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Title:
Record projector
United States Patent 2220885
Abstract:
This invention pertains to printing telegraph apparatus and more particularly to devices of this type in which a considerable portion of a recorded message is to be displayed at any time for observation at a distance. The principal object of the present invention is to provide in a recording...


Inventors:
Burcky, Charles W.
Application Number:
US24630338A
Publication Date:
11/12/1940
Filing Date:
12/17/1938
Assignee:
TELETYPE CORP
Primary Class:
Other Classes:
353/47
International Classes:
G03B21/134
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Description:

This invention pertains to printing telegraph apparatus and more particularly to devices of this type in which a considerable portion of a recorded message is to be displayed at any time for observation at a distance.

The principal object of the present invention is to provide in a recording apparatus a paper feeding and display device which maintains a substantially continuous tension in the paper strip between the platen and the paper take-up reel.

Another object of the invention is to provide in a record projector, means for facilitating the shifting and unshifting of the exposed area without bulging the paper strip or disturbing the focus of the projection.

In a preferred form of the invention, the message display device comprises a recording telegraph printer, of any conventional type and preferably of the page printer type, in which the recording paper is advanced by line feed movement of the printer platen. The device comprises a paper backing plate, which is located just above the platen and which is inclined slightly to the rear. Incidentally, the height of the plate is such that at least eleven printed lines, spaced at double line feed, may be exposed on the paper which is immediately in front of the backing plate.

After the paper passes around the platen and in front of the backing plate, it is gripped between feed and pressure rollers located at the upper end of the backing plate, the feed roller of which is driven by a belt through power derived from the main operating shaft of the printing apparatus. After passing between the feed and pressure rollers, the paper is fed around a paper takeup spindle which is also driven by a belt from the same source. These belts cooperate with pulleys mounted on a power-take-off shaft which derives its power, through a belt, from the main shaft of the printer.

One of the features of the invention resides in the fact that the suplort for the paper backing plate is so designed that the backing plate is in the same plane when the -platen is located in either the upper or the lower case position, so that the exposed area may be "shifted" and "unshifted" without bulging the paper or disturbing the focus of the projecting apparatus. By providing the above-mentioned feeding mechanism, having a continuous torque, in addition to the usual line feed mechanism, the exposed area of the record strip is always kept taut between the paper platen and the feed roller at the upper end of the paper backing plate. Also, with the arrangement according to the present invention, the paper backing plate is movable up and down substantially in its own plane during the shifting operation, so that an accurate focus may be maintained in both upper and lower case positions. A better understanding of the invention may be had from the following description taken in conjunction with the accompanying drawings wherein, Fig. 1 is a side elevational view of a printing :0 apparatus embodying the paper feeding and display arrangement of the present invention; Fig. 2 is a plan view of the apparatus shown in Fig. 1 with parts broken away to show features of the present invention; Fig. 3 is a vertical cross-sectional view taken substantially on lines 3-3 of Fig. 2; Fig. 4 is a fragmentary plan view taken substantially on line 4-4 of Fig. 1; Fig. 5 is a fragmentary end view of the platen unit to show part of the line feed and platen shifting mechanisms; and Fig. 6 is a vertical cross-sectional view of the general structure of the projecting device showing diagrammatically the optical arrangement therein.

In the accompanying drawings, like reference characters indicate similar parts throughout the several views. For a complete understanding of details shown in the drawings but not de- 80 scribed herein and which form no part of the present invention, reference may be had to U. S.

Patent No. 1,904,164 issued April 18, 1933, to S.

Morton et al.

Having reference to Fig. 6, the projector with which the printing apparatus embodying the present invention is employed comprises a general structure having a lower compartment 11 and an upper compartment 12 supported directly above the lower compartment by means of four posts 13. The lower compartment II contains the telegraph printer, indicated generally as 14, which is of the type disclosed in the aforementioned patent and which embodies the display and feeding devices according to the present invention. The recording strip 15 is indicated as extending from the supply roll 16, over the backing plate 17, thence to the take-up reel 122. Contained also within the lower compartment 1 are certain parts of the optical system; namely, the viewing mirror 19, the objective lens 21 and the illuminating lamp 22. The upper compartment 12, which is open at the bottom contains a large mirror .23 and a screen 24 of tran"' .cent 85 material for displaying the image of the record on strip 15.

Having reference to Figs. 1, 2, 3, and 4, a printing apparatus to which the present invention is applied comprises a typing unit (shown generally in section in Figs. 3) which includes a primary selecting mechanism, indicated generally as 25 (Fig. 4), which is of the sword-and-T type disclosed in U. S. Patent No. 1,745,633 issued to S. Morton et al. (fully disclosed in the firstmentioned patent), and a secondary selector or selector vane assembly, indicated generally as 26. The selector vane assembly 26 controls, through a series of bell cranks 27, a corresponding series of curved code bars 28 carried in a movable type carriage. As set forth in the firstmentioned patent, this type carriage, indicated generally as 29, is movable longitudinally with respect to a stationary platen 31. The type car'0 riage 29 also carries a ribbon feed mechanism, indicated generally as 32.

Referring particularly to Fig. 4, a motor 33 supplies power through its pinion 34 and a worm gear 35 to a main operating shaft 36 which carries the spacing mechanism, indicated generally as 37, and the selector cam assembly indicated generally as 38. As is fully disclosed in the first-mentioned patent, power is communicated from the motor 33 to an operating cam assembly through a grab clutch, such as shown at 39.

Driving portion 41 of grab clutch 39 constantly rotates with the shaft 36, which has also frictionally connected thereto the spacing mechanism 37 and the selecting cam assembly 38. Portion 41 is cooperatively engageable with the driven portion 42 (which is splined to the operating cam assembly) when throwout lever 43 is operated in timed relation with the reception of code signals.

The spacing mechanism 37, by means of its escapement pawls 44 and the escapement ratchet 45 (fully described in the first-mentioned patent) controls, through the worm gear 46, a gear 47 which, through shaft 48, gear 49, and rack 51 (Fig. 3), controls the movement of the type carriage 29.

Upon receipt of signal code combinations the primary selector mechanism 25 responds thereto and controls, through elements 52 (Fig. 4), the selective setting of vanes 26. As described in the first-mentioned patent, this setting of vanes 26 is transferred to the curved code bars 28 through the instrumentality of beli cranks 27.

The setting of the code bars 28 permutatively causes an alignment of notches to occur opposite one of the pull bars 54. As previously mentioned, the operation of the primary selector cam assembly 38 causes the clutch throwout lever 43 to be operated to permit the operative engagement of grab clutch 39 and the rotation of the operating cams. A cam 57 (Fig. 3) controls a function lever bail 56, and a printing bail 58. Printing bail 58 is operatively articulated (as described in the first-mentioned patent) to a pull bar operating bail 59, so that when one of the pull bars 54 falls into an alignment of notches in code bars 28, the pull bar bail 59 (which is reciprocated when the printing bail 58 is oscillated) will engage (through its blade 61) the hook portion 62 of the pull bar 54. Thus, the pull bar 54 will be actuated leftwardly, as viewed in Fig. 3, against the action of its springs 63 to operate its associated type bar 64, through its gear and rack articulation therewith, in a clockwise direction to bring the type face against the platen 31.

The selector vanes 26 also control a series of function levers 65 which control the various functions, such as line feed, platen shift, and platen unshift, which are especially identified with the present invention. The function levers 65 are pivotally mounted on a common pivot rod 66 and are adapted under certain selective conditions to be rocked in a counterclockwise direction against vanes 26 by a spring 67. However, the function levers 65 are held against action by spring 67 by the function lever bail 56. Upon rotation of the cam 57 in timed relation with the selective operation, the bail 56 is oscillated, and through the cooperation of rod 68 with arm 69, the function lever selected will be actuated by its spring 67 into registrable engagement with the selector vanes 26 to effect (as fully described in the firstmentioned patent) the operation or performance of the function assigned to the particular function lever 65 selected. A ribbon oscillating bell crank 71 is pivoted at 72 on a lever 13 in order that the ribbon shall retain its relation to the platen in both the upper and lower case positions, as fully described in the first-mentioned patent. In this manner it is insured that the printing will be equally visible to the projecting system whether the recording operations be in the upper or the lower case position.

In accordance with the present invention the guiding and display means for the paper strip has been attached to the platen structure in order that the paper may form an area for simultaneous projection and display of several recorded lines, including the line being printed. This arrangement will now be described.

Platen 31 is rotatably carried on shaft 74 mounted in a platen frame comprising the rail member 15 (Fig. 3), and a pair of side members 76 and 77. The platen frame is pivotally mounted on the side frames 78 and 79 of the printing apparatus at pivots 81 and 82. Fixed to one end of the platen 31 is a line feed ratchet 83 (Fig. 2), and having reference to Fig. 5, the platen side frame 77 is shown pivoted at 82 to the printer side frame 79. The upper end of a line feed link 84 is pivotally connected at 85 to arm 86 of a line feed bell crank lever 87, which in turn is pivotally supported at 88 to the platen side frame member 76 (Figs. 2 and 5). Pivotally connected to the end of arm 89 of line feed lever 87 is a line feed pawl 91 which cooperates with the line feed ratchet 83. As previously mentioned, special function levers 65 are provided for the various functions, such as line feed, platen shift, and platen unshift. Accordingly, when the line feed function lever 65 is selected for operation, it controls through mechanism shown and described in the aforementioned Patent No. 1,904,164, the reciprocatory movement of the link or rod 84 (Fig. 5). Now, during the line 0o feed operation, the link 84 is lowered, causing the line feed bell crank 87 to be actuated in a clockwise direction to cause the pawl 91 to be moved toward, the right (as viewed in Fig. 5) to engage a tooth on ratchet 83, to rotate the platen 31 one step in a line feeding direction. When. the rod 84 is raised, counterclockwise rotation is imparted to t-e lever 87 and leftward motion is imparted to the pawl 91 in preparation for a succeeding line feed operation. As disclosed in Patent No. 1,904,164, provision is made to permit, if desired, the advancement of the platen through an angle equal to two teeth for double line-spacing.

To permit the shifting of the platen 31 from its upper case to lower case position and vice versa, special function levers 65 are provided, which are operable in accordance with the disclosure in Patent No. 1,904,164 to control the S movement of a link 92, the upper end of which is shown in Fig. 5, as pivotally connected to side frame 77 of the platen frame assembly. For example; assuming that the platen 31 is in a position to print lower case characters and it is desired to shift the platen so as to print upper case characters, the rod or link 92 will be actuated downwardly causing the platen frame to be rocked clockwise to raise the printing point on the platen 31 to receive impressions from the upper row of characters on the type bars 64. Conversely, when it is desired to return the platen to its lower case position, upward movement will be imparted to the rod 92 to cause the platen frame to be rocked counterclockwise, thus bringing the printing point in alignment with the lower row of type on the type bars 64.

Fixed to each of the side frames 76 and 77 of the platen frame assembly is a bracket 93 (Fig. 1). To the extremity of each bracket 93 is pivotally articulated a laterally disposed lug 94 at each end of the bottom edge of the backing plate 17 in such manner as to dispose the bottom edge of the backing plate 17 substantially tangential to the platen 31 at the line being printed. Preferably, the plane of the front surface of the backing plate 17 is positioned slightly forward of the true tangential plane to insure that the paper 15 is drawn against the backing plate.

Fixed at points 82 and 95 of the printer side frame 79 is a bracket member 97. Similarly, secured at points 81 and 70 of printer side frame 18 is a corresponding bracket member 96. Each of the brackets 96 and 97 is provided with an upstanding lug 98 and 99, respectively, at the upper end of each of which is pivotally articulated one end of a bar 101 and 102, respectively. At the opposite ends of bars 101 and 102 are pivotally connected laterally disposed lugs 103 at each end of the upper edge of the backing plate 17. In this manner, a parallel motion device having its cen4ters at 80, 82, 90, and 100 is provided, so that the backing plate 17 is mounted for movement during the shifting and unshifting operations substantially in its own plane so that an accurate focus may be maintained in both upper and lower cases.

The paper roll 16 (Fig. 3) is mounted at the rear of the printing apparatus between the printer side frames 78 and 79 and is supported on 5 a spindle 105, which is suitably journalled in said side frames. When introducing the paper 15 from the paper roll 16 into the platen unit, in a well-known manner, the paper is passed over a paper tension bar 16 suitably mounted at the ex30 tremities of corresponding arms 107 of a pair of bell crank levers 108 pivoted at points 109 on the platen side frames 76 and 77. To the extremity of the depending arm of each of said bell crank levers 108 is attached one end of a spring I 1I, the 35 other end of which is secured to the platen side frames 76 and 77. Thus, during the sudden line feed movement of the paper 15, the springs III are stretched, thereby absorbing the sudden jerk imparted to the paper and preventing such rapid ro movement from reaching the paper roll 16. Then, immediately following the line feed operation, the springs 1II contract until levers 108 strike against the stops 110, thereby smoothly unrolling paper 15 from the paper roll 16.

r5 Pressure rollers 112 serve to press the paper against the platen 31, so that the paper will be positively fed along every time the platen is rotated a step for line feed in response to the line feed signal. The paper 15 is then passed behind the color ribbon (supplied by the ribbon feed 8 mechanism 32) at the line of printing. In the printing operation, the ribbon guide 113 is reciprocated up and down through the medium of the lever 71 each time the pull bar bail member 59 operates a type bar 64. The record strip or paper 15 is then fed across the backing plate 17, which, as previously mentioned, is substantially tangential to the platen 31 at the line being printed, for exposure to the optical system (as indicated in Fig. 6) of several 18 lines of the message, including the line being printed. The record strip 15 is then passed over a guide roller 114 (Fig. 3), loosely mounted for rotation on pilot screws 100 (Fig. 1). The paper is then passed around a roller 115 secured to a 20 shaft 116, which is journalled in the plates 101 and 102. Associated with roller 115 and disposed on the opposite face of the paper 15 is a pressure roller 117 carried on a pair of bell cranks 118 (one of which is shown in Fig. 3). A spring 119 acts 25 upon bell crank 118 to supply the pressure between rollers 115 and II7, which pressure is sufficient to establish frictional cooperation between the paper and the rollers. The paper 15 is then passed under a cross bar 121, extending between 30 brackets 96 and 97, to a paper take-up reel, indicated generally as 122, carried on a shaft 123, journalled in the brackets 96 and 97.

As shown in Fig. 4, there is fixed to shaft 36 a grooved pulley 124. Secured to the side frame 79 35 of the printer is a stud shaft 95 (which also forms one of the means of securement of bracket 97 to frame 79) on which are rotatably mounted three grooved pulleys 126, 127, and 128 (Fig. 2) which are fixed to a common sleeve (not shown) carried on shaft 95. Pulley 124 is connected to pulley 128 by a belt 129. A pulley 131 is loosely mounted or carried on an extended portion of shaft 116 (Fig. 2), and fixed to said shaft adjacent to pulley 131, and separated therefrom by a' disc of friction ma- 4 terial 132, is a collar 133. Adjacent to pulley 131, and oppositely disposed to disc 133, is a disc 134, and interposed between pulleys 133 and disc 134 is a disc of frictional material 135. Carried at the end of shaft 116 is a compression spring 136 60 disposed between a washer 137 and the disc 134.

The pressure exeerted by spring 136 of this friction clutch arrangement is adjusted by a nut 138, and in this manner, pulley 131 is frictionally connected to shaft 116. Pulley 131 is connected to B5 pulley 127 by a belt 139.

A pulley 141 is fixed to the extended end of shaft 123 and is connected to pulley 126 by a belt 142. A flanged collar 143 is secured to shaft 123 adjacent to the take-up reel or spool 122, and no interposed between the flange of collar 143 and hub 144 of reMl 122 is a disc of frictional material 145. Also, contiguous to hub 144, but oppositely disposed to disc 145, is a disc of frictional material 146 which is compressed between hub 144 and a 65 disc 147. A slotted disc compression spring 148 is carried on shaft 123 between disc 127 and a disc 149. The pressure exerted by spring 148 of this friction clutch arrangement is adjusted by a nut 161 and in this manner the take-up reel 122 is 70 frictionally carried on shaft 123.

During the operation of the apparatus according to the present invention, shaft 36 is continuously rotating due to power imparted to it from the motor 33. Accordingly, through the instru- 7y mentality of pulley 124 and belt 129, continuous rotation is imparted to pulleys 126, 127, and 128.

Consequently, through pulley 127 and belt 139, constant rotation is imparted to pulley 131. Likewise, through pulley 126 and belt 142, continuous rotation is imparted to pulley 141. The friction clutches (previously described) comprise the torque imparting medium between pulleys 131 and 141, and shafts 116 and 123, respectively. Now, since the feeding of the paper 15 from the supply roll is controlled by the line feed mechanism of the printer, the constant torque imparted to shaft 116 (and hence to roller 115) acts, through the instrumentality of pressure roller 117, to keep or maintain the paper 15 taut between platen 31 and roller 114. By rotating the roller 115 continuously, the slack in the paper 15 caused by a line feed movement is immediately taken up, thus preventing the paper 15 from bulging between rollers 114 and platen 31.

Due to the constant rotation of pulley 141, and hence shaft 123, a constant torque is applied to the take-up reel 122 by means of the friction clutch associated with said take-up reel. In this manner, the paper 15 is maintained in a taut condition between the rollers 115 and 117, and the take-up reel 122.

With the arrangement of belt driven paper advancing devices according to the present invention, the paper 15 is constantly maintained in a taut condition between all of the gripping points, and bulging and/or unnecessary oscillation or vibration of the paper is prevented, thus producing a better and more steady image of the printed record on the projection screen. Furthermore, with the arrangement according to the present invention, the platen 31 may be shifted and unshifted readily without disturbing the tautness of the paper 15.

Although a particular embodiment of the invention has been described herein, it will be understood that the apparatus is capable of many modifications, and it is contemplated that all changes which come within the range and scope of equivalency are intended to be embraced within the purview of the appended claims.

What is claimed is: 1. In a strip feeding and display device, a platen, case shifting means therefor, platen feed mechanism to advance intermittently a strip for display of a substantial area of its surface, a second feed mechanism spaced apart from said platen feed mechanism, a re-wind mechanism, a single power shaft for supplying power to all of said mechanisms, yieldable means for transmitting energy from said shaft and for driving said second and third recited mechanisms to maintain a substantially continuous tension in the strip between said mechanisms during its advancement, and means effective to preserve said tension irrespective of the operation of said case shifting means.

2. A strip feeding and display device including a telegraph printer for recording a message on a. recording strip and having a platen for automatically and positively feeding said strip in steps into an area of exposure and including guiding means for guiding said strip from the platen to form the said area of exposure substantially tangent to said platen and containing the portion of the recorded message to be displayed, and guiding means including a roller in frictional engagement with said strip and connected by yielding driving means to the power shaft of the printing apparatus for pulling said strip forward for each step of said platen whereby said paper is kept taut in said area during line feed operation.

3. A strip feeding and display device including a telegraph printer for recording a message on a recording strip and having a platen for automatically and positively feeding said strip in steps into an area of exposure and including guiding means for guiding said strip from the platen to form the said area, of exposure substantially tangent to said platen, guiding means including a roller in frictional engagement with said strip and connected by yielding driving means to the main power shaft of said telegraph printer for pulling said strip forward for each step of said platen whereby said paper is kept taut in said area during line feed operation, and take-up means for said strip also connected by yielding driving means to said motor shaft cooperative with said yielding driving means for constantly maintaining the strip in a taut condition. 4. A telegraph printer including a strip feeding and display device, a platen, a backing plate for providing an area of exposure of the printed record for projection purposes, platen feed mechanism to advance intermittently a record strip into said area, guiding means Including a, roller in frictional engagement with said strip and connected by yielding driving means to the main power shaft of the printer for pulling said strip forward for each step of said platen whereby said paper is kept taut in said area during line feed operation, and parallel motion means associated with said platen and said backing plate for maintaining said backing plate substantially in the same plane during the case shifting operations to preserve the focus of the area to be projected.

5. A telegraph printer including a strip feeding and display device, a platen, a backing plate for providing an area of exposure of the printed record for projection purposes, platen feed mechanism to advance intermittently a record strip into said area, guiding means including a roller in frictional engagement with said strip and connected by yielding driving means to the main power shaft of the printer for pulling said strip forward for each step of said platen whereby said paper is kept taut in said area during line feed operation, and means associated with said platen and said backing plate and controlled by said platen for maintaining said backing plate substantially in the same plane during the case shifting operations to preserve the focus of the area to be projected.

6. A telegraph printer including a strip feeding and display device, a platen, a, backing plate for providing an area of exposure of the printed record for projection purposes, platen feed mechanism to advance intermittently a record strip into said area, guiding means including a roller in frictional engagement with said strip and con- 0 nected by yielding. driving means to the main power shaft of the printer for pulling said strip forward for each step of said platen whereby said paper is kept taut in said area during line feed operation, means associated with said platen and said backing plate and controlled by said platen for maintaining said backing plate substantially in the same plane during the case shifting operations to preserve the focus of the area to be projected, and take-up means for said strip also connected by yielding driving means to said power shaft- cooperative with said guiding means and said last recited means for constantly maintaining said strip in a taut condition. 7. A telegraph printer including a strip feeding and display device, a platen, a backing plate for providing an area of exposure of the printed record for projection purposes, platen feed mecha.B nism to advance.intermittently a record strip into said area, guiding means including a roller in frictional engagement with said strip and connected by yielding driving means to the main power shaft of the printer for pulling said strip forward for each step of said platen whereby said paper is kept taut in said area during line feed operation, parallel motion means associated with said platen and said backing plate for maintaining said backing plate substantially in the same plane during the case shifting operations to preserve the focus of the area to be projected, and take-up means for said strip also connected by yielding driving means to said power shaft cooperative with said guiding means and said parallel motion means for constantly maintaining said strip in a taut condition.

8. In a strip feeding and display device, a platen, case shifting means therefor, line feed mechanism associated with said platen to advance intermittently a, strip for display of a substantial area of its surface, a second feed mechanism spaced apart from said line feed mechanism, a re-wind mechanism, a single power shaft for supplying power to all of said mechanisms, yieldable means for transmitting energy from said shaft and for driving said second and third recited mechanisms to maintain a substantially continuous tension in the strip between said mechanisms during its advancement, and parallel motion means associated with said platen and effective to preserve said tension irrespective of the operation of said case shifting means.

CHARLES W. BURCKY.