Tiltable Display Screen Assembly

Abstract

A chassis is secured to the cabinet of television apparatus for manually tilting the primary image screen of the tube about a horizontal first axis disposed slightly behind the screen. Manual torque is applied by a hand wheel exposed through the cabinet and chassis and rockable about a second axis parallel to and behind the first axis. For torque transfer, a pinion rockable about the second axis with said hand wheel is enmeshed with a concave gear rack which is concentric with said first axis and has a radius of curvature larger than said pinion.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a display screen such as a television receiver. Particularly, the invention relates to means for adjusting the angularity or pitch of a viewing screen in a cabinet.

Use of cathode ray tubes in connection with business machines for production of displays on their display screens in response to operator-controlled keyboards heretofore has become commonplace. Time loss resulting from error correction in production of printed machine output has been minimized from such use. However, variation in operator height, or in ambient conditions of tube use can result in glare from the image screen, thereby reducing operator efficiency. To prevent or overcome glare, a display screen could be tilted.

Heretofore, it has been known to tilt display screens, particularly video tubes, through the agency of a plurality of mechanisms. One of these comprises a rockable platform on which a video tube is mounted within a cabinet. Another mechanism includes a yoke-shaped bracket which is driven linearly in response to manual rotation of a knob, the bracket being coupled to a video tube relatively remote from its display screen. Yet another mechanism comprises a driven worm meshed with a gear secured to a shaft which is carried on a hanger fast with the neck of a video tube, the neck being in a position remote from the display screen of the tube.

Each of said heretofore known mechanisms, while efficient for changing tube angularity or pitch, omits the feature or characteristic considered desireable in a business machine, of tube movement in an angular direction which is the same as the angular direction of movement of a manual adjusting member during tube adjustment. This wanting feature would enable rapid tube adjustment as it is adapted to generate tactile and muscle sensations which are readily correlateable with tube movement and therefore would require minimum training or thought for operation. Accordingly, an operator, even when unfamiliar with a tilting mechanism, could efficiently manage the same, at once, if such feature were present.

It is the principal object of the present invention to adjust the pitch or the angularity of a viewing screen of, for example, a television tube within a cabinet, particularly by providing the aforesaid feature or characteristic, absent from heretofore known screen adjusting mechanisms.

SUMMARY OF THE INVENTION

The foregoing, and other objects of the invention which will become apparent from the ensuing description, are attained in a mechanism for tilting a primary image or display screen mounted within a cabinet about a horizontal first axis disposed at or near the screen. The agency therefor comprises first means for manually generating torque about a second axis parallel to the first axis and disposed rearwardly of the screen. Second means are adapted for imposing the torque on the tube for rocking the screen about the first axis, the second means including a gear assembly with a part concentric to the first axis. As a result, adjusting angular movement of the display screen is in the same angular direction as the direction of movement of the manual member through which the torque is generated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the ensuing detailed description, reference is had to the accompanying drawings on which:

FIG. 1 is a view partially in vertical section and partially in side elevation of a tube and tilting mechanism embodying one form of the invention herein, a part of a chassis being broken out for the purpose of illustration;

FIG. 2 is a view in a horizontal plane according to the line 2--2 of FIG. 1, parts being broken out for reducing drawing area;

FIG. 3 is a detailed view of a portion of the invention according to the line 3--3 of FIG. 2; and

FIG. 4 is a detailed view according to the line 4--4 of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Referring now more particularly to FIG. 1, a visual display apparatus generally designated 10 herein comprises a television tube 12 with a primary or image display screen 14 disposed at the forward end portion of the tube. The tube may be of conventional construction with a customary yoke 16 mounted on its rear end portion and a metal collar or ring 18 rigidly secured to the forward end portion of said tube.

A cabinet 20 within which the tube is disposed may be of plastic fabrication. In the exemplary embodiment, the cabinet comprises a rear casing section 22 and a forward casing section 24, said casing sections being frictionally retained together into a unitary structure upon assembly. Primary image screen 14 is shown offset rearwardly from the forward opening 26 of casing section 24, the latter providing a forwardly projecting apron or overhang about the forward end of the tube.

A chassis 28, which may be a metal fabrication, is shown as a U-shaped channel mounted within casing section 22. The chassis has a pair of laterally opposed vertical or side walls 30 and 32 (FIG. 2). A base or connecting web 34 (FIG. 1) which may be integrally fashioned with said side walls is rigidly connected by any suitable means to the floor 36 of casing section 22 for immobilizing the chassis relative to and within cabinet 20.

Tube 12 is suspended from chassis 28 by the shoulders 37 and 39 (FIG. 2) of a pair of opposed horizontally aligned shoulder screws 38 and 40. The shoulders are coaxial and extend through opposed side walls 30 and 32. Coaxially extending opposed inner end portions 42 (only one of which is shown in FIG. 1) of said shoulder screws are threadedly anchored in a pair of opposed mounting ears or plates 44 and 46. The latter are parallel and rigidly secured in horizontal alignment to opposite sides of the metal ring 18. Thereby, a first or horizontal axis 47, defined by shoulders 37 and 39, is generated adjacent, though disposed slightly behind and transversely of, primary image screen 14 about which the angularity or pitch of the tube can be adjusted. To that end, the screws have a fit within walls 30 and 32 such that the tube may be maintained frictionally at any selected angular aspect. However, the force of engagement is of a magnitude which can be overcome manually in a manner ensuingly to unfold and for enabling rocking of the tube about said axis. Herein, sufficient clearance is provided between the base web 34 of chassis 28 and tube 12 to enable the tube to be angularly rocked vertically about axis 47 within a range of 20.degree., as shown in FIG. 1.

A hand or thumb wheel 48, which is rockable in the directions shown by double headed arrow 49, is rotationally mounted inside chassis 28. A lower segment 50 of the thumb wheel, adapted to be engaged manually for turning the wheel, projects through said chassis and downwardly out of said cabinet through a pair of coextensive slots 52 and 54 in the bottoms of said chassis and cabinet, respectively. The thumb wheel is journalled concentrically about the shoulder 56 (FIG. 4) of a shoulder screw 57; and it thereby comprises means for manually generating torque angularly about a second horizontal axis (defined by shoulder 56) spaced rearwardly from and parallel to axis 47.

Means for imposing the manually generated torque on tube 12 for rocking screen 14 about axis 47 includes a pinion 58. The latter is a part of a gear assembly concentric with shoulder 56 and rigidly secured to an inside face 60 of thumb wheel 48. Accordingly, the pinion and thumb wheel are adapted to move together about the shoulder 56.

The thumb wheel and said pinion are mounted for rotation about an axis fixed relative to the chassis in consequence of the following: A medial portion 61 of screw 57 is threadedly anchored in wall 32 from which shoulder 56 projects horizontally inwardly. A felt washer 62 is disposed about shoulder 56, the washer being frictionally sandwiched inside chassis 28 between the thumb wheel and side wall 32. A flat washer 64 is disposed against the wheel distal face of pinion 58, and a spring washer 66 is compressed by engagement between the flat washer and the head 68 of screw 57 for maintaining a frictional force on the thumb wheel.

A lock nut 70 is mounted on the threaded screw extension 72 from portion 61 outside of the chassis wall 32. A split ring 74, which is disposed about said threaded screw extension, is sandwiched between a flat washer 76 and the lock nut 70 for securing the thumb wheel assembly.

Also included in the torque imposing means is a gear rack or segment 78. The latter comprises another part of the gear assembly and is concentric with and preferably disposed rearwardly from axis 47. This is achieved by generating gear rack 78 as a concavity or with a concave contour whose radius of curvature is centered on axis 47. The gear rack, in the exemplary embodiment, is fashioned on or carried by a bracket 80 which is disposed in a substantially vertical plane. An extension 82 of said bracket is secured to ear 46 by fastening means, such as screws or the like 84. Extension 82 may have a right-angle flange 86 (FIG. 3) engaged along its entire flat forward face with the rear margin 88 of metal ring 18. Flange 86 facilitates assembly of the bracket 80 and tube 12.

In accordance with the present invention, pinion 58 is operably meshed with gear rack 78. The ratio of the radii of curvature of the pinion and said rack determines the mechanical advantage of the tube rocking mechanism herein described. In the illustrated embodiment, the radius of the pinion is about a tenth of the radius of the gear rack; and for each position of the pinion longitudinally of said rack, tube 12 and accordingly screen 14 has a corresponding angular aspect about axis 47. However, the range of tube adjustment is governed by the angular length of the arc defined by said gear rack.

Accordingly, in the exemplary embodiment, because the longitudinal axis 90 of the tube is disposed in a horizontal plane when the condition of the gear assembly is as shown in FIG. 1, upward movement of segment 78 is limited to 5.degree., further movement being blocked by engagement of pinion 58 and the inside edge 92 of bracket 80. At that time, axis 90 will be disposed in the position designated by the reference character 90H. On the other hand, downward movement of gear rack from its horizontal condition is limited to 15.degree., further movement being blocked by the engagement of the inside wall 94 of bracket 80 and the pinion. At that time, axis 90 will be disposed in the position shown by the reference character 90D.

In consequence of the present invention, particularly by reason of the concave gear rack 78 and its concentric association with axis 47, as the thumb wheel 48 moves clockwise, tube 12 and accordingly screen 14 will move clockwise. Correlatively, as said wheel is moved counterclockwise, the tube and accordingly the screen will also move counterclockwise. This feature enhances the ease with which intentional adjustment of the tube in any angular direction of its tilting can be effected, as there is direct correlation between the direction in which the thumb wheel is moved and the direction of response of the screen to such wheel movement. Moreover, the combination of the high ratio between the rack and pinion with the friction of felt washer 62 provide an effective agency for preventing unintentional movement of tube 12 by force applied directly thereto.

As many modifications in the described construction could be conceived, and as many widely different embodiments could be made without departing from the spirit and scope of the claims, it is intended that all matter contained in the accompanying specification shall be considered as illustrative only and not in a limiting sense.

Claims

We claim:

1. In a mechanism for tilting a primary image display screen disposed within a cabinet and about a first axis disposed at or near said screen, the improvement comprised of:

means for manually generating torque;

means for imposing said torque on said screen and rocking said screen about said first axis, said imposing means including a gear assembly with a part concentric to said first axis.

2. A combination according to claim 1 wherein said part comprises a concave gear rack secured to said screen and disposed rearwardly of said screen, and said gear assembly also includes a pinion having a radius of curvature smaller than the radius of curvature of said gear rack, said pinion being meshed with said rack and connected to said generating means concentrically with a second axis parallel to said first axis.

3. A combination according to claim 2 wherein said torque generating means includes a hand wheel connected to said pinion.

4. A combination according to claim 1 and having a second axis parallel to said first axis, said torque generating means and the torque generated thereby disposed about said second axis.

5. A combination according to claim 4 further characterized by a chassis mounted in said cabinet, and wherein said torque generating means includes a member disposed coaxially with said second axis and mounted from said chassis for transferring torque to said part.

6. A combination according to claim 5 wherein said part comprises a gear segment, and said gear assembly also includes a pinion disposed about said member and meshed with said gear segment for movement thereof and said generating means simultaneously and in the same angular direction.

7. A combination according to claim 6 wherein said cabinet has a slot, and said generating means comprises a hand wheel mounted within said cabinet about said second axis in a plane perpendicular to said first axis and exposed to the exterior through said slot.

8. A combination according to claim 7 wherein said hand wheel and said pinion are secured together.