US3885697A

US3885697A - Bean snipper machine

Info

Publication number: US3885697A
Application number: US280494A
Authority: US
Inventors: Joe R Urschel
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-08-14
Filing date: 1972-08-14
Publication date: 1975-05-27
Anticipated expiration: 1992-05-27

Abstract

The invention involves providing and securing together in an end-to-end abutting relationship a plurality of cylindrical sheet metal segments to form an elongated cylinder for accommodating string beans and providing the segments with slots so that when the cylinder is rotated, the ends of the beans will be caused to project outwardly through the slots for severence by knives associated with the cylinder.

Description

United States Patent [191 Urschel [451 May 27, 1975 BEAN SNIPPER MACHINE [76] Inventor: Joe R. Urschel, 202 Michigan,

Valparaiso, Ind. 46383 22 Filed: Aug. 14, 1972 21 Appl. No.: 280,494

[52] U.S. Cl. 220/22; 220/83; 99/639 [51] Int. Cl B65d 85/00 [58] Field of Search 220/22, 4 C, 83, 19, 20,

220/73, 71, 1 B, 5 R, 5 A, 80; 99/635, 637, 639

[56] References Cited UNITED STATES PATENTS 1,298,488 3/1919 Foote 99/639 1,351,143 8/1920 Vaudreuil 99/639 X 1,954,631 4/1934 Langvand .1 220/80 1,966,244 7/1934 Hansen .4 220/5 A 3,102,567 9/1963 Hamilton 99/639 X 3,304,975 2/1967 Urschel 99/639 X 3,318,350 5/1967 Urschel 3,639,809 2/1972 Phlieger, Jr. 220/5 R X Primary ExaminerWilliam 1. Price Assistant ExaminerSteven M. Pollard [57] ABSTRACT The invention involves providing and securing together in an end-to-end' abutting relationship a plurality of cylindrical sheet metal segments to form an elongated cylinder for accommodating string beans and providing the segments with slots so that when the cylinder is rotated, the ends of the beans will be caused to project outwardly through the slots for severence by knives associated with the cylinder.

8 Claims, 13 Drawing Figures PATENTEU M27 1975 3, 8 8 E5 6 97 SHEET 2 BEAN SNIPPER MACHINE The subject invention relates to what is commonly referred to in the art as a string bean snipping machine and more particularly is directed to a machine in which one of the important objects is to utilize strips of sheet material, as distinguished from expensive cast sections, and are formed into cylindrical segments which are secured together in an end-to-end abutting relationship, and the segments are provided with slots so that the string beans traveling through the cylinder will be tumbled therein to cause the ends of the beans to protrude outwardly through the slots for severence by knives, having associated therewith antifriction means, the latter of which bear against the outer peripheral surface of the cylinder.

More explicitly in the above respect, each of the segments is constructed from a strip of sheet material stock having a uniform thickness, a uniform width defined by a pair of longitudinally extending parallel side edges and of a predetermined length defined by trans verse marginal end edges. Each strip is also provided with a series or banks of longitudinally extending wavelike of zigzag slots, a plurality of longitudinally spaced means preferably in the form of notches which intersect said side edges and with a plurality of longitudinally spaced means preferably in the form of openings which are inset from said side and end edges of the strip, all of which will be described more in detail subsequently.

An important feature of the invention is to provide each segment with a maximum or an appreciably greater number of slots than the smaller number provided, for example, in the cast segments or sections disclosed in my US. Pat. No. 3,3l8,350 dated May 9, 1967, and thereby offers a setup whereby a greater volume or quantity of beans may be directed through the cylinder in order to appreciably promote or increase the productive output or capacity of the subject machine.

A specific object of the invention is to provide elongated means preferably in the form of tie-rods which serve to secure the segments in an end-to-end abutting relationship and assist in aligning the segments prior to their assembly and also afford an organization whereby certain partitions are secured in relation to the segments to provide separate units or subassemblies which may be readily assembled and/or disassembled so that, for example, a worn or damaged unit may be readily replaced. The segments are actually short cylinders.

A particular object of the invention is to provide a unique method of assembling the segments and partitions to provide units and a unique method of assembling the units.

A significant objective to the invention is to provide a cylinder with a plurality of partitions, as alluded to above, and in which some, preferably a pair, are permanently secured in a unique manner within the confines of each segment to provide the separate subassemblies or units, above referred to, while other partitions are assembled and jointly supported in a unique way by these units. More particularly, all of the partitions are preferably constructed from sheet material, such as stainless steel, round and planar in shape and each is provided with a relatively large central aperture or opening and with a peripheral edge portion which is interrupted by a plurality of circumferentially spaced means preferably in the form of radial projections which are adapted to project into certain of the openings and notches provided in each segment for locking the said pair of partitions in axially spaced transverse positions within the confines of the segments. The peripheral portion of each partition is also preferably provided with a plurality of circumferentially spaced means preferably in the form of notches through which the elongated means or tie-rods, above referred to, may be extended for securing the units to provide the cylinder. Attention is directed to the fact that the other partitions, above referred to, which are held in place by the units, are preferably made somewhat thicker in cross-section than those locked in the segments. These thicker partitions, as set forth above, are jointly supported by the abutting ends of the segments when the latter are secured together in an end-to-end abutting relationship by the tie-rods.

A further object of the invention is to provide a setup in which the tie-rods also constitute abutment means which serve to lift up the beans and allow them to drop or fall during rotation of the cylinder and thereby promote tumbling of the beans.

Another specific object of the invention is to provide an organization whereby the partitions are disposed in different relative rotative positions in order to promote the flow of the beans through the cylinder and the thicker partitions assist in alignment of the units during assembly.

Another object of the invention is to provide a cylinder in which the internal and external peripheral surfaces of the cylinder wall are smooth and continuous and. free from any projections which would tend to interfere with the flow of the beans through the cylinder or correct positioning of the knives relative to the cylinder. More explicitly in these respects, the size and shapes of the projections on the partitions and the openings and notches in the segments are accurately predetermined in order to facilitate assembly and locate the projections completely within the confines of the openings and notches. Also, the marginal end edges of the strip are welded in a manner to provide a smooth surface at the junction of said ends.

In view of the foregoing, it will be manifest that the invention offers economical advantages with respect to cost of materials, manufacture, assembly, maximum output, overall efficiency and replacement of components.

Additional objectives and advantages of the invention will become apparent after the description hereinafter set forth is considered in conjunction with the drawings annexed hereto.

In the drawings:

FIG. 1 is a perspective view of a bean snipping machine embodying the invention or inventions;

FIG. 2 is a partial side elevational view of the machine showing one of a plurality of knife assemblies having anti-friction means, the latter of which are adapted to bear against the outer peripheral surface of the cylinder of the machine to correctly position the knives for severing or snipping off the ends of the beans;

FIG. 3 is a partial side elevational view of one of the knives of a knife assembly unit disposed in relation to the cylinder;

FIG. 4 is an enlarged partial transverse sectional view depicting one of the knives of a knife assembly provided with the anti-friction or bearing means;

FIG. 5 is a perspective view of one of the units which comprise a segment and partitions therein with portions broken away to illustrate structural details;

FIG. 6 is a partial longitudinal sectional view showing the units assembled and particularly the mode of attaching the partitions thereto;

FIG. 7 is an enlarged partial perspective view showing the mode of securing in place the thicker partitions above referred to;

FIG. 8 is a partial perspective view of one of the strips of sheet material which is utilized to construct each of the segments of the cylinder;

FIG. 9 is a transverse view showing the location of one of the plurality of tie-rods employed to secure the units together;

FIG. 10 is an elevational view showing certain details of the partitions;

FIG. 11 is an enlarged transverse section illustrating additional details with respect to securing the units in a clamped abutting relationship;

FIG. 12 is a modified structure which discloses fasteners for securing the ends of each strip together, as distinguished from welding; and

FIG. 13 is an enlarged transverse section showing the structural details of the fasteners.

The machine disclosed in the subject application is somewhat similar to the one disclosed in my US. Pat. No. 3,318,350 dated May 9, 1967, and, among other things, comprises a rectangular frame generally designated 1, an elongated cylinder generally designated 2 mounted on the frame for rotation, power means, such as a motor 3 operatively connected to the cylinder for rotating the same at a predetermined rate of speed, such as, for example, 40 R.P.M., and a plurality of knife assemblies generally designated 4, which are preferably of the character disclosed and claimed in my U.S. Pat. No. 3,491,817 dated Jan. 27, I970. The cylinder is provided with chambers or pockets, formed in part by partitions, and is mounted in a tilted or inclined position with reference to the horizontal. The beans are adapted to be introduced at its high end or inlet 5 through a chute (not shown) and discharged through an outlet 6 at its lower end and if so desired, onto a conveyor (not shown). When the cylinder is rotated with a mass of beans therein, the beans tumble about and as they climb off the bottom of the cylinder and approach its top, they fall or drop back into one or more of the chambers or pockets and during this act of tumbling the ends of the beans are caused to protrude through slots 7 provided in the wall of the cylinder where they are cut off by the knives of the knife assemblies 4.

Referring more particularly to the structure, above referred to, the rectangular frame 1 may be designed and constructed as desired, but, as depicted in FIG. 1, it is preferably comprised of a pair of short legs 8, a pair of taller legs 9 and an elongated trough 10 supported below the cylinder for receiving the snipped ends of the beans.

The cylinder may be mounted on the frame in any desirable manner. For example, the extremities of the frame may be provided with rollers which respectively engage annular tracks (not shown) which are carried by the extremities of the cylinder. The relationship of the rollers and tracks are such that the cylinder is well supported for rotation.

The structural characteristics of the cylinder will now be described. As depicted in FIG. 1, it is preferably comprised of a pair of cylindrical or annular end segments or sections generally designated 11 and 12 and seven substantially corresponding intermediate segments designated 13,14, l5,l6,17,18, and 19, all nine of which are assembled together in an end-to-end abutting relationship.

The segments 11 through 19 may be designed and constructed in various ways, but as set forth above and as exemplified in FIG. 8, each is preferably constructed from an elongated strip of flexible sheet material, such as stainless steel. More particularly, the segments are of uniform thickness, width, and length in order to promote continuity in manufacturing operations and as sembly techniques and replacement and the width of each segment is defined by a pair of parallel longitudinally extending marginal side edges 20 and the length by a pair of transverse marginal end edges 2i. The side edges 20 are respectively provided with longitudinally spaced means preferably in the form of twenty-seven rectangular notches 22 and each strip intermediate its side edges is provided with a row of longitudinally spaced means preferably in the form of twenty-seven rectangular openings 23 and a row of similar openings 23.

The slots 7, above referred to, are preferably of a zigzag or wavelike character, extend longitudinally, and are preferably arranged in groups or banks which are equally spaced apart both longitudinally and transversely of the strip. For example, each strip, as depicted in FIG. 8, shows a first transverse row of groups of slots generally designated 24, 25, and 26, asecond row of groups generally designated 27, 28, and 29, and a third row of

groups

30, 31, and 32, and so on, with solid portions, such as 33, which separate the groups transversely and with solid portions 34 which separate the groups longitudinally. It should be noted that the rows of means or

openings

23 and 23 are located in the portions 33 on opposite sides of a center row of

groups

25, 28, and 31 of slots and that the means or notches 22 are aligned transversely with the rows of

openings

23 and 23. Otherwise expressed, a transverse row of notches 22 and openings 23 and 23' and the row of

groups

24, 25, and 26 are arranged generally in alignment and the same is true of the others, such as, for example, other notches 22 and

openings

23 and 23 are substantially in alignment with the row of

groups

27, 28, and 29.

As set forth above, one of the important objects of the subject invention is to provide a cylinder comprised of cylindrical segments which are constructed from sheet material, such as stainless steel. The segments or sections are constructed from the strip described above. More particularly, the strips are flexed or formed to provide the nine segments 11 through 19, and each of the latter is preferably provided with a pair of partitions such as 35 and 36 which in combination with the wall of the segment define a centerchamber 37 and open ended chambers 38, as depicted in FIGS. 5 and 6. Partitions 45, which will be described subsequently, provide walls which are common to the chambers 38.

All of the partitions are substantially identical, and each is in the form ofa planar round disc provided with a relatively large center non-circular opening 39, preferably rectilinear or square in shape which has rounded corners 40. Each of the partitions, adjacent its periphery, as alluded to above, is also provided with a plurality of 18 circumferentially spaced means preferably in the form of radial projections 41 and with a plurality of circumferentially spaced means preferably in the form of notches 42 which intersect the periphery. These notches are circumferentially spaced apart and serve to receive nine elongated means preferably in the form of tie-rods 43 which extend longitudinally through all of the partitions and the segments for securing the latter in axial alignment and abutting relation and preferably engage the internal peripheral surfaces of the segments whereby to assist in imparting stability to the cylinder. It should be noted that the number of radial projections 41 is less than the number of each row of the notches 22 and openings 23 and 23' provided in each of the strips or segments and that the projections are arranged in pairs with the notches 42 being located between the pairs. Although there are actually 18 projections on each partition and 27 .notches and 27 openings, the numbers may be less or greater. As illustrated in FIGS. 5 and 6, the projections 41 on the

partitions

35 and 36 are adapted for respective disposition in certain of the openings 23 and 23'.

More explicitly, an important feature of the subject invention is to provide a unique method of assemblying the strips and the pairs of

partitions

35 and 36 therein and this may be readily accomplished, for example, by manipulating a strip and a pair of partitions and flexing the strip, about these partitions so that the projections 41 are caused to enter the openings 23 and 23' desired, whereupon the marginal end edges 21 of the strip are connected, such as by welding as indicated, for example, by the line 44, so that the projections are permanently locked in place and the peripheral edge portions of the portions between the projections and notches will bear against the inner cylindrical surface of the peripheral wall of the segment and thereby assist in shaping, supporting, and stabilizing such wall. The ends of each segment are fused together using inert gas arc welding so that no metal is added during the welding process and, therefore, no grinding action is necessary, all of which serves to reduce the costs of manufacture and assembly.

Attention is directed to the fact that the elongated cylinder is also provided with a plurality of substantially corresponding partitions 45, which are respectively jointly supported by the abutting ends of the adjacent segments. These partitions substantially correspond to the

partitions

35 and 36 which are fixed secured in the segments and are provided with radial projections and notches but are somewhat thicker in crosssection. More specifically in this regard and as depicted in FIGS. 5 and 6, the pairs of

partitions

35 and 36 preferably have a thickness of .050 whereas the thickness of the partitions 45 preferably have a thickness of .062 in order to provide additional support for the abutting ends of the segments. When the thicker partitions are installed, the projections 41 thereon are disposed in certain of the notches 22 which are mated and those portions of the periphery of the partitions between the projections 41 and notches 22 thereof will jointly support and assist in aligning and stabiliziing the abutting ends of the segments.

Also, attention is directed to the fact that the pair of

partitions

35 and 36 carried by each of the segments are not only preferably secured so that they are axially spaced apart in predetermined transverse parallel planes but are disposed in different relative rotative positions which is also true of the thicker partitions 45, the purpose of which is to promote the flow and tumbling of the beans successively through the openings 39 in the partitions but also through the

chambers

37 and 38.

With this unique organization, the square openings 39 are staggered so that the rounded corners 40 of the partitions in each section of the cylinder, as viewed in FIG. 5, are circumferentially spaced apart 40 degrees whereby when the machine is in operation and the cylinder is rotated the beans will be lifted upwardly toward the top of the cylinder by the tie-rods 43 and subsequently fall back into one or more of the chambers and successively travel therethrough the length of the cylinder. The marginal edges of the material defining the openings 39 serve to promote or cause an abrupt interrupting or agitating effect to substantially prevent the beans from bridging across the tops of the openings. The different relative 40 rotative positions of the partitions is achieved through the arrangements of the openings, notches and projections and the fact that the notches 42 in the partitions are preferably circumferentially spaced apart 40. The openings 39 are preferably of such a character or configuration, that different portions defining the same assist in promoting the flow of the beans successively through the chambers. This setup of locating the openings out of registry with one another has proven most efficient in use.

The knife assemblies, generally designated 4, as alluded to above, are disclosed and claimed in my US. Pat. No. 3,491,817 so that only a brief description of these assemblies in the subject application are deemed necessary.

As shown in FIG. 1, there is shown an upper row of nine knife assemblies secured on a horizontal rigid stationary bar 46 anchored to the frame and a lower row of knife assemblies mounted on a bar 47, which is also anchored to the frame in parallel relation to the upper bar. A third bar and knife assemblies, not shown, are

also employed. The assemblies are preferably so arranged that a pair thereof, one from each row, are respectively adapted for disposition in operative relation to the nine units, 11 through 19, of the cylinder, in order to thricely insure that substantially all of the ends of the beans traveling through the cylinder will be snipped or severed.

Each of the assemblies, among other things, as depicted in FIGS. 2 and 3, is comprised of an elongated resiliently flexible arm 48, and one end thereof, is provided with means whereby the assembly may be adjustably and fixedly secured to a bar and its opposite end is provided with a frame 49, which carries three knives 50. Each of the knives is preferably provided with antifriction or bearing means 51, which is preferably constructed of Urethane for engaging the outer peripheral surface of the cylinder so that the bevel cutting edge 52 of each knife as shown in FIG. 4 is disposed a predetermined distance from such surface for accurately severing the ends of the beans. The bearing means 51 serve to appreciably prevent wearing away of portions of the cylindrical surface and particularly maintain the edges of the knives in good condition since there is no metalto-metal contact between the knife edges and the wall of the cylinder.

A modified structure is exemplified in FIGS. 12 and 13 of the drawing whereby the marginal end edges of a sheet metal strip may be connected by utilizing separable fastening means as distinguished from the welding as described above.

More particularly, a plurality of preferably eight fastening means generally designated 53 are employed for connecting the marginal end edges of a strip together Each fastening means shown in FIG. 13 preferably includes a fitting 54 and a pair of socket screws 55 and 56. Each fitting is provided with a pair of parallel threaded apertures 57, which are countersunk as indicated at 58 and each of the socket screws includes a threaded shank 59 for reception in the apertures 57 and a tapered head 60 provided with a socket 611 for receiving a tool for an obvious purpose. It will be noted that the outermost zigzag slots 62 and innermost slots 63 at the ends of the strip, as shown in FIG. 12, are preferably enlarged and countersunk as indicated at 64. The arrangement is preferably such that after the partitions are in place and the strip is flexed about them as set forth above, the

screws

55 and 56 may be readily extended through the enlarged slots and threaded into the fittings 54 and when appreciably tightened, the tapered heads 60 of the screws will exert a camming action against the countersinks 64 to force the marginal end edges of the strip together as shown in FIG. 13. The fittings 54 are preferably provided with curved bearing surfaces which engage the inner periphery of each segment. It will be observed that the screws are circumferentially spaced, that the marginal end portions of the strip are clamped between the screws and fittings and that the outer ends of the screws are preferably inset with respect to the countersinks 64- so that the knives of the knife assemblies and/or bearing means associated therewith will not engage such heads.

The subassemblies or units described above are preferably detachably assembled by utilizing the tie-rods 43 in combination with a pair of end rings 65 and 66 and nuts 67 which are adapted for connection with threaded extremities 68 of the rods. As exemplified in FIG. 11, there is shown the end ring 66 and this end ring is provided with a plurality of nine circumferentially spaced holes 69 through which the rods extend. Each of the end rings is also preferably provided with an inturned axially extending circumferential flange 70 which flanges serve to support the outermost ends of the end segments or units 11 and 12. It will be observed that the outside diameters of the rings and end segments correspond so that the outer peripheries of the rings and the segments are continuous.

The segments may be readily assembled by extending the rods through the holes 69 in the end rings 65 and 66 and through the nine notches 42 provided in the partitions as illustrated, for example, in FIGS. and 6, following which the nuts 67 and suitable lock washers are utilized to draw the ends rings toward one another and thereby clamp the segments in the abutting end-toend relationship as described above. As noted above, the rods serve to hold the units together, assist in supporting and stabilizing the units and provide abutment means which lift the beans upwardly and then allow them to fall into the chambers and thereby impart a tumbling action to the beans so that the ends thereof may extend into the zigzag slots for severence by the knives.

In view of the foregoing, it will be manifest that the attributes of the subject invention include utilizing strips of sheet metal which are formed into circular segments; that partitions also constructed of sheet material are employed; that the tie-rods 43 serve several purposes; that the partitions are secured to the segments in different unique ways, all of which offer distinct ad vantages with respect to appreciable reductions in the cost of materials, labor in manufacturing and assembly of the components, interchangeability of the units to facilitate assembly and replacement, and the use of a much greater number of zigzag slots in a cylinder whereby to appreciably increase the production capacity of the machine as compared to machines presently in commercial use in the trade.

Having thus described my invention, it is obvious that various modifications may be made in the same without departing from the spirit of the invention and, therefore, I do not wish to be understood as limiting myself to the exact forms, constructions, arrangements, and combinations of parts herein shown and described.

I claim:

1. A subassembly comprising: a cylinder having a pcripheral surface provided with circumferentially spaced circumferentially extending zigzag slots and with circumferentially spaced openings, and a round apertured planar partition disposed in said cylinder and provided with circumferentially spaced means disposed in said openings whereby said partition is locked in said cylinder in a plane transverse to its longitudinal axis.

2. in combination: a plurality of cylindrical segments, each of said segments being constructed of sheet material and having a peripheral wall provided with a series of circumferentially spaced zigzag slots, a plurality of elongated means common to and extending longitudinally through said segments for securing the latter in an end-to-end abutting relationship to provide an elongated cylinder for receiving string beans, a plurality of round apertured planar partitions disposed transversely in said cylinder in an axial spaced relationship, cooperating means provided at the ends of said segments, means provided on certain of said partitions which cooperate with said cooperating means for locking said certain partitions in place when said segments are secured in said relationship, said certain partitions also being provided with notches, and said elongated means extend through said notches and engage the peripheral wall of said cylinder for reenforcing said wall.

3. A subassembly for the purpose described comprising a cylinder member constructed from a single strip of metal having a substantially uniform thickness and uniform width and marginal end edges which are secured together so that the strip forms the cylinder member, said cylinder member also being provided with a plurality of circumferentially spaced apart banks of circumferentially extending zigzag slots, a round planar centrally apertured member, and cooperating means provided on said members for locking said planar member in said cylinder when saidend edges are secured, said cooperating means comprising openings provided on one of said members and projections on the others which extend into said openings.

4. The subassembly defined in claim 3, including fit tings and screws which extend through certain of the slots in extremities of said strip into said fittings for clamping said end edges in firm abutting relation and so that said extremities constitute true portions of the cylinder member.

5. In combination: a cylindrical member constructed from sheet material and provided with a plurality of circumferentially extending zigzag slots, a round apertured planar member disposed in said cylindrical memher, and one of said members being provided with a plurality of circumferentially spaced openings and the other with a plurality of circumferentially spaced projections which extend into said openings for locating and securing said planar member in a fixed transverse plane in said cylinder member.

6. In combination: a cylinder provided with a plurality of circumferentially extending zigzag slots and with circumferentially spaced openings spaced from said slots, a round apertured planar partition provided with a plurality of circumferentially spaced projections which respectively extend into said openings for locking said partition in said cylinder whereby the peripheral edge of said partition is disposed in a juxtaposed relation to engage the periphery of said cylinder to assist in stabilizing the latter.

7. In combination: a pair of cylinders, each of said cylinders being provided with a plurality of circumferentially extending zigzag slots, elongated means extending through said cylinders for fixedly securing them in an end-to-end abutting relationship, said abutting ends of said cylinders being provided with mating notches, and a planar apertured partition provided with a plurality of circumferentially spaced projections which extend into said notches for locking said partition in place when said cylinders are so secured.

8. An elongated strip of flexible sheet material provided with a pair of longitudinally extending marginal side edges and with transverse marginal end edges, said strip also being provided with a plurality of groups of zigzag slots, longitudinally spaced openings located between certain of said slots and between said side edges, and at least one of said side edges being provided with longitudinally spaced notches, said openings and said notches serving to respectively receive projections provided on round apertured planar partition members when said strip is flexed about said members and said end edges are secured to provide a cylinder surrounding said members.

Claims

1. A subassembly comprising: a cylinder having a peripheral surface provided with circumferentially spaced circumferentially extending zigzag slots and with circumferentially spaced openings, and a round apertured planar partition disposed in said cylinder and provided with circumferentially spaced means disposed in said openings whereby said partition is locked in said cylinder in a plane transverse to its longitudinal axis.

3. A subassembly for the purpose described comprising a cylinder member constructed from a single strip of metal having a substantially uniform thickness and uniform width and marginal end edges which are secured together so that the strip forms the cylinder member, said cylinder member also being provided with a plurality of circumferentially spaced apart banks of circumferentiallY extending zigzag slots, a round planar centrally apertured member, and cooperating means provided on said members for locking said planar member in said cylinder when said end edges are secured, said cooperating means comprising openings provided on one of said members and projections on the others which extend into said openings.

4. The subassembly defined in claim 3, including fittings and screws which extend through certain of the slots in extremities of said strip into said fittings for clamping said end edges in firm abutting relation and so that said extremities constitute true portions of the cylinder member.

5. In combination: a cylindrical member constructed from sheet material and provided with a plurality of circumferentially extending zigzag slots, a round apertured planar member disposed in said cylindrical member, and one of said members being provided with a plurality of circumferentially spaced openings and the other with a plurality of circumferentially spaced projections which extend into said openings for locating and securing said planar member in a fixed transverse plane in said cylinder member.