Patent Number: 046648798
Section: description

DETAILED DESCRIPTION As illustrated in the perspective view of FIG. 1, the guide tube flow restrictor 1 is comprised of an outer ring 3 and an inner sleeve 5. The outer ring 3 has an axial bore 7 through the length of the ring, which forms an inner surface 9 facing the axial bore 7. The outer ring 3 also preferably has a groove 11 about the outer surface 13. A flange member 15 is provided on the outer ring 3 adjacent the top, the flange member extending inwardly from the inner surface 9. The flange member may be a separate body connected to the outer ring 3 by means of threads 17, or the flange member may be formed as an integral unit with the outer ring 3. A plurality of flexible segments 19, such as leaf springs, are provided about the inner periphery of the flange member 15, which flexible segments extend axially through and outwardly from the bore 7 of the outer ring 3. The flexible segments 19, depending from the flange member 17 are spaced from the inner surface 9 of the outer ring member 3, forming a gap 21 therebetween. Each flexible segment 19 has, at the terminus 23, an outwardly disposed leg portion 25, the leg portion having an inwardly protruding baffle 27. Also, at the terminus 23, each flexible segment 19 has an inwardly disposed deflecting means 29, preferably comprised of an inwardly protruding extension 31, having at least one angular strut 33 thereon extending upwardly to the flexible segment 19. As illustrated, a pair of angular struts 33 may be provided. The angular strut 33 provides an angular surface 35. The outer ring 3 preferably has a downwardly extending shoulder 37 completely about the inner periphery of the bottom surface 39 of the ring 3, and an upwardly extending shoulder 41 completely about the outer periphery of the top surface 43 thereof. Concentrically within the outer ring 3 and flange member 15 with flexible segments 19, there is an axially insertable inner sleeve 5. The inner sleeve 5, in a cylindrical shape, has an outwardly extending flange 45 at the top thereof, and a passage 47 therethrough for insertion of a shaft as hereinafter described. The bottom edge 49 of the inner sleeve 5 has beveled inner and outer edges 51. Locking means, such as spring clips 53, attached to the outer surface 55 of the flange 45 by attachment means 57 depend from the flange. Also provided in the outer surface 55 is a channel 59 for cooperation with a tool, not shown. The guide tube flow restrictor 1 is designed for use with drive shaft mechanisms passing through an upper support plate 61 (FIGS. 3 and 4), having apertures 63, with the bottom of the outer ring 3 resting on the upper surface 65 of the upper support plate 61. A beveled edge 67 is provided on the lower surface 69 of the upper support plate 61 about aperture 63. The position of the guide tube flow restrictor about a drive shaft 71, such as a control rod drive shaft, is shown in FIG. 4. The assembly of the guide tube flow restrictor is illustrated in FIG. 3. The outer ring 3 is seated on the upper surface 65 of the upper support plate 61 about an aperture 63. The bore 7 and aperture 63 are aligned coaxially, with the shoulder 37 on the bottom surface 39 of the ring 3 flush with the upper surface 65 of support plate 61. In this position, the flexible segments 19 are of a length designed to extend through the aperture 63, with the outwardly extending legs 25 proximate the beveled edges 67 on the bottom surface 69 of the support plate 61 about the aperture 63. The inner sleeve 5 is axially inserted into the bore 7 of the outer ring 3, between the flexible segments 19, in the direction of the arrow shown in FIG. 3. Upon substantially full insertion of the inner sleeve 5 into the bore 7, the bottom wall 49 of the sleeve 5 will contact the deflecting means 29, by contact with the angular surface 35 of struts 33, and complete insertion of the sleeve 5 will radially force the bottom of the segments 19 outwardly, as indicated by the arrows in FIG. 4, until the legs 25 engage the beveled surface 67 on the bottom edge 69 of the support plate 61. The guide tube flow restrictor may thus be assembled and positioned on the support plate without the need for tools. The full insertion of the inner sleeve 5 within the outer ring 3 and placement of the guide tube flow restrictor 1 on the upper support plate 61 is illustrated in FIG. 4. In this position, the inner sleeve 5 and outer ring 3 are engaged and frictionally secured on the upper support plate 61. With the legs 25 of the flexible segments 19 contacting beveled edges 67, the guide tube flow restrictor 1 is locked into place. The lower surface of flange 45 of outer ring 3 contacts the shoulder 41 of the inner sleeve 5. In order to protect the outer ring from excessive forces due to flow of liquid upwardly through the aperture 63 of support plate 61, and premature separation of the outer ring 3 and inner sleeve 5, the baffles 27 on the flexible segments will direct such flow away from the bottom surface 49 of the inner sleeve 5. Also, to prevent any possible lifting of the inner sleeve 5 from its securement within outer ring 3, the spring clips 53, attached to the outer surface 55 of the flange 45 by attachment means 57, are positioned within the groove 11 about the outer surface 13 of the outer ring 3. Such securement prevents separation of the inner sleeve 5 and outer ring 3 during movement of the shaft 71. In order to unlock and remove the guide tube flow restrictor 1 from engagement with the upper support plate 61, the assembly procedure is reversed. Spring clips 53 are released from engagement with the groove 11. The inner sleeve 5 is then axially removed from its position within the bore 7 of the outer ring 3, which releases the bias against the flexible members 19, and the outer ring 3 is readily lifted from the support plate. In instances where the inner sleeve 5 and outer ring 3 are not readily separable, such as after possible corrosive buildup, a tool (not shown) may be used to engage the inner sleeve 5 by engagement in the channel 59 in the outer surface 55 of the flange 45 to provide sufficient gripping of the sleeve 5 to permit axial movement of the same relative to the outer ring 3. In order to reduce the possibility of corrosion or buildup of deposits which could lead to problems in disengagement of the inner sleeve 5 from the outer ring 3 or removal from the support plate 61, the downwardly extending shoulder 37 is provided on the lower surface 39 of the outer ring 3, while the upwardly extending shoulder 41 is provided on the upper surface 43 of the outer ring 3. These shoulders separate the major portion of the lower surface 39 of outer ring 3 from engagement with the upper surface 65 of the support plate, and the major portion of the upper surface 43 of the outer ring 3 from engagement with the flange 45 of the inner sleeve 5. Also, the gap 21, between flexible segments 19 and the inner surface 9 on outer ring 3, about the bore 7, provides for only a point contact between the bottom edge 49 of the inner sleeve 5 and the angular surfaces 35 on struts 33 to preclude buildup of deposits or corrosion that might tend to prevent separation of the inner sleeve 5 and outer ring 3. As described, the present guide tube flow restrictor does not require the use of tools for assembly, but is self-locking. The device is readily and economically fabricated. In addition, provision is made to reduce the likelihood of corrosive problems or deposit buildup between the outer ring and inner sleeve of the device so as to render the same more readily removable and replaceable.