Television deflection yoke mount

A mounting apparatus for use with a television deflection yoke adapted for transverse adjustment on a kinescope comprises an insulator adapted to be fixedly mounted on the neck of the kinescope at the rear of the insulator. The insulator receives horizontal and vertical deflection coils, and a magnetically permeable core, to form a deflection yoke. A plurality of yoke position orientation and fixing means are mounted to the front of the insulator. The position orientation and fixing means each comprise a guide means incorporating a first engagement means. A member, incorporating second engagement means, is slidably disposed within the guide means. The first and second engagement means cooperate to allow the deflection yoke to be securely held in its adjusted position when the sliding member of each orientation and fixing means is in abutment with the kinescope.

This invention relates to mounting apparatus for holding a deflection yoke 
in operating relationship to a television picture tube. 
Color television receivers are increasingly being manufactured with picture 
tubes which produce three horizontally aligned electron beams. Deflection 
yokes for such tubes may then be made which can substantially converge the 
electron beams at all points on the picture tube display screen without 
the need for dynamic convergence circuitry. In order to provide beam 
convergence within acceptable tolerances, the horizontal and vertical 
coils of these self-converging deflection yokes must be precisely located 
and aligned with respect to each other and to the electron beams. 
Imprecise positioning of the yoke coils can result in problems, such as 
asymmetrical deflection fields, which can adversely affect beam 
convergence. 
In order to realize proper yoke positioning in some applications, the yoke 
is adjusted and aligned on the tube during final assembly, either manually 
or automatically by a yoke adjustment machine. When the desired position 
of the yoke is realized, it is important to secure the yoke with respect 
to the kinescope so that movement of the yoke does not occur. One 
technique to accomplish this is through the use of wedges, usually made of 
rubber or plastic, usually inserted manually by an operator at the front 
of the yoke between the yoke and the tube. These wedges are satisfactory 
to prevent movement of the yoke with respect to the tube. However, they 
may be difficult to insert in some receivers, notably those having small 
screen sizes, where the ability to reach the front of the yoke is severely 
limited due to cramped space conditions. 
The use of screw type adjustment means, such as disclosed in U.S. Pat. No. 
4,195,315, alleviates the cramped quarters limitation somewhat, but the 
function of turning a screw complicates the yoke alignment process 
somewhat. Particularly, with the use of automatic yoke adjustment 
apparatus the problem with properly aligning a screw driving tool with the 
adjustment screw can become quite significant, thereby increasing the cost 
and complexity of the yoke adjustment process. 
It is also desirable to manufacture the yoke adjustment or position fixing 
means integral with the yoke. Use of additional adjustment platforms 
mounted to the kinescope or housings mounted to the yoke may increase the 
cost and complexity of the final assembly. Also, the use of such platforms 
or housings may increase the chances that yoke movement subsequent to 
final adjustment may occur due to the increase in the number of parts 
interacting with the yoke. 
In accordance with the present invention, a deflection yoke mounting 
apparatus provides orientation and fixing of the position of a deflection 
yoke on a kinescope. The yoke is adapted for transverse adjustment on the 
kinescope. 
The yoke mounting apparatus comprises an insulator, disposed about the neck 
of the kinescope, which is adapted to be fixedly mounted to the kinescope 
neck at the rear of the insulator. The insulator is dimensioned to receive 
horizontal and vertical deflection coils, and a core to form a deflection 
yoke. 
A plurality of yoke position orientation and fixing means are disposed at 
the front of the insulator and comprise guide means which incorporate a 
flexible first engagement means. A member incorporating second engagement 
means is slidably mounted in the guide means. The first and second 
engagement means cooperate to allow sliding movement of the member toward 
the kinescope but substantially prevent sliding movement of the member 
away from the kinescope. The member is placed in abutment with the 
kinescope to orient and fix the position of the yoke with respect to the 
kinescope.

Referring to FIG. 1, there is shown a deflection yoke insulator portion 20 
of a deflection yoke mount. Insulator portion 20 represents one half of a 
complete insulator, with each half being identical with corresponding 
indexing and locating members. Indexing holes 21 and 22 and indexing pins 
23 and 24 are shown in FIG. 1. Insulator 20 includes channels within front 
and rear portions 25 and 26 of the insulator for receiving the return 
windings of a horizontal deflection saddle coil. Stiffening ribs 27 are 
located along the outside of the insulator flare. A ridge 28 runs the 
length of insulator 20 to separate the horizontal deflection coils. A 
magnetically permeable core (not shown) toroidally-wound with the vertical 
deflection coils fits around the outside of insulator 20. Insulator 20 
also incorporates an opening 30 which permits the insertion of a spacing 
member (not shown) in order to increase the separation between the 
horizontal coils. Tabs 31 are designed to receive a terminal board (not 
shown) in a snap-on fashion for easy electrical connection of the 
deflection coils to the receiver deflection circuitry. 
FIG. 2 illustrates a rear view of the insulator 20. Indexing pins 23 and 24 
can be seen. Insulator stiffening ribs 32 are located along the outside of 
insulator 20 to reduce distortion or bending of the insulator. An 
insulator locking tab 33 snaps into a corresponding slot in a second 
insulator half. 
Around the perimeter of the front 25 of insulator 20 are located ridges 34. 
These ridges occur in pairs when the insulator is completed and form slots 
between the ridges for receiving a yoke positioning apparatus to form a 
deflection yoke mount. The construction and operation of the yoke 
positioning apparatus will be explained later. 
FIG. 3 shows a view of the outer surface of insulator 20. It can be seen 
that ridges 34 extend along the front portion 25 of insulator 20. 
FIG. 4 shows a front view of insulator 20. Coil separation ridge 28, ridges 
34 and locking tab 33 can easily be seen. 
An insulator cap 37 is illustrated in FIGS. 5 and 6. Cap 37 fits over the 
small end 26 of insulator 20. Snap tabs 38 on cap 37 fit over the outer 
edges of end 36 of insulator 20. Cap 37 incorporates fingers 40 which 
encircle the kinescope neck and receive a clamp (not shown) for securing 
the completed yoke to the kinescope. FIG. 6 shows a side cross-sectional 
view of the cap 37. 
FIG. 7 illustrates a color television display system comprising a kinescope 
50 and a deflection yoke 51. The yoke 51 is shown mounted to the kinescope 
50 at the rear of the yoke via clamp 52. The yoke 52 comprises saddle-type 
horizontal deflection coils 54, an insulator 55, and vertical deflection 
coils 56 toroidally-wound on a magnetically permeable core 57. A yoke 
orientation and fixing means 53 is mounted to the yoke insulator 55 and 
contacts the kinescope 50 in such a manner to secure the position of the 
yoke 51 with respect to kinescope 50. In a peferred embodiment, three 
orientation and fixing means 53 are located at 120.degree. intervals 
around the perimeter of the front of insulator 55. The construction and 
operation of the orientation and fixing means will now be described with 
reference to FIGS. 7-11c. 
FIGS. 8a-c illustrate a yoke positioning member 41 which comprises an 
elongated U-shaped channel with a shorter U-shaped member at right angles 
to the elongated member. Only the elongated member is required to be 
U-shaped, but for ease in manufacture a single U-shaped piece may be bent 
to form the structure of member 41. Along the inside surface of the base 
of the U-shaped elongated portion of member 41 is a plurality of ratchet 
teeth 42, seen clearly in the enlarged detail of FIG. 8c. Member 41 fits 
within the U-shaped channel 43 formed in guide member 44 (seen in FIG. 
9b). Guide member 44 is dimensioned to fit between ridges 34 on insulator 
20, for example. Feet-like projections 45 on guide 44 fit over the front 
and rear edge of end 25 of insulator 20 to secure it in place. 
The U-shaped channel 43 in guide 44 is formed by way of flexible ratcheting 
member 46 which extends into the internal cavity of guide 44. Ratcheting 
member 46 interacts with the inclined teeth 42 of member 41 to resist the 
removal of member 41 from guide 44 similar to the operation of all ratchet 
systems. 
In one application, the yoke is fixed to the kinescope neck via clamp 52 
and temporarily held at the front by an automatic yoke adjustment machine. 
The yoke is then adjusted transversely with respect to the kinescope by 
the yoke adjustment machine. It is to be understood that the yoke is 
positioned initially on the kinescope with sufficient space at the front 
of the yoke to allow transverse adjustment by the yoke adjustment machine. 
When the yoke is adjusted to optimize its position on the kinescope, 
members 41 located around the perimeter of the front end of the yoke 
insulator are pushed manually or automatically into their corresponding 
guides 44 until they contact the kinescope. The operation of pushing 
members 41 is much simpler and easily accomplished than turning a screw or 
inserting a wedge. With three positioning apparatus evenly spaced about 
the perimeter of the yoke (at approximately 120.degree. intervals), the 
yoke will be held firmly in position when the three members 41 contact the 
glass of the kinescope. To further secure the yoke, a glue or plastic 
resin may be inserted into the cavity of guides 44 and/or at the points of 
contact of members 41 with the kinescope. FIG. 10 illustrates an 
embodiment of deflection yoke mount in which guides 44 are molded as a 
portion of the insulator, rather than being attached separately. It is to 
be noted that pairs of ridges 34 and molded guides 44 (in FIG. 10) occur 
every 60.degree. rather than every 120.degree. as needed. This permits the 
yoke to be assembled without regard for a particular insulator 
orientation. It is possible therefore, to place positioning members 41 at 
particular angular position with respect to a fixed reference in all 
cases, thereby greatly simplifying yoke assembly. 
FIGS. 11a-c illustrate an alternative embodiment of the deflection yoke 
mount in which the positioning member presents an increased resistance to 
removal from the guide once it has been inserted, with respect to the 
positioning apparatus previously described. This allows the positioning of 
the yoke on the kinescope without additional adhesive. FIG. 11a shows a 
guide in which two flexible ratcheting members 47 and 48 act to form an 
H-shaped channel. The cross-section of the positioning member 50 is also 
H-shaped with ratchet teeth 51 located along the two surfaces which 
interact with ratcheting members 47 and 48. The effect of inserting member 
50 into the guide is to distort the ratcheting members 47 and 48 as shown 
in FIG. 11b such that member 50 will be held in the desired position and 
will thereby hold the yoke permanently in position when the yoke 
adjustment apparatus is removed. 
The previously described embodiment of a deflection yoke mount permits a 
simple, economical means for accurately holding a deflection yoke in 
position after it has been aligned with respect to the kinescope. The 
ratcheting action of the positioning means allows a quick, simple fixing 
of the yoke position which is easily accomplished either manually or with 
an automatic apparatus. The positioning means described provide a 
positive, one-way action which prevents the yoke from becoming dislodged 
from its desired position.