US3497843A

US3497843A - Deflection yoke assembly and mounting

Info

Publication number: US3497843A
Application number: US676166A
Authority: US
Inventors: Homah C Collie Jr
Original assignee: Motorola Inc
Current assignee: Motorola Solutions Inc
Priority date: 1967-10-18
Filing date: 1967-10-18
Publication date: 1970-02-24
Anticipated expiration: 1987-02-24

Description

Feb. 24, 1970 H. c. COLLIE, JR

DEFLECTION YOKE ASSEMBLY AND MOUNTING Filed 001:. 18, 1967 FIG4 \ INVENTOR HOMAH C. COLLIE JR ATTORNEYS.

United States Patent O 3 497,843 DEFLECTION YOKE A SSEMBLY AND MOUNTIN G Homah C. Collie, Jr., Arcade, N.Y., assignor t Motorola, Inc., Franklin Park, Ill., a corporation of Illinois Filed Oct. 18, 1967, Ser. No. 676,166 Int. Cl. H01f 7/00 US. Cl. 335-210 8 Claims ABSTRACT OF THE DISCLOSURE The assembly includes a yoke encircling a cathode ray tube and a cover for the yoke with rearwardly extending fingers each having a cammed outer surface. The assembly also includes a ring having a cammed inner surface to mate with the outer surfaces of the fingers and adapted to be rotated to draw the fingers against the neck of the cathode ray tube.

BACKGROUND OF THE INVENTION After mounting a deflection yoke on a cathode ray tube, it is usually necessary to make final adjustments by axially moving the yoke along the tube neck. Once the position is selected, mounting devices located both at the front and at the back of the yoke are tightened to secure the yoke to the cathode ray tube. In present day assemblies, such devices are generally annular strap-type clamps with a screw positioned in apertures in the ends of the clamp. The strap encircles projections on the yoke assembly so that tightening of the screw secures the yoke to the cathode ray tube. However, these screws must be tightened with a tool such as a wrench or a screwdriver and because of the position of the cathode ray tube within its cabinet, it is often difficult and therefore time consuming to mate the tool with the screw. In addition, the strap has a width on the order of inch to make good mechanical connection to the projections which extend about /2 inch or more. In a color television receiver Where additional components such as convergence apparatus and purity magnets must be mounted on the cathode ray tube neck, neck space is at a premium. In the past, in order to accommodate the widths of the strap and projections, the choice has been to increase the neck length and make the cabinet that much deeped or else place the additional components closer to the assembly thereby limiting the amount of available axial room necessary to properly position the deflection yoke.

Summary of the invention It is therefore an object of this invention to provide a device for mounting a deflection yoke on a cathode ray tube which requires no tools for tightening the same.

Another object is to provide a deflection yoke assembly and mounting therefor which requires a minimum axial space on the neck of the cathode ray tube.

In practicing a preferred form of the invention, a deflection yoke assembly includes a set of windings mounted on a support having a central opening for encompassing the neck of a cathode ray tube. The front end of the support is secured to the flared portion of the cathode ray tube. A cover mounted on the rear end of the support has a central opening to encompass the neck of the cathode ray tube. A plurality of rearwardly extending fingers integrally attached to the cover each have cammed outer surface. A clamp member having a corresponding plurality of cammed inner surfaces mates with the outer surfaces of the fingers and is adapted to be rotated with respect to the fingers to tighten the assembly to the neck of the cathode ray tube.

3,497,843- Patented Feb. 24, 1970 Description of the drawings FIG. 1 is a side view of a cathode ray tube with the means for mounting the deflection assembly;

FIG. 2 is an end view on an enlarged scale of the mounting means of FIG. 1;

FIG. 3 is a view taken along the line 3-3 of FIG. 2;

FIG. 4 is a view taken along the line 4-4 of FIG. 2; and

FIG. 5 illustrates another embodiment of the invention.

Detailed description of the preferred embodiments Referring now to FIG. 1, the cathode ray tube 10 has a funnel or flared portion 12, a neck portion 14 and a front panel or viewing screen (not shown). A yoke assembly 18 has a support structure 20 encircling the neck portion 14 and part of the flared portion 12. A set of windings represented by numeral 22 is mounted adjacent the annular front end portion 24 of the support 20 and serves to deflect the electron beams which travel from guns mounted in the neck portion 14 towards the viewing screen. Actually the windings extend rearwardly over most of the inner and outer surfaces of the support 20. An iron core (not shown) conforming to the shape of the support 20 overlies the windings on the outer surface. A mounting ring 25 has a plurality of integral feet 26 which extend at an angle equal to the angle of taper of the flared portion 12 of the tube 10. Two-sided adhesive tape 28 mounted on one side of the feet 26 is used to adhere the feet to the surface of the flared portion 12. The annular front end portion 24 of the support structure 20 fits inside the ring 25 which acts as a jig to select the position of the assembly 18 so it is concentric with the neck portion 14 of the tube. After the final position is selected, a clamp 30 is used to tighten the ring 25 about the portion 24 to draw the yoke assembly 18 tightly against the cathode ray tube 10.

The support 20 also includes a rear end 32 which is generally rectangular in shape and is formed with rearwardly extending sides to form a housing for wires connected to the windings 22. A base portion or cover 34 is also generally rectangular in shape and has dimensions slightly increased over the dimensions of the rear end 32 and is therefore adapted to be snap fitted onto such rear end to protect the connecting wires and the windings 22. Integrally connected to the cover 34 are a plurality of fingers 36 extending axially rearwardly from the cover. A clamp 38 tightens the fingers 36 to the neck portion 14 to secure the deflection yoke assembly 18.

After the television receiver incorporating the cathode ray tube 10 is fully assembled, the

clamps

30 and 38 are loosened and the deflection yoke assembly 18 is axially moved to optimize color purity and the like. After a position is selected, the

clamps

30 and 38 are tightened to lock the assembly 18 in the desired position.

To more fully appreciate the means which secure the deflection yoke assembly to the neck portion 14 of the cathode ray tube 10, reference is made to FIGS. 24. The cover 34 has a flat surface 39 and an annular inclined surface 40 which slopes toward the center and toward the flared portion 12 of the cathode ray tube 10 and terminates in a plurality of fingers 36= integrally joined to the surface 40 and extending axially rearwardly. The inner diameter of the central opening formed by fingers 36 is slightly less than the diameter of the neck portion 14 of the cathode ray tube 10 so as to fit snugly thereon and to compensate for the tolerances which may exist in the diameter of the neck portion. Each of the fingers 36 has a portion 42 adjacent the inclined surface 40 and a portion 44 extending from the portion 42 and away from the inclined surface 40. Each of the portions 42 has a generally annularly shaped outer surface and the outer surface of the portion 44 of each of the fingers has a cammed shape. The fingers 36 have a length so as to extend only slightly beyond the flat surface 39 of the cover 34 and therefore the cover will require a minimum of axial space on the neck portion 14 of the cathode ray tube 10.

The clamp member 38 has a generally annular outside periphery and has a plurality of cammed surfaces 46 on its inside periphery to correspond in number and shape to the cammed surface 44 o nthe fingers 36 of the cover 34. A pair of

tabs

48 and 50 preferably molded into the cover 34 form grooves with the inclined surface (see FIG. 4). The clamp 38 has a pair of

notches

52 and 54 which are respectively aligned with the tabs 48 and S and inserted thereover. When the clamp 38 is rotated, it will be located between the tab 48 and the inclined surface 40 on one side and between the tab 50 and surface 40 on the other side and therefore will be retained by the cover 34. Because the outer surface of the portion 42. of the fingers 36 is annular and because the outer surface of the portion 44 o fthe fingers is cammed, a shoulder or ridge 55 is formed at their junction substantially parallel to the flat surface 39. The ridge '55 provides a seat for the clamp 38. Preferably the fingers 36 are slightly inclined so as to tilt radially outwardly away from the flared portion 12 of the tube 10 when the cover is inserted on the neck portion 14. This forms a slight depression in the portions 44 of the fingers 36 for preventing slippage of the clamp 38 off of the fingers The clamp 38 also has a pair of

tabs

56 and 58 which may be grasped for rotating the clamp 38. Preferably the tabs are bent so as to be parallel to the main body portion of the clamp 38 but in a higher plane, with the main body portion positioned within the inclined surface 40 and with the

tabs

56 and 58 overlying the flat surface 39 of the cover 34. Accordingly, the mounting assembly is a compact unit and requires a minimum of axial space on the neck portion 14 of the cathode ray tube.

After the deflection yoke assembly 18 is axially adjusted to the proper position, and the clamp 30 on the front end of the support 20 is tightened, the clamp 38 is rotated with respect to the fingers 36 so that the cammed surface of the clamp 38 presents an increasing radial force against the cammed surfaces of the fingers 36 to draw the same against the neck portion 14 and secure the deflection yoke assembly 18. It should be noted that such tightening procedure is accomplished very quickly and efficiently without the use of a tool such as a screw or nut driver. In present day sets, in order to tighten the assembly, a screw or the like must be rotated which, first requires time to position the tool on the screw and, second requires additional time to rotate the screw. The use of tools is undesirable for another reason, that is, the metal tool may touch the high voltage terminal on the cathode ray tube which may be on the order of 25 kilovolts and therefore quite dangerous to the serviceman servicing the television receiver.

A further form of the invention is illustrated in FIG. where the clamp 30, the associated screw and the mounting ring are eliminated. This is accomplished by forming a plurality of resilient feet 60 integrally with the front end 24 of the support 20 which feet have a slope slightly less than the slope of the flared portion 12 of the cathode ray tube 10. 'When the deflection yoke assembly 18 is positioned on the neck portion .14 and is forced up against the flared portion 12, the resiliency in the feet 60 force the assembly 18 rearwardly. The clamp 38 may be tightened at the desired position to preclude further axial or radial movement of the assembly 18. This absence of radial movement will be attained as long as the feet or some portion thereof engage the flared portion 12 to provide the rearward bias of the yoke assembly 18.

What has been described, therefore, is an improved mounting assembly for a deflection yoke which requires no tools to tighten the yoke to the cathode ray tube and requires a minimum of axial space on the neck.

What is claimed is:

1. Apparatus for mounting a deflection yoke on the neck portion of a cathode ray tube having an axis, which apparatus includes in combination, a base portion having a central opening adapted to be slipped on the neck portion of the cathode ray tube, said base portion having means for attachment to the deflection yoke, a plurality of axially extending fingers joined to said base portion, each of said fingers having a cammed outer surface, a clamp member having a corresponding plurality of cammed inner surfaces to mate with the outer surface of said fingers, whereby positioning said clamp member on said fingers and rotation of said clamp member with respect to said fingers draws said fingers against the neck portion to prevent movement of the deflection yoke with respect to the cathode ray tube.

2. In a cathode ray tube assembly having a cathode ray tube with a neck portion and a flared portion and an axis parallel to the neck portion, a deflection yoke disposed on the neck portion of the cathode ray tube and having a front end and a rear end, mounting apparatus including in combination, a base portion having a central opening adapted to be slipped on the neck portion of the cathode ray tube and against the rear end of the deflection yoke to exert an axial force towards the flared portion to bias the deflection yoke against the flared portion, a plurality of axially extending fingers joined to said base portion, each of said fingers having a cammed outer surface, a clamp member having a corresponding plurality of cammed inner surfaces mating with the outer surfaces of said fingers, whereby rotation of said clamped member with respect to said fingers draws the fingers against said neck portion to cause said base portion to maintain the bias of the deflection yoke against the flared portion.

3. A deflection yoke assembly adapted to be mounted on a cathode ray tube having a neck portion and a flared portion, which assembly includes in combination; a set of windings, a support for the windings having front and rear ends and a central opening for encompassing the neck portion of the cathode ray tube, means to secure the front end of the support to the flared portion of the cathode ray tube, a cover member mounted on said rear end of said support and having a central-opening to encompass the neck portion of the cathode ray tube, a plurality of rearwardly extending fingers attached to said cover member, each of said fingers having a cammed outer surface, a clamp member having a corresponding plurality of cammed inner surfaces mating with the outer surface of said fingers, whereby rotation of said clamp member with respect to said fingers draws said fingers against the neck portion and prevents movement of the yoke assembly with respect to the cathode ray tube.

4. The deflection yoke assembly set forth in claim 3 wherein said means to secure the front end of the support comprises a plurality of resilient feet attached to said front end for hearing against said flared portion to spring bias said support rearwardly, whereby rotation of said clamp member substantially prevents movement of the assembly with respect to the cathode ray tube.

5. The deflection yoke assembly set forth in claim 3 wherein said clamp member has a pair of tabs for rotating said member.

6. The deflection yoke assembly set forth in claim 3-, wherein said cover member has a pair of tabs molded therein to form a space between said tabs and said cover member, and wherein said clamp member has a pair of notches aligned with said tabs for slipping said clamp member over said tabs and into said space, whereby rotation of said clamp member causes retention of the same by said tabs.

7. The deflection yoke assembly set forth in c aim 3 wherein said cover member has a depressed portion surrounding said fingers, said cover member having an outer portion, said fingers having an axial length to extend slightly beyond the plane of said outer portion, wherein said clamp member has a main body portion which includes the cammed inner surface and tab means for rotating the same and raised above said main body portion, said main body portion being positioned in said depressed portion to provide a compact mounting assembly.

8. The deflection yoke assembly set forth in claim 3 wherein said fingers have a forward outer surface which is annular and a rearward outer surface which is cammed to form a ridge between said surfaces, with said ridge forming a seat for said clamp member.

References Cited UNITED STATES PATENTS GEORGE HARRIS, Primary Examiner US. Cl. X.R.