CA1038610A - Method of brazing open meshwork rolls - Google Patents
Method of brazing open meshwork rollsInfo
- Publication number
- CA1038610A CA1038610A CA 230058 CA230058A CA1038610A CA 1038610 A CA1038610 A CA 1038610A CA 230058 CA230058 CA 230058 CA 230058 A CA230058 A CA 230058A CA 1038610 A CA1038610 A CA 1038610A
- Authority
- CA
- Canada
- Prior art keywords
- slots
- roll
- brazing
- strips
- end members
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
Abstract of the Disclosure An improved method for fabricating open meshwork cylindrical rolls of the type wherein the open meshwork cylindrical structure is made of thin corrugated strips of metal. Adjacent strips are bonded together at inter-vals and groups of adjacent strips are swaged together at both ends forming integral, composite end pieces which are then positioned into slots in cir-cular end members of each cylindrical roll. The improved method of fabri-cation includes encircling the swaged and positioned end pieces with a strip of brazing material and then uniformly heating each of the end members, while slowly rotating the roll on its longitudinal axis causing the brazing material to melt and flow freely, by capillary attraction into each slot, thereby brazing the swaged end pieces to the circular end member.
Description
Cylindrical open meshwork rolls are known to the art and have gained wide acceptance in a large number of heavy duty applications where high structural strength is required, while maximizing flow of fluid through the structure. Gne use for such rolls is in making cylindrical suction rolls and other types of filter support media. In one type of open meshwork roll, to which this improvement applies, th~ roll is a unitary hollow cylindrical honeycomb open work formed of alternate straight and undulating thin strips of metal extending axially from one end support to the other. The circular end supports of the rolls haue radial slats to receive and support the ter-minal end pieces of the axial~y extending strips. A more detailed descript-ion of this form of roll construction may be found in my U.S. Patent 3,139,375 showing the bonded end pieces and radial slots, and in my U.S.
Patent 3,590,453 showing the three-part bonded end pieces.
The fabricating procedure used in the prior art to attach the terminal ends of the strips in the slots of the circular end members was to individually and successively braze each strip end piece set into its receiv-ing slot. This procedure was very time consuming in terms of the man hours required to braze each joint separately. In addition, the heating of each `
joint was not uniformly controlled and consequently there was no assurance .
that the brazing of each joint was uniform; indeed because of different tech-niques used by different workmen and the fatiguing nature of the repetitive work, quality of the brazed work varied substantially.
The tolera~ces of the bonded end pieces were not closely controlled -in the prior art. For example, metal strips of 0.050 inches stock, manu~
factured to mill tolerance, could vary by - 0.005 inches in thickness.
Therefore, an end piece of three such strips could vary by 0.030 inches.
The 0.030 inches variation in end piece thickness requires that each joint between the end rolls and end pieces receive a varying amount of brazing material and be heated separately. In addition, in order to be sure that the brazing mater~al did not fl~w out of the joint after brazing, it was -1- ' S
103~6~0 necessary to be sure that the joint had cooled off before the slot was moved from an upright vertical position.
Thus, it was desirable to provide an improved process for obtain-ing high quality and uniform brazed connections between the strips which form the honeycombed open work and the circular end members which support the open work.
According to the present invention there is provided in a method for making open meshwork rolls of the type formed of a pair of circular end members, each having radial slots of uniform dimensions spaced around the inner faces and outer periphery thereof, said slots having openings on the inner faces of said end members and being open to the periphery of the end members, and an open meshwork made rom alternate strips of straight and corrugated thin metal, adjacent strips being bonded together to form integral end pieces fitting into the slots in the end members, the improvement com-prising the steps of: bonding the end pieces by swaging them to closely con-trolled tolerances and inserting them into said slot openings of said slots -~
in said inner faces to form an open meshwork roll with an axis of rotation;
encircling each end member with a strip of brazing alloy, at least partially overlapping said slots the strip being in close proximity to the said slot openings in which the end pieces are inserted; slowly rotating said roll on said axis while applying heat evenly to each end member, thereby melting the strip of brazing alloy and causing it to be free flowing; flowing the free- -~
flowing brazing material into the peripheral openings of said slots in the end members, whereby brazing the end members to the end pieces when the brazing material has solidified.
In this application and the aocompanying drawings, there is shown and described a preferred embodiment of the invention and suggested various alternatives and modifications thereof, but it is to be understood that these are not intended to be exhaustive and that other changes and modifications - . : .
can be made within the scope o~ the invention. These suggestions are se-i , -2-1038610 ~ ~ i lected and included for pu~poses of illustration in order that othersskilled in the art will more fully understand the invention and the principles thereof, and will be able to modify it in a variety of forms, each as may be best suited in the condition of a particular case.
IN THE DRAWINGS
Figure 1 is a cut-away pe~spective view of the roll.
FiguTe 2A is a cross-sectional detailed view of the end members with the brazing strip applied.
Figure 2B is a cross-sectional detailed view of the end members after the brazing material has been melted.
Figure 3 is a detailed view of one arrangement of the end members and strips.
Figure 4 is a detailed view of another arrangement of the end mem-bers and strips. ;
Figure 5 is a cut-away schematic view of the brazing operation.
Figure 1 shows generally a typical construction for an open mesh-work cylindrical roll 12 of the type which could be made by this improved process. Metal strips 14 are shown as being either straight, as at 16, or corrugated, as at 18, and lying axially along the length of roll 12. Adja-cent strips are bonded together at intervals, as at 20, and the ends of sets of adjacent strips are bonded together to form end pieces 22. The end pieces ~-fit into radial slots 24 which are located around the periphery of circular end members ?6 and 27. After roll 12 has been assembled, as shown in Figure 1, a strip of brazing material 36 ~shown in Figure 2A) is applied to the periphery of end members 26 and 27 to encircle the same. Also shown in -Figure 2A are end pieces 22 in radial slots 24.
For further clarity, Figure 3 shows a detailed view of the strips 14, end pieces 22, and slots 24 into which the end pieces 22 fit. In this embodiment, the end pieces 22 are swaged to a tolerance of - .002 inches and the slots 24 are a minimum of .022 inches larger than the largest thick- --3- ~
.. . . . . . . . .. . . . . . .
~038610 ~ ~
ness of the end pieces 22. As a result, for a minimum end piece thickness, the slot will allow at least .004 inches clearance. For maximum strength, the gap 28 to be filled by brazing material should be between .000 inches and .010 inches. It can be seen that the limit achieved by ~his embodiment is within that optimum range. The close clearance maintained between the slots 24 and the swaged end pieces 22 is important for reasons which will be des-cribed hereafter.
Figure 4 is a detailed view similar to Figure 3 except that it shows a slightly different embodiment for an open meshwork structure 30 which -~`
results in additional end-pieces 46 and s,ots 32 in end members 31.
Figure 5 shows the entire roll 12 placed in oven 34. However, any suitable means for uniformly heating the end members 26 and 27 may be used. ~;
A strip of brazing material 36 is shown completely encircling end members ~ ;
26 and 27 at the joints, as at 38, between the end pieces 22 and the end -members 26 and 27. The end members 26 and 27 and strips of brazing material 36 are heated to a temperature at which the brazing material 36 melts and may flow freely. In one embodiment of this process the brazing material ;~-employs a silver or nickel base alloy which flows readily at 1600 to 2200F. `
The heated roll 12 is slowly rotated by motor 40 and drive assembly 42 to ensure that each end member 26 and 27 is heated uniformly. As shown in Figure 2B the free flowing brazing material 44 of strips 36 is drawn by capillary action into the gap 28 between the swaged end pieces 22 and the walls 48 of the slots 24. The gaps 28 between the slots 24 and swaged end ~-pieces 22 must be sufficiently small to maintain capillary attraction between -the slots 24 and the molten brazing material 44 to prevent the material from flowing out of slots 24 regardless of the attitudes of the slots. - -It is also understood that the following claims are intended to cover all of the generic and specific features of the invention herein des-cribed and all statements of the scope of the invention which might be said to f~ll therebetween.
.. ~ . ,.
-4- ;-'
Patent 3,590,453 showing the three-part bonded end pieces.
The fabricating procedure used in the prior art to attach the terminal ends of the strips in the slots of the circular end members was to individually and successively braze each strip end piece set into its receiv-ing slot. This procedure was very time consuming in terms of the man hours required to braze each joint separately. In addition, the heating of each `
joint was not uniformly controlled and consequently there was no assurance .
that the brazing of each joint was uniform; indeed because of different tech-niques used by different workmen and the fatiguing nature of the repetitive work, quality of the brazed work varied substantially.
The tolera~ces of the bonded end pieces were not closely controlled -in the prior art. For example, metal strips of 0.050 inches stock, manu~
factured to mill tolerance, could vary by - 0.005 inches in thickness.
Therefore, an end piece of three such strips could vary by 0.030 inches.
The 0.030 inches variation in end piece thickness requires that each joint between the end rolls and end pieces receive a varying amount of brazing material and be heated separately. In addition, in order to be sure that the brazing mater~al did not fl~w out of the joint after brazing, it was -1- ' S
103~6~0 necessary to be sure that the joint had cooled off before the slot was moved from an upright vertical position.
Thus, it was desirable to provide an improved process for obtain-ing high quality and uniform brazed connections between the strips which form the honeycombed open work and the circular end members which support the open work.
According to the present invention there is provided in a method for making open meshwork rolls of the type formed of a pair of circular end members, each having radial slots of uniform dimensions spaced around the inner faces and outer periphery thereof, said slots having openings on the inner faces of said end members and being open to the periphery of the end members, and an open meshwork made rom alternate strips of straight and corrugated thin metal, adjacent strips being bonded together to form integral end pieces fitting into the slots in the end members, the improvement com-prising the steps of: bonding the end pieces by swaging them to closely con-trolled tolerances and inserting them into said slot openings of said slots -~
in said inner faces to form an open meshwork roll with an axis of rotation;
encircling each end member with a strip of brazing alloy, at least partially overlapping said slots the strip being in close proximity to the said slot openings in which the end pieces are inserted; slowly rotating said roll on said axis while applying heat evenly to each end member, thereby melting the strip of brazing alloy and causing it to be free flowing; flowing the free- -~
flowing brazing material into the peripheral openings of said slots in the end members, whereby brazing the end members to the end pieces when the brazing material has solidified.
In this application and the aocompanying drawings, there is shown and described a preferred embodiment of the invention and suggested various alternatives and modifications thereof, but it is to be understood that these are not intended to be exhaustive and that other changes and modifications - . : .
can be made within the scope o~ the invention. These suggestions are se-i , -2-1038610 ~ ~ i lected and included for pu~poses of illustration in order that othersskilled in the art will more fully understand the invention and the principles thereof, and will be able to modify it in a variety of forms, each as may be best suited in the condition of a particular case.
IN THE DRAWINGS
Figure 1 is a cut-away pe~spective view of the roll.
FiguTe 2A is a cross-sectional detailed view of the end members with the brazing strip applied.
Figure 2B is a cross-sectional detailed view of the end members after the brazing material has been melted.
Figure 3 is a detailed view of one arrangement of the end members and strips.
Figure 4 is a detailed view of another arrangement of the end mem-bers and strips. ;
Figure 5 is a cut-away schematic view of the brazing operation.
Figure 1 shows generally a typical construction for an open mesh-work cylindrical roll 12 of the type which could be made by this improved process. Metal strips 14 are shown as being either straight, as at 16, or corrugated, as at 18, and lying axially along the length of roll 12. Adja-cent strips are bonded together at intervals, as at 20, and the ends of sets of adjacent strips are bonded together to form end pieces 22. The end pieces ~-fit into radial slots 24 which are located around the periphery of circular end members ?6 and 27. After roll 12 has been assembled, as shown in Figure 1, a strip of brazing material 36 ~shown in Figure 2A) is applied to the periphery of end members 26 and 27 to encircle the same. Also shown in -Figure 2A are end pieces 22 in radial slots 24.
For further clarity, Figure 3 shows a detailed view of the strips 14, end pieces 22, and slots 24 into which the end pieces 22 fit. In this embodiment, the end pieces 22 are swaged to a tolerance of - .002 inches and the slots 24 are a minimum of .022 inches larger than the largest thick- --3- ~
.. . . . . . . . .. . . . . . .
~038610 ~ ~
ness of the end pieces 22. As a result, for a minimum end piece thickness, the slot will allow at least .004 inches clearance. For maximum strength, the gap 28 to be filled by brazing material should be between .000 inches and .010 inches. It can be seen that the limit achieved by ~his embodiment is within that optimum range. The close clearance maintained between the slots 24 and the swaged end pieces 22 is important for reasons which will be des-cribed hereafter.
Figure 4 is a detailed view similar to Figure 3 except that it shows a slightly different embodiment for an open meshwork structure 30 which -~`
results in additional end-pieces 46 and s,ots 32 in end members 31.
Figure 5 shows the entire roll 12 placed in oven 34. However, any suitable means for uniformly heating the end members 26 and 27 may be used. ~;
A strip of brazing material 36 is shown completely encircling end members ~ ;
26 and 27 at the joints, as at 38, between the end pieces 22 and the end -members 26 and 27. The end members 26 and 27 and strips of brazing material 36 are heated to a temperature at which the brazing material 36 melts and may flow freely. In one embodiment of this process the brazing material ;~-employs a silver or nickel base alloy which flows readily at 1600 to 2200F. `
The heated roll 12 is slowly rotated by motor 40 and drive assembly 42 to ensure that each end member 26 and 27 is heated uniformly. As shown in Figure 2B the free flowing brazing material 44 of strips 36 is drawn by capillary action into the gap 28 between the swaged end pieces 22 and the walls 48 of the slots 24. The gaps 28 between the slots 24 and swaged end ~-pieces 22 must be sufficiently small to maintain capillary attraction between -the slots 24 and the molten brazing material 44 to prevent the material from flowing out of slots 24 regardless of the attitudes of the slots. - -It is also understood that the following claims are intended to cover all of the generic and specific features of the invention herein des-cribed and all statements of the scope of the invention which might be said to f~ll therebetween.
.. ~ . ,.
-4- ;-'
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a method for making open meshwork rolls of the type formed of a pair of circular end members, each having radial slots of uniform dimens-ions spaced around the inner faces and outer periphery thereof, said slots having openings on the inner faces of said end members and being open to the periphery of the end members, and an open meshwork made from alternate strips of straight and corrugated thin metal, adjacent strips being bonded together to form integral end pieces fitting into the slots in the end members, the improvement comprising the steps of: bonding the end pieces by swaging them to closely controlled tolerances and inserting them into said slot openings of said slots in said inner faces to form a honeycomb roll with an axis of rotation; encircling each end member with a strip of brazing alloy, at least partially overlapping said slots the strip being in close proximity to the said slot openings in which the end pieces are inserted;
slowly rotating said roll on said axis while applying heat evenly to each end member, thereby melting the strip of brazing alloy and causing it to be free flowing; flowing the free-flowing brazing material into the peripheral openings of said slots in the end members, thereby brazing the end members to the end pieces when the brazing material has solidified.
slowly rotating said roll on said axis while applying heat evenly to each end member, thereby melting the strip of brazing alloy and causing it to be free flowing; flowing the free-flowing brazing material into the peripheral openings of said slots in the end members, thereby brazing the end members to the end pieces when the brazing material has solidified.
2. A method as defined in claim 1, wherein: the end members are heated to from 1600° to 2200°F.
3. A method as described in claim 1, wherein: the end members are evenly heated by rotating the roller in an oven.
4. A method as defined in claim 1, wherein: the step of flowing the free-flowing brazing material into the slots comprises forming a narrow gap of predetermined close tolerance between the end pieces and slots to thereby cause the brazing material to flow by capillary attraction.
5. A method for making open meshwork cylindrical rolls which com-prises the steps of: forming a pair of circular roll ends each having radial-ly extending slots of uniform predetermined dimensions spaced around the inner periphery thereof; assembling an open meshwork of straight and corrugated strips of thin metal in a half hexagonal pattern and with one straight end and two corrugated ends of said strips juxtaposed into a single three-piece member all around each opposite side edge of said open work, said strips being bonded to each other; mechanically swaging the said three-piece members into integral composite end units of predetermined dimensions;
then inserting said swaged integral end units into said slots in said end members and establishing clearance gaps therein of predetermined tolerance to form a honeycomb mesh cylinder; then encircling the said end units, while seated in said slots, with a band of brazing alloy extending circumferential-ly around said clearance gaps at each end of said roll; then rotating said roll and applying high temperature to said alloy band while wrapped around said roll ends to cause it to flow freely and fill said clearance gaps bet-ween the inner walls of said slots and the outer faces of said swaged ends by capillary attraction to braze the same uniformly.
then inserting said swaged integral end units into said slots in said end members and establishing clearance gaps therein of predetermined tolerance to form a honeycomb mesh cylinder; then encircling the said end units, while seated in said slots, with a band of brazing alloy extending circumferential-ly around said clearance gaps at each end of said roll; then rotating said roll and applying high temperature to said alloy band while wrapped around said roll ends to cause it to flow freely and fill said clearance gaps bet-ween the inner walls of said slots and the outer faces of said swaged ends by capillary attraction to braze the same uniformly.
6. A method as specified in claim 5, wherein: said step of applying high temperature to said alloy bands encircling each opposite end of said roll includes the step of heating said roll in a box furnace which is uni-formly heated and the step of rotating said roll slowly during said heating step.
7. A method as specified in claim 6, wherein: said box furnace is heated at a temperature of 1600° to 2200°F and wherein the free flowing tem-perature of said brazing alloy is 1600° to 2200°F.
8. The method of attaching a slotted solid end ring to an open mesh-work cylinder which comprises the steps of: mechanically swaging the pro-jecting, terminal, juxtaposed ends of the strips forming said cylinder to a thickness tolerance of ? .002 inches; milling said slots to a uniform pre-determined width .002 inches greater than the largest thickness of said swaged ends to provide each slot with .004 inches clearance; positioning said swaged juxtaposed strip ends each in one of said milled slots to form a cylindrical roll having a central longitudinal axis of rotation, the clearance gaps between each said end and its slot being of predetermined tolerance for capillary action; then wrapping a band of high temperature brazing alloy around each opposite end ring of said roll to cover said clear-ance gaps; then rotating said cylindrical roll on its central longitudinal axis of rotation and simultaneously uniformly heating and melting said alloy into free flowing condition to flow from outside said gaps into said gaps by capillary action to fill the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 230058 CA1038610A (en) | 1975-06-24 | 1975-06-24 | Method of brazing open meshwork rolls |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 230058 CA1038610A (en) | 1975-06-24 | 1975-06-24 | Method of brazing open meshwork rolls |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1038610A true CA1038610A (en) | 1978-09-19 |
Family
ID=4103431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 230058 Expired CA1038610A (en) | 1975-06-24 | 1975-06-24 | Method of brazing open meshwork rolls |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1038610A (en) |
-
1975
- 1975-06-24 CA CA 230058 patent/CA1038610A/en not_active Expired
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