary detail cards are presented. Other pawl mechanism is provided to reverse the direction of the drum movement and oscillate it a selected number of times for heading or cross footing card control to read several selected number of fields of data or repeatedly sense one field on each card. The reverse pawl mechanism is under control of a special heading digit perforation which is also by virtue of its value a cycle control perforation for selecting a predetermined number of drumreversal operations, the number of reversalsneeded depending on the number of fields of information to'be recorded or added.

In Fig. 10, it is seen that attached to the left end of drum D is a set of three spaced ratchet disks or wheels 219, 228 and 221. Disk 220 is used for the reversal movement and the other two disks are used for initial and terminal forward feed movement.

Sensing unit supports The sensing units U and L are mounted on a swinging frame which can be tipped back so that about one-half the periphery of drum D may be exposed for cleaning and inspection.

Both main side frames 42 and is are formed with upwardly extending ears for holdingthe sensing unit frame. Facing these cars and held thereto by a shaft is an ear (not shown) on a rockable frame member 343 which is a right side frame for the sensing units. Frame 343' and the companion frame on the left side are mounted in the same fashion on the main side frames 42 and 63.

When the frames are rocked to the home position wherein the sensing units are effective, a fiat portion of each frame rests on a shelf formed near the tops of the side frames. The sensing unit frames are locked in place by a pair of latches pivoted on the outer faces of the frames. With the sensing units in the exposed position, access is also given to the surface of drum D, so that all parts related to the sensing operation can be inspected, cleaned and adjusted.

Reference to Fig. 7 shows that both pneumatic sensing units U and L are shaped generallyas rectangular bars of about the same length as drum D; and they are placed between the side frames to. correspond with the axial position of the drum. {Since both units U and L are similarly constructed and mounted in the rockable frame, description of either one applies to the other.

Attached to, the right of unit; U is a hollow hose fitting- 340. Fig. 3, for receiving the flexible hose 3 Fi 7, which conveys the air- :under pressure from a pump to the sensing unit.

The. sensing units are suspended within, the rockahle, frame 342., 34.3 by parallel links. which be operated to raise the units before the gripper heads hi2 pass underneath them. Normally, the sensing units are lowered into contact with the card surface which is moving in an rec-ate path. A virtual air seal is provided between. the. air Port openings and the contacting card urface. However, while passing beyond the index points near the mar in of the card at. the botto-nnand over to thcedgeof the next card where the grippers v ngage it, it is not necessar to preserve the seal because the sensing air pressure is not then applied and therefore. the. units may be lifted to Provide clearance for the ripper heads.

Extending across the rock-able frame (Fig. Fl) .18 a pair of suspending shafts 34.5 and 34S and a pair of Operating shaf s 3e? and. see for controllingthe lifting of; the units U and L. Attached to shafts 341, 348 are. pairs of arms. 349. carrying rods .350 which are also encircled by cars. 35! extending from the sensing; units. iPivoted on the shafts 345., 345, are the ends of a pair of links 35.2 which at the other ends encircle shouldered studs 353 extendin from the side walls of the sensing units. coil. spring wrapped around shaft 345 and confined by a collar thereon. Thespring is wound to exert rotary force and is caught on th top of link 352 to urge it and unit U downward in a clockwise direction about shaft. 345. A similar spring is. assembled on shaft 3 46 to urge unit L downward.

With pairs of links 3&2 and arms 349 as the supporting means, each sensing unit is mounted for movement radially with respect to the center of drum D. Springs tend to hold the units inward in. constant contact. with the card surface. Adjustably secured to. shafts 3.50 are pairs of eccentric collars in contact: with the fixed support rods I13 and H5 near the inner ends of the two sensingunits. These collars determine the exact inner positions of the units and the degree of: closeness the units have with, or the required pressure upon, the card surface. By turning the eccentric collars and fastening them in selected an ular positions, the inner ends of the sensing units can be positioned as desired on or above the card to eliminate excessive air leakage. An air pressure of from 3, to 10 pounds may be used with e#- as, a desirable value.

Although the springs tend to hold the sensing units in the effective card reading position, a positive disengaging means. is provided to lift the units: together for a portion of eachcycle. Since the. units are. spaced exactly at a interval circumferentially of drum D, which is alsothe interval from card to. card thereon, an action for lifting one unit for clearance of the gripper heads may be taken simultaneously with the lifting of the other unit.

The. pneumatic sensing units Each of the sensing devices U and L may be considered as a unit, for it is removable for replacement and inspection. Units .U and L: are similar construction so that the description which.

follows applies to either structure. The purpose of th pneumatic unit is to direct separate jets of compressed air, one jet for each card column (80 in the disclosed embodiment) against the index point positions of a moving card. In all the imperforate positions of the card, the air is confined and ineffective. However, as soon as a data representing perforation appears under a jet, the air escapes therethrough to pull with a vacuum action on a piston in the stream of the air. Connected to the piston are contact closing devices for sensing an electrical impulse which is timed to correspond with the data value which is determined by the position of the perforation in the card column. In the case of alphabetic data, two perforations are placed in code positions in a single column to represent a letter, and two differentially timed impulses are initiated by the same pneumatic sensing controls.

Figs. 1-6 show various views of a pneumatic unit. A number of bars extend th full length of the unit and :are assembled between side plates 369 and 310 which are formed with the supporting cars 35! and carry studs 353 for supporting links 352.

A set of four metal bars -31I-314 are fastened between the end plates 369 and 310. These bars are accurately machined and fitted closely together with air tight joints because they are formed with tubes, cylinders and air chambers for carrying and confining air under pressure. The one central bar 312 is formed with a set of eighty grooves which, when the bars 312 and 313 are assembled face to face, are blocked off to provide eighty rectangular port openings 316 (Fig. 2) corresponding in size and spacing to the arrangement of columns of data'perforations on the card. There is a port 316 for each column of index points on th card, and the unit is located to match the ports with the card columns as they appear directly above the sets of openings I95 in the drum D carrying the card. The lower ends of bars 312 and 313 are beveled down to a smooth blunt end designed to ride on the surface of passing cards.

The top of each rectangular tube or port 316 (Fig. 1) is blocked off and sealed because the groove of which it is composed does not extend to the top of bar 312.

Leading off from each of the vertical tubes 316 is a horizontal cylindrical opening 311 with constricted holes between the two. There are forty such openings 311 in bar 312 and they are arranged in two rows and staggered in position along said rows. A similar number of cylindrical openings 31'! are cut into bar 313 where they are also arranged staggered in two rows.

In each of the eighty openings 311, 311 is a piston comprising a disk-shaped piston head 319 and a long rigid piston rod 380 fastened thereto. Attached to the ends of the rods 383 are insulation buttons 381a, 3811), 38lc and 381d, which are designated differently to distinguish the rows and tiers of pistons and the order in which they are arranged across the unit. It is apparent from the positions of buttons 38la38id that not only are the pistons arranged in four rows but the rows are divided into two tiers wherein the pistons are reversed in position, so that the buttons 381a and 38Ic of the two top rows of pistons project at the right, and the buttons 38!!) and 381d of the two bottom rows of pistons project from the left of the unit. Rods 386 slide in holes in the bars to guide the pistons.

With the Pistons arranged as shown, it is possible to make the working parts of substantial size and durable formation while leading to the port openings 316 which are necessarily of restricted size and close formation as determined by the card index point and column proportions.

Behind the upper tier of pistons is an air inlet chamber 383 and there is a similar chamber 384 behind the lower two rows of pistons. Chamber 383 is formed by cutting a wide groove almost the entire length of bar 31!, one end being sealed and that is the end near the side plate 310 (Fig. 3). The other end of chamber 333 is not sealed, because plate 369 (Fig. 4) is formed with a rectangular opening 383' leading into the trapeziumshaped inlet hose fitting 340 which is clamped to plate 369. The other chamber 384 is formed in a similar fashion in bar 314 and coincides with a hole 384' in plate 369 to communicate with the inner opening of the air hose fitting 340.

In chamber 383 (Fig. 1) there extends a shouldered end of the piston assembly. This end abuts against the side wall of the chamber and acts as a limiting stop for the piston 319 which is spring urged toward the left to the home position as shown.

Piston 319 is not fitted closely in the cylinder 311 but instead has considerable clearance so that the air is allowed to flow from chamber 383 to cylinder 311 and build up equalizing pressure in front of the piston quite rapidly after the piston is actuated. In the normal condition of the parts, with piston 319 positioned as shown, air under substantially equal pressure is present in chamber 383, behind the piston in cylinder 311, in front of the piston, and all the way down tube 316 to the port obstructed by the surface of a card.- Should there be a slight leak of pressure at the port due to an imperfect seal with the card surface, such a drop in pressure would not be sufficiently abrupt to cause piston actuation. However, when a data representing card perforation appears under port 316, there is a sudden release of the air under pressure through tube 316, the card and a drum opening I95.

The air in cylinder 311 and tube 316 in front of piston 319 is free to move while the air in chamber 383 behind the piston is restricted in movement by the presence of the piston. The result is that the air escaping through the card perforation causes a lowering of the pressure in front of the piston amounting to a vacuum or partial vacuum in the cylinder 311. For a moment this condition exists until the air behind the piston tries to fill the lower pressure area and in so doing moves the piston and the connected rod 386 toward the right.

As explained hereinafter, a contact establishing spring presses against the right end of the piston assembly, and it is this spring pressure which is overcome by the air under pressure. Movement of the piston to the right is of sufiicient duration to establish contact before the air passing around the clearance between the piston and the cylinder wall reaches the lower end of tube 316 and abuts against the card surface and tends to equalize the air pressure before and behind the piston. When such a point of equilibrium in pressure is about to be reached and before it is reached, the spring urging the piston assembly to the left becomes effective to restore the piston and at the same time break the contact which is established by movement toward the right.

It is necessary for the actuation of the piston and the resulting electrical contact to be extremely rapid, because there are instances when two perforations in a card column are found directly adjacent each other, and separate impulses must be created by successive actuation oi. the piston under control of the two perforations appearing one right after the other on the rotating drum under the pneumatic port. For this reason it is important that the size or area or the tube 316, the holes leading from the cylinder 31'! into the tube 376 and the clearance between the piston 37S and the walls of cylinder 3'11 be so proportioned that the right amount of time is allowed to elapse between the actuation of the piston by the vacuum condition and the rapid resumption of pressure equilibrium which follows thereafter. It was found by experiment that the proportions between the area of the rectangular tube opening 315 and the clearance area around the piston 379 should be approximately as 3 is to 1. This proportion presupposes that there is sufficient opening between the cylinder and the tube to allow free escape of the air under pressure. The area of the piston head 319 is about 15 times the area of the port opening 316. The area of piston clearance is substantial so that, when multiplied by 1-2, it is about equal to the average volume of the air port chamber between the piston and the card. It will be noted that the advantage lies not only in the rapid initiation of an impulse upon the appearance of a card perforation but alsothe rapid recovery of the impulse creating facilities, so that rapid operations may continue under high speed conditions.

Now that the operation of the piston has been explained with reference to the action of the air pressure thereon, it is believed well to point out how such actuation is converted into the initiation of electrical impulses which are timed by virtue of the positions of the related perforations in the card on the drum. Since the adding and printing devices of the machine are synchronized with the operation of the drum, the resulting impulses are effective to control accumulation of the amounts sensed on the record card and the recording of numerical and alphabetic data also analyzed thereon.

Extending across the top of the electrical sensing unit is a pair of square insulation bars 386 and 38'! fastened between the side plates 3'69 and 310. These two bars are assembled at different levels, the upper one to cooperate with contacts controlled by the upper tier of pistons and the lower one to have association with the other half of the pistons found on the lower level. The bottom portion of each insulation bar is slotted at regular intervals in forty places to receive and hold a like number of L-shaped transmission plates 388. The vertical extension of these plates 388 are not of similar length but are seen to have two different sizes, the short length extensions being interspersed with the longer extensions the iormer provided for the upper row of pistons of each tier. In contact with the horizontal member of each L plate 338 is the p inted end 389 of a vertical terminal 390 pmjecting upward with plug openings at the upper surfaces of bars 388 and 381.

In Fig; 5 it is seen that these wiring terminals 390 are arranged in a staggered formation across the tops of the'two insulation bars. They actas receivers for plug tips on wires leadingfrom the control mechanism of the tabulator; Terminals 390 are formed hollow to receive the tips and establish contact therewith.

Extending downwardly from each terminal plate' 3-88 is a leaf Spring 39] which at its lower end fits into a notch out vertically in the button 3am fastened; to the end of the piston rod 380. Leaf spring 39! is tensioned to press thepiston assembly toward the left into the normal position,- wherein the left end of the assembly abuts against the left wall of chamber 383.. The plates 388 formed with the long vertical. extensions also carry similar leaf springs 39! in the shape of a bent wire which cooperates with the other row of buttons SB'Ic fastened to the second row of pistons in the upper tier. The plates ii fiaproj'ecting from the left bar 2'87" are similarly provided Withleaf springs 39] cooperating with the buttons 38th and 381d on the lower tier oi .pistons.

Associated with the forty leaf springs 391 at the right is a common contact bar 392 fastened to plate 374 but separated therefrom by an insulation strip 393. This bar is formed with a series of upper and lower prongs 394 and 395 extending inwardly toward the sides of 'the leaf springs 391 but normally separated therefrom. Electrical contact is established between the leaf spring 391 and prong 39E whenever the piston '37!) is shifted to the right by change of air pressure attending the detection of the presence of a card perforation. The impulse path flows through bar 392 out to prong 394 against the abuttifig lea'f spring '39] up into the terminal plate 333 and. thiO'ugh plug socket 3 to the colltiOl Wi l'- me.

In order to explain the arrangement of the pistons and connected contact springs more fully, certain Of the terminals 3 911 (Fig. 5) are further designated 39Ud-390d to point out that the succes'sive denominational or columnar orders of the sensing" device alternate from side to side of the unit a's'w'ell as being staggered in arrangement on each Side. It is seen that the 't'eiinihal 3911a is on the right side While the he'Xt termineu (i. e. he'xt with reference to lengitudihal distribution), ter: minal 39011, is on the left side, and the other two teflhifial's'iiQ'O and 3'9Ud a1so alternate from right to left. It is explained herei'r'ibefore that the buttons 3'8! d'38l (1' also alternate from side to side as well as from tier to tier; Now the effect of such arran ement may be Studied with reference to the electrical connections between spring wires or Contact blades 39'! and the prongs '394 and 95 on the common contact bars 392. The spaced and staggered buttons '38'la and 3810 (Fig. '6) in the uppertier are seen to extend from the right wall and operate wires to contact with prongs 39 i and 395, respectively; Similarly; the spaced and: stagg'ied' buttons 38117 and 3810? (Fig. 3) in the lower tierare round to extend from the left bar '3'? I' and operate wires 39! to contact with the long and short prongs, respectively. From the foregoing it maybe gathered that the electrical contact devices are made in s'turdier proportions and with greaterclearances due to the piston arrangement in staggered rows and alterhatin'g tiers.

The pressure control values It is shown in Fig. '7 that a pair of control valves is provided between the compressed air supply and the upper and lower sensing units U and L. These valves cut oil the compressed air at times when there are no cards atthe sensing stations;

A more detailed -showing or the valves and the operating mechanism therefor is given in Figs. 7-, 8 and "9. valve V] is seen to cover the opening to thetube that leads from the'main air pressure inlet 33!" to the se arate duct or tube 34] which is connected to the upper sensing unit U and conducts the air under pressure to the chambers 383 and 384 in the unit housing. The other valve V2 is seen to be positioned to close the valve opening of a cylinder which is the connector between the main air entry space 334 and the separate tube 344 that leads to the air chambers in the lower sensing unit L.

Valves VI and V2 are seated in a casing 354 secured to the rockable frame 343. The stems of the valves extend below the casing 354 (Fig. '7) and have formed thereon collars 358 against which press the ends of coil compression springs 364 tending to keep the valves closed.

The lower ends of the valve stems are poised above a pair of bell cranks 399 pivoted on studs 454 extending from a shelf 385 formed on a slide 375 attached with a screw and slot connection 382 to the main slide frame 43. Slide 315 is articulated at 419 on the top of an operating arm 45'! which is pivoted at 46! on the main frame and carrying a roller 458 cooperating with a cam 462 fixed to shaft 16.

Early in each cycle, cam 462 rocks arm 46'! in a counterclockwise direction and the arm then pushes slide 315 to the left so that the cranks 399 thereon press against the ends of the valve stems and lift valves Vi and V2. In Fig. 9 it is seen that the long arms of cranks 399 are normally directly under the stems of the valves and in position to operate them as timed by cam 462 to agree with the perforation positions on the cards, said valves being closed at times other than the index point sensing time.

Cranks 399 are used as interposers for disabling the valve lifting action and thereby cutting off the air pressure supply to one or both sensing units'for one or more complete cycles. This control is exercised under control of card levers for detecting the absence of cards at the sensing stations and thereby closing contacts to energize magnets for rocking cranks 399 to prevent valve operation when cards are missing.

In Fig. 9 it is seen that, if a. crank 399 is rocked about 30 in a counterclockwise direction, the long arm will be moved out of abutting relation with the end of the valve stem. Then, even though slide 375 reciprocates the cranks axially, the one which has been rocked fails to operate the related valve. The magnets for rocking the, interposer cranks are about to be described.

Attached to frame 43 (Fig. 8) is a bracket 464 carrying a pair of magnets VIM! and VIM2, the former being controlled by the upper card lever and the latter by the lower card lever. Associated with the magnets (Fig. 8) is a pair of armatures 4G5 pivoted at 414 on bracket 464. A horizontal armature lever extends to the left and is articulated with the flat end 475 of a call rod 411, the lower end of which is bent to project into a hole in the short arm of crank 399. Ends 415 are guided by a notched bracket 418 and the lower ends are confined by a retaining strip 456 which is forced into grooves of studs 454 and serves to hold the cranks 399 down on the pivots with just enough room between the bottom of strip 456 and the top faces of the cranks for the ends of wires, ll"! to move freely to operate the cranks.

When a magnet is energized due to the absence of a record at the related sensing station, armature lever 465 (Fig. 8) is rocked clockwise and wire 41! is pulled upward to rock the crank 399 counterclockwise (Fig. 9) and move the long arm thereof away from the end of the valve stem. Then, when the slide 315 is shifted upward, it is ineffective to cause lifting of the related valve with the result that no air under pressure is supplied to the sensing unit having no card on which to work.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In an accounting machine controlled by perforated records, a pneumatic record sensing unit comprising a body structure with a plurality of closely spaced port openings cooperating with said record perforations, said structure having separate cylinders at an angle to each of said openings and connected therewith, a piston in each of said cylinders, said structure having an air chamber leading into all of said cylinders, means for supplying air under pressure to said chamber, and electrical contact devices operated by said pistons when they move due to the escape of air from related ports through said record perforations.

2. A pneumatic sensing unit comprising a body structure with a plurality of rectangular port openings spaced in a single row at regular intervals, said structure having a series of cylinders in a staggered formation and connected to said openings, each cylinder communicating with a related port opening, said structure also having an air chamber leading into all of said cylinders, means for putting air under pressure into said chamber, a piston in each of said cylinders, and electrical contact devices operated by said pistons when they move due to escape of air from related ports.

3. A pnenumatic sensing unit comprising a frame with a plurality of air port openings arranged at spaced intervals, said structure also having a series of cylinders each of which is in communication with a related port opening, means for compressing air in said cylinders, a piston in each of said cylinders, a piston rod extending from each of said pistons and extending through said frame to the outside, and electrical contact devices operated by said extending piston rods.

4. The invention set forth in claim 3, wherein said electrical contact devices comprise a series of individual terminal plates, each of which car ries a flexible contact member, said member being in cooperation with one of said piston rods and a common contact bar also on the outside of said frame, said bar having a portion normally separated from said flexible members, whereby operation of any of said pistons causes movement of the related flexible member into contact with said common bar.

5. The invention set forth in claim 3, further characterized by the fact that a substantial amount of clearance is provided between said piston and the walls of the surrounding cylinder, the proportion of said clearance area to said port opening being as l is to 3, whereby said piston is restored quickly upon the escape of air from the port opening.

6. The invention set forth in claim 3, further characterized by the fact that the area of the piston is substantially larger than the port opening, the ratio being approximately as 15 is to 1, whereby escape of air through a port opening causes rapid actuation of the piston and connected electrical devices.

7. A pneumatic sensing unit comprising a frame with a plurality of air port openings spaced at intervals, said structure having a plurality of tiers of cylinders at an angle to said openings, each cylinder communicating with a related port opening, means connected with said frame for placing air under pressure into said cylinders, a piston in each of said cylinders and electrical devices operated by said pistons upon the escapement of air from the port openings.

8. The invention set forth in claim 7, further characterized by the fact that the different tiers of said cylinders are arranged on opposite sides of said frame and in opposite directions to the port openings arranged in a single centralized row.

9. The invention set forth in claim 7, characterized by the fact that said different tiers are arranged at different levels on opposite sides of said frame and project from the centralized port openings in different directions and at diiferent heights from the openings thereof.

10. The invention set forth in claim 7, further characterized by the fact that said tiers each comprise a plurality of staggered rows of cylinders, said tiers being arranged not only on opposite sides of said frame but also at different levels, whereby the row of port openin s c mmuni ate with cylinders on both sides of the frame at different levels or tiers and rows of cylinders arranged in staggered formation within the tiers.

11. The invention set forth in claim 7, characterized by the fact that the cylinders in said plurality of tiers are arranged in a staggered formation therein and said tiers are placed on opposite sides of said frame at different levels and further characterized by the fact that the port openings are connected thereto alternately with one port opening communicating with a, cylinder in one tier and the next port opening communicating with a cylinder in the other tier.

12. The invention set forth in claim 7, characterized by the provision of four rows or cylinders arranged in two tiers, the two rows of cylinders in each tier being arranged in a staggered formation therein, said tiers being arranged with the cylinders on opposite sides of said frame and at different levels therein, said port openings communicating with said four rows of cylinders alternately with respect to the difierent tiers and rows, whereby a space is provided for each cylinder opening four times that of the space provided for each port opening.

13. A pneumatic sensing unit having a. frame composed of four rectangular bars connected to form a single unit, one of the inner or centralized pair of said bars being formed with a series of facing grooves to form a row of port openings, said centralized pair of bars also being formed with a plurality of tiers of circular openings arranged in staggered formation at right angles to said port opening grooves and communicating therewith to furnish individual cylinders for the port openings, the two outer pairs of bars being formed with inner longitudinal grooves comprising air chambers communicating with all cylinders, means for supplying air to said chambers, pistons in said cylinders, and electrical devices operated by said pistons when air is allowed to escape through any of said port openmgs.

14. The invention set forth in claim 3, characterized by the fact that the electrical contact devices include a flexible member in cooperation with said piston rod to force an extending end of said piston into an abutting relation with a wall of said frame, whereby the electrical contact de vice serves a dual purpose in restoring said piston and establishing contact.

15. In a machine controlled by perforated paper sheets, a pneumatic sensing unit contacting the surface of said sheets, means for advancing said sheets with respect to said sensing unit, said sensing unit comprising a frame structure formed with a plurality of port openings ending directly on the surface of said sheet, said frame also formed with a plurality of cylinders each communicating with one of said port openings, a piston in each of said cylinders, an air chamber in said frame, means for supplying air under pressure to said chamber and in said cylinders behind said pistons so that the appearance of the perforation causes the escape of air and the movement of a related piston toward the port opening, electrical contact devices operated by movement of the pistons whereby the movement of the air away from the pistons and contact devices causes the removal of lint and dirt in a directlon away from the mechanism.

16. The invention set forth in claim 3, further characterized by the substantial area of clearance provided between the piston and the cylinder ,said clearance area multiplied by 12 being equal to the average volume of the port space between the piston and the air port opening.

FRED M. CARROLL. OSCAR L. HIBBARD.

REFERENCES CITED The following references are of record in the file of this patent:

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