|Publication number||US3372733 A|
|Publication date||Mar 12, 1968|
|Filing date||Feb 11, 1964|
|Priority date||Feb 11, 1964|
|Publication number||US 3372733 A, US 3372733A, US-A-3372733, US3372733 A, US3372733A|
|Inventors||Callender Russell J|
|Original Assignee||Russell J. Callender|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (5), Referenced by (22), Classifications (15)|
|External Links: USPTO, USPTO Assignment, Espacenet|
3,372,733 ISTICS 088 March 1968 R. J. CALLENDER METHOD OF MAINTAINING ELECTRICAL CHARACTER OF ELECTRON TUBES AND TRANSIST AND STRUCTURE THEREFOR Filed Feb. 11, 1964 RUSSELL J.
CALLENDER INVENTOR 610; u. og w BY 3 JW United States Patent Ofitice 3,372,733 Patented Mar. 12, 1968 METHOD OF MAINTAINING ELECTRICAL CHAR- ACTERISTICS F ELECTRON TUBES AND TRAN- SISTORS AND STRUCTURE THEREFOR Russell J. Callender, 115 Wildwood Beach Road, Mahtomedi, Minn. 55115 Filed Feb. 11, 1964, Ser. No. 344,019 6 Claims. (Cl. 165--1) This invention relates to a method of increasing the efiiciency and improving the behavior and output characteristics of an electron element selected from the group consisting of electron tubes and transistors, and structure provided therefor. More particularly, the invention relates to an improvement in providing a method of maintaining output efiiciency and electrical characteristics of electron tubes and transistors under conditions of operation in environments of changing from cold to high temperature operation, and the structure provided therefor. Essentially, the invention and improvement primarily concern a method and structure embodied around the glass envelope portion of an electron tubes structure in which the heat radiation of the plate element of the said electron tube is absorbed by the said structure in an exact heat gradient of the said plate element and in which the said structures physical area conducts away and exchanges the accumulated heat to the air flow surrounding the said structure, whereby in an electronic system of the compact type, more adequate dissipation of the internal heat of the plate element of an electron tube is obtained and tube life is prolonged.
The problem of maintaining electron tube output efficiency and electrical characteristics under conditions of prolonged operation in high temperature environment is a measure of the electron tubes accumulated heat factor. The accumulated tube heat impairs the function of the individual elements embodied in the electron tube. This is particularly noticeable in equipment where prolonged operation increases the heat factor of the environment, for example, in such devices as compact equipment in the television and radar art. In television receivers where adequate ventilation maintains the electron tube efiiciency and electrical characteristic, a rated electron tube for such service is adequate, but such an electron tube applied to the compact receivers where environment temperatures are higher are proving inadequate. Attempts have been made to increase the electron tube capacity under such condition but with the larger power input they require, higher costs really defeat the purpose of compact equipment in adding additional heat to the environment of such compact equipments, thus creating the same problem and other problems. This has not been the answer. Further, the efficiency of radar tracking and calculated numerical distances are atfected by changes in tube characteristics due to heat environment.
As indicated, various attempts have been made to overcome this problem as by increasing the tube size and/or making mechanical changes internally of the tube. Such changes and alterations have not satisfactorily provided for uniformity in operation of a hot set. This is especially noticeable in relationship to the vertical dimension of the vertical sweep and the vertical sweep linearity of the picture display on a compact electronic system, as television receiving sets and radar, equipments, as it changes from a normal to hot operation, or over a prolonged period of operation.
Accordingly, it is a particular object of this invention to provide an improvement in the art of using glass electron tubes in compact television receivers and other electron equipments comprising a method of eliminating the overheating of the plate and grid elements within such electron tube and effect thereby compact design. of equiping base,
ment while maintaining efficiency in the electron tube characteristic and output power.
Another object of this improvement in the art of electronic systems is to provide an increase in operational efficiency of electron tubes and of television receiving sets of the compact type by providing a method and structure for maintaining uniform output power in relationship to the vertical dimension of the vertical sweep of the receiving set picture display and the vertical sweep linearity of compact television receiving sets from cold tohot operation through an improvement in maintained control of the electrical characteristics: of electron tubes.
A particular object of this improvement is to provide electron tubes, of the glass envelope and transistor type, with external structure for indirectly controlling the elements within the electronic tube structure and prevent detriment changes in their electrical characteristics and output power as they change from a cold to hot operation.
Another object of this invention is to provide multiavenues of heat absorption and conduction, for dissipation of the plate element heat of electron tubes, by an externalstructure of heat conducting metal plates, as individually spaced fins, about the glass envelope and in close proximity to the plate element of the electron tube so that the radiated heat of said plate element is conducted and absorbed by the said structures individual metal plates or fins.
An additional object of the invention is to maintain radar calibration of the indicator equipments in relation to the distances calibrated or pips indicated after equipments environment heat has advanced in periods of operation.
Further objects and advantages will be apparent from the following description of the accompanying drawings wherein: 7
FIG. 1 is a side plan view of a television receiving chassis portion with an electron tube mounted thereon and illustrates an embodiment of this disclosure;
FIG. 2 is an isometric view of a mounting plate and radiation base support for an electron tube arrangement as shown in FIG. 1;
FIG. 3 is a partial side view of one of a series of fin radiation plates such as illustratively mounted about the electron tube structure of FIG. 1;
FIG. 4 is a modification of the in FIG. 1;
FIG. 5 is illustrative of a single plate fin of the character shown in FIG. 1;
FIG. 6 is a modification of FIG. 1;
FIG. 7 is a top plan view of FIG. 6;
FIG. 8 is an isometric View of one of the modified heat radiation plates illustrated by the structure shown in FIG. 6, and
FIG. 9 is a modified transistor structure illustrating an embodiment of this disclosure.
With reference to FIGURE 1, there is illustrated a fragment of electron tube equipment chassis 10. This chassis is of a compact type in which is illustratively seated a conventional electron tube receiving socket 11. The art is familiar with such chassis and sockets which are adapted to place and position the tube pins of an electron tube 1.2. in suitable electrical contact and wiring apertures 13. There appears to be no necessity of showing the complicated electrical circuits with other tubes and-component elements mounted on the balance of the chassis as is conventional in television receiving sets and equipment chassis of the compact table model and portable type. However, it is to be understood that'the improvement herein provided is applicable to any of the electron tubes in a television receiving set or similar electron tube equipment, as hereinafter described, the spaced fin structure may be mounted on the tube with or without the supportto afford an external tube support and heat radiation structure shown radiating surface about the glass enclosure of an electron tube.
The observable failure, to the public, is usually first apparent at the base of a picture display in television sets. This occurs as a black strip which is primarily caused by a malfunctioning of the vertical output tube through change of its electrical characteristics by or upon overheating in a high temperature environment situation.
It has now been discovered that the electron tubes electrical characteristics can be uniformly maintained when internal tube heat is reduced and controlled by absorption, conduction and radition external of the tube elements and the tube structure per se. For example, there normally appears a hot spot centrally located within an output triode as exemplified in FIG. 1, generally about the location of area A with proportionally reduced temperatures in the relative end areas B.
Accordingly, I have provided a series of thin heat absorbing and conducting metal plate fins 14, of thin sheet steel, copper, aluminum, or the like, in close spaced and preferably in close placed and glass touching relationship, about tube 12. Whereas it is herein provided to standardize on tube size and aperture opening in the metal plate, to make use of friction contact for holding the plate fins in place, it is preferred to provide a self-containing structure which is supported from the base of the tube and also strengthens and supports the tube from being displaced in shipment, or on accidental contact or pressure.
In the tube supporting arrangement there is provided a supporting stand stamped from a metal plate and provided with a platform 16 and a pair of depending legs 17 and 18. Bent at substantially right angles are flanges 19 and 20 which may simply rest on, but are preferably secured to, the chassis by suitable pin or screw means. Seated on, or suitably supported by, the platform 16 are a series of the thin metal heat absorbing and conducting radiative plate fins 14.
While these plate fins 14 may be of any shape as round, square, oblong or of unequal side areas, or configuration, to fit the close proximity of adjacent other electron tubes or components, there is illustrated in FIG. 5 one form of conductor plate fin which is circular. This plate is provided with a center aperture with the inner cut rim slightly indented and bent downwardly as at 23 to provide a narrow inner glass contact surface rim or an absorption heat rim. This contact rim promotes the absorption and conduction of heat from the area within the tube and cooling of the high intense heat of the glass, grid and plate elements within the tube. Adjacent to the outer rim of the plate 14 are apertures 27 and 28. Each of the plate fins 14 is provided with similar coinciding apertures which serve to provide for insertion of bolt or pin reinforcing mounting and spacing means for the plate fins 14. The apertures are preferably larger than the bolt or pin means to permit independent and relative sliding adjustment of each fin about the glass envelope.
For example, as illustrated in FIGURE 1, the heat exchangers and conductor plates 14 are mounted in consecutive closely spaced order with suitable bolt and nut means 29 and 30, holding the said plates in closely spaced relationship by thin washer means 31. The plates 14, as indicated, are adapted to be mounted one by one about the tube, or otherwise the heat exchanber conductor plate assembly may be prefabricated and adapted to slide, relative to aperture and bolt sizes, and be adjusted in heat conducting relationship over the tube. The heat conducting rims 23 of each of the plates 14 are held by washers 31 in slightly spaced adjacent relationship to each other and provide for better glass area contact and absorption of the electron tubes plate element heat radiation during operation. When stacked in metal to metal, or as a solid unit, in close and touching relationship, with the glass, the efliciency of the herein described method and structure is lost.
In the modified structure of FIG. 4, the fin plate elements 14 are of rectangular shape and provided with their opposite corners 14 bent in a plane at right angles to the main surface area of the plate. Suitable larger apertures for the bolt means 29 and 30 are provided in each of the plate elements. The bolt means 29 preferably is of smaller diameter than the apertures permitting a relative independent movement of each plate to frictionally engage and bind the structure about the glass envelope of an electron tube.
While it is apparent that by bending opposed corners of the plates 14 in opposite directions and then stacking one upon another, a spacing arrangement is provided. However, for increasing efficiency in operation, economizing and simplifying in manufacture, it is desired to bend the corners in one direction and mount the plates 14 on a base support 15, which may or may not be secured to the chassis, as described with respect to FIG. 1. While the lower plate 14, of a group of conductor plates, may rest directly upon the base plate of support 15', it is preferred to insert a washer 31 therebetween. As illustrated, the base conductor plate 14' is turned with the bent ends 14 pointing upwardly and resting against the normal undersurface of a conductor plate 14. The next conductor plate is positioned with the bent corners 14 pointing downwardly and resting on the upper surface of the plate 14. Another spacer washer 32 separates the next group of a similar arrangement, all of which are secured together by the one or more bolt means 29' and nut means 30. AS indicated, the bolt means 29' is preferably of smaller diameter than the apertures provided when a pair is used. This permits the plate fins to operate at individual temperature and to be shifted relative to one another for frictional engagement of the inner rim, as at 23, against the glass surface of the tube. If desired, only one bolt means may be used and the plates are then in a relative spaced hinged relationship. While such frictional mounting may be sufficient for holding the plate fins in place about the glass envelope of the tube, it is preferred to also provide a mounting structure which supports the plate fins and also serves to support the tube from displacement. That is, the base support may be left off and the plates or fins independently and relatively shifted to bind the inner rims 23 against the glass envelope or enclosure for the electron tube elements. Thus, the heat conductor structures can be secured in place without the supporting base.
A modified arrangement may otherwise be provided by the structure illustrated in FIGURES 6 and 7. FIG. 6 has the ability of cooling the glass envelope with the accumulated heat at the center of the external structure tending to be conducted toward the ends of the structure thereby making the accumulated heat equally distributed along the glass envelope. This arrangement is less preferred in favor of the FIG. 1 or FIG. 4 presentations. In these arrangements a plurality of individual avenues of metal structure effect the flow of heat away from the electron tube plateelement in an exact distribution of the heat gradient of said electron tube plate element thereby accomplishing no deterioration of output power and electrical characteristic of the electron tube structure of electron tube operation.
In FIGURE 6 the electron tube 35 is mounted by conventional means on chassis 36. About the tube 35 is fitted a heat conductor 37. This conductor 37 is formed of thin vertical metal heat conductor plates 38 having a T or L shape with projecting ends 38 and secured at the top and base by a series of thin plastic rings 39, 40, 41 and 42 of urethan or the like heat resistant resin. The base structure 15" is similar to that described for FIG. l, or otherwise may be eliminated and the rings 3942 frictionally slide over the glass surface of the tube or the one end rests against the base of the tube or on the chassis. This modified structure also serves to reinforce the tube mounting.
As illustrated in FIG. 8, the vertical L-shaped plate radiator structure 38 of FIG. 6, is shown engaged under the top ring 39 which fits about the glass surface of an electron tube. The flange ends of each of the heat conductor plates 38 are preferably in close spaced relationship and broken up in length to have individual heat avenues along the electron tube. This close spacing permits each of the plates to operate independently relative to a particular section of the glass tube surface and effects a discontinuance or disruption of the tendency of the tube to have a concentrated high temperature hot spot area in the tube and on the glass shell or casing. This has been discovered to prolong the tube life, reduce the need for varying power input, with allowance for closer spacing possible and yet maintaining more efiicient and uniform output power and electrical characteristic. In either the vertical or horizontal placement, the plates and support (if used) may be perforated to permit a more rapid air flow through and between the heat conductors; Also, it has been found advantageous to provide the chassis with many perforations to improve air flow and cooling.
The above disclosed method and structure provides for improved dissipation of the gradient heat factor of the plate element of electron tubes as well as the accumulated heat in long periods of operation of equipments. The hottest spot in such tubes is the physical center of the plate element which is gradually cooler toward its plate element physical ends. With the method and structure provided herein, the heat of the plate element of the electron tube is absorbed by the surrounding structure, as described, in exact proportion. Thus, with the air flow surrounding the structure, exchanging the accumulated heat of the internal elements to the air flow, there results in the plate element of an electron tube running or operating at a lower and uniform temperature for long periods of time. Thereby the operation of the grid element and the electron tubes electrical properties are not impaired in any way by the accumulated heat of the electron tubes plate element or change of environment temperature for long periods of operation. The reason for the preferred structure having individual plates not connected together at the glass envelope of electron tube and of transistor structure is to conduct the heat away from the hot spot at the physical center of the electron tubes plate element or transistor structure and conduct the accumulated heat away from the center and end parts of said plate element or transistor base in an exact proportion, thus allowing no accumulated heat to stand on the glass envelope of said electron tube or transistor. Thereby the electron tube attains complete freedom of electrical properties of its grid element in any enviroment situation of operation for the electron tube. This now permits of smaller and uniform tube size without the requirement of increasing tube capacity, as has been practiced in the art.
In this connection, the affect of environment temperature change upon calibration of numerical distances on a radar screen where the original calibration becomes erroneous because of electron tube change of electrical characteristics due to varied environment heat of equipments against the time of operation of such radar equipments, has made this invention particularly useable.
In addition, when the tube element 12 or comprises a transistor, for example, of a silicon-germanium type, or diode, it can likewise be fitted with a series of stacked heat fins as described with reference to FIGURES 1 through 7, over the outside surface area of the transistor. In making this change, the heat sink can be eliminated. Such transistors have heat problems and the output is affected by the temperature. A heat sink is used at present to dissipate the transistor heat. By replacing the heat sink with a spaced spiral metal sheet or series of stacked pipe-like circular fins of different diameters at right angles to the normal of the transistor, and with T type feet in direct contact the difference in the heat area of the transistor can be dissipated proportionally. Thus, the relative ratio of heat gradient is cooled. In this situation the fins the added structure are preferably of pipe-like circular shape with small feet at edge of pipe for area contact and assembled to fit concentrically against the base of said structure of a spiral spring design to fit against the base of transistor. This maintains the mutual electrical frequency cut-off and electrical characteristics of the transistor by manner of heat control.
The pipe-like concentric circular tubes or spiral spring structure are of different diameter to fit one in the other and the transistor base is contacted by the coinciding ends of the stacked different diameter pipe-like tubes and the pipe-like tubes are preferably perforated (not shown) for air flow cooling. For example, a comparable structure is illustrated in FIGURE 9, and comprises a conventional type transistor and heat conductor structure 43. Extending from the heat conductor 47 are conventional transistor leads 44, 45 and 46. The conductor 47 is illustrative shown as a spiral wound heat conductor metal sheet with air spacing between the convolutions: of the coil form and having a T-shaped end 47 which is seated against the one wall of the transistor. In prefabricated transistor structure the heat conductor structure 47 is preferably secured by a suitable heat resistant adhesive as urethan or the like, to one or more of the walls of the transistor. In prefabrication, the transistor structure, the one end of the heat conductor, or conductors, are preferably molded into the wall of the transistor to extend therefrom. Thus, the heat sink can be eliminated and yet provide more efficient transistor operation.
In the invention the capacity of the heat dissipation of the internal elements of the electron tube, and particularly the plate element, depends on the non-equilibrium of the accumulate-d heat distribution of the conductor metal structure and the electron tube, where the area of and the volume of air flow therethrough is controlled by the environment.
The heat conducting metal plate of tube structure is designed for a greater heat dissipation capacity than the electron tube heat creating capacity, thus it frees the elec tron tubes electrical and plate elements of the accumulated heat under the condition of cold operation to hot operation of electronic equipments in varied environmental temperatures against the lapse of the time element of its operation.
From the above, it will be apparent that the method and structure herein provided for improving the efficiency in operation and reducing the cost factor of maintaining an electronic system and particularly a television and radar in better working order, and that certain modifications as contemplated herein and within the scope of the appended claims, may be possible.
What I claim is:
1. A method for controlling and maintaining the output power and electrical characteristics of an enclosed group of internal conductor elements operating at different temperature gradients within an enclosed electronic structure as described, consisting of the steps of positioning the independent rims of a plurality of gradient heat conducting fin means in relatively separate close spaced relationship to each other about the enclosure for said enclosed group of said internal elements, thereby separately and independently effecting the absorption, conduction, and radiation of the internally created heat of each of said internal conductor elements by independently conducting the accumulated heat away from each of the said internal elements, and thereby reducing and maintaining the internal heat pattern of said elements while uniformly maintaining the electrical characteristics and power output of said elements.
2. An electronic structure of the character described having an enclosure and encased therein having separate and spaced he'at radiation elements which change electrical characteristics under operational conditions in an arrangement consisting of a said electronic structure having a series of spaced heat absorbing and heat conducting fins individually mounted at their base in independently spaced heat gradient absorbing, conducting and radiation relationship abutting said enclosure and closely adjacent to the said electronic structure and each of said elements, whereby the internal heat created by the component elements of the electronic structure is independently absorbed in proportional relationship and thereby does not change the electrical characteristics of said electronic structure.
3. An electron equipment chassis having an electron element mounted thereon, a series of spaced independently mounted external heat absorbers and conductors about said electron element, said electron element corn prising a glass envelope for 'a plurality of electron tube elements which develop high, intense heat gradients within the electron tube area and on the glass surface, said series of external heat absorbers and conductors comprising heat radiation fins 'h'avin g spaced inner rim ends mounted in closely spaced relationship to each other at their said spaced ends, said spaced inner rim. ends being in substantially engaging relationship with the glass envelope for the electron tube elements, whereby the electron tube elements created heat gradients are dissipated by individual avenues of said spaced fin structure external of the glass envelope.
4. The structure of claim 2 including a base mounting secured to said electron equipment chassis and supporting said spaced =heat radiation fins.
5. In an electronic structural arrangement of a plurality which components in operation create heat and are subject to a proportional rise in environmental temperature within an enclosure therefor and which heat is directly of electronic components of the character described proportional to the time of operation, the structure for uniformly and proportionally dissipating the rise in environmental temperature of said electronic components consisting of a series of independently spaced and individually supported individual plate fin heat radiators surrounding said enclosure in relative insulated abutting relationship to each other at a point adjacent said enclosure of a said electronic component Within said enclosure therefor, said electronic structure being surrounded with a series of said plate fin heat radiators in close abutting relationship thereto and thereby conducting the excess of created heat from said components and maintaining the designed electrical characteristics of said electronic components.
6. The structure of claim 5 wherein each of the said plate fin heat radiators have an independently supported contact rim fitted in close proximity to a said electronic component and extends from said electronic structure to thereby independently conduct the heat therefrom of said plurality of electronic components.
References Cited UNITED STATES PATENTS 2,434,676 1/1948 Spender -182 2,829,271 4/1958 Boucher.
2,879,977 3/1959 Trought 165-80 3,033,537 5/1962 Brown 165-80 3,205,936 9/1965 Katz 165-185 ROBERT A. OLEARY, Primary Examiner.
CHARLES SUKALO, Examiner.
MEYER PERLIN, Assistant Examiner.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2434676 *||Mar 11, 1944||Jan 20, 1948||Scovill Manufacturing Co||Cooling unit|
|US2829271 *||Aug 10, 1953||Apr 1, 1958||Cormack E Boucher||Heat conductive insulating support|
|US2879977 *||Jul 11, 1957||Mar 31, 1959||Trought Associates Inc||Mounting device|
|US3033537 *||Mar 7, 1960||May 8, 1962||Pacific Semiconductors Inc||Transistor cooler|
|US3205936 *||Jun 20, 1963||Sep 14, 1965||Astro Dynamics Inc||Stacked-fin heat sink|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3498118 *||Dec 23, 1966||Mar 3, 1970||Blh Electronics||Self-heating compensation for bonded filament strain gage transducers|
|US3536960 *||Jun 26, 1968||Oct 27, 1970||Electric Regulator Corp||Heat sink module|
|US5654587 *||Oct 24, 1995||Aug 5, 1997||Lsi Logic Corporation||Stackable heatsink structure for semiconductor devices|
|US5773886 *||Apr 12, 1996||Jun 30, 1998||Lsi Logic Corporation||System having stackable heat sink structures|
|US5869778 *||Apr 22, 1997||Feb 9, 1999||Lsi Logic Corporation||Powder metal heat sink for integrated circuit devices|
|US5900670 *||Mar 19, 1997||May 4, 1999||Lsi Logic Corporation||Stackable heatsink structures for semiconductor devices|
|US5960975 *||Mar 19, 1997||Oct 5, 1999||Tetra Laval Holdings & Finance S.A.||Packaging material web for a self-supporting packaging container wall, and packaging containers made from the web|
|US5963795 *||Jun 25, 1996||Oct 5, 1999||Lsi Logic Corporation||Method of assembling a heat sink assembly|
|US6006827 *||Dec 28, 1998||Dec 28, 1999||Hon Hai Precision Ind. Co., Ltd.||Cooling device for computer component|
|US6330908 *||Jun 27, 2000||Dec 18, 2001||Foxconn Precision Components Co., Ltd.||Heat sink|
|US6360816 *||Dec 23, 1999||Mar 26, 2002||Agilent Technologies, Inc.||Cooling apparatus for electronic devices|
|US6491091 *||Nov 15, 2001||Dec 10, 2002||Polo Technology Corp.||Radiating fin assembly for thermal energy engine|
|US6557626||Jan 11, 2000||May 6, 2003||Molex Incorporated||Heat sink retainer and Heat sink assembly using same|
|US6851467 *||Aug 30, 1999||Feb 8, 2005||Molex Incorporated||Heat sink assembly|
|US8020608 *||Aug 31, 2004||Sep 20, 2011||Hewlett-Packard Development Company, L.P.||Heat sink fin with stator blade|
|US8322897||Apr 5, 2010||Dec 4, 2012||Cooper Technologies Company||Lighting assemblies having controlled directional heat transfer|
|US8545064||Nov 2, 2012||Oct 1, 2013||Cooper Technologies Company||Lighting assemblies having controlled directional heat transfer|
|US20040200601 *||Apr 29, 2004||Oct 14, 2004||Bamford William C.||Heat sink assembly|
|US20060042777 *||Aug 31, 2004||Mar 2, 2006||Delano Andrew D||Heat sink fin with stator blade|
|US20100051231 *||Mar 4, 2010||Fu Zhun Precision Industry (Shen Zhen) Co., Ltd.||Heat dissipation apparatus having a heat pipe inserted therein|
|US20100218929 *||Sep 2, 2010||Fujitsu Limited||Heat sink|
|US20120125588 *||Apr 23, 2010||May 24, 2012||Kyung Soon LEE||Heat dissipation plate for projection-type ic package|
|U.S. Classification||165/80.3, 257/E23.84, 165/185, 257/722|
|International Classification||H01J19/00, H05K7/20, H01J19/74, H01L23/40, H01L23/34|
|Cooperative Classification||H01L23/4006, H01L2023/4062, H01L2023/405, H01J19/74|
|European Classification||H01J19/74, H01L23/40B|