US3004725A

US3004725A - Double bar jordan plug

Info

Publication number: US3004725A
Application number: US838900A
Authority: US
Inventors: Bruno E Prevost
Original assignee: John W Bolton and Sons Inc
Current assignee: John W Bolton and Sons Inc
Priority date: 1959-09-09
Filing date: 1959-09-09
Publication date: 1961-10-17
Anticipated expiration: 1978-10-17

Description

B. E. PREVOST 3,004,725

DOUBLE BAR JORDAN PLUG Filed Sept. 9, 1959 I, 22 o J I INVENTOR.

BRUNO E. PRE'VOS'T BY 'PM *7 m ATTORNEYS 3,004,725 DOUBLE BAR JORDAN PLUG Bruno E. Provost, West Boxford, Mass., assignor to John W. Bolton & Sons, 1110., Lawrence, Mass, at corporation of Massachusetts Filed Sept. 9, 1959, Ser. No. 838,900 6 Claims. (Cl. 241-294) This invention relates to an improved plug for a rotary refiner of the dovetail groove, double bar type.

It has long been customary in the trade to provide an expansible filler between the pair of bars in each groove and to provide an expansible separator between the pairs of bars in adjacent grooves. Usually the bars have been formed of steel rolled to a special shape with enlarged shoulders, ribs and the like for anchoring the parts as in U.S. Patent 341,223 to Clawson of May 4, 1886, or US. Patent 2,862,424 to Jones of December 2, 1958. It has also been proposed to use bars of rectangular cross section and uniform thickness, there being spaced shoulders on the lower portion of the bars fitting the undercut wall of the groove or fitting under a ring as in US. Patent 1,362,606 to Dorman of December 21, 1920, US. Patent 243,733 to Smith of July 5, 1881, or US. Patent 349,332 to Anderson of September 21, 1886.

While any and all of the structures of the above specified patents serve to anchor one or more of the parts in the groove, it is the expansible separators between the pairs of bars that usually are locked in place only by friction or by providing a divergent face on the bars. The latter system of anchoring the separators not only requires a relatively expensive rolled bar but also takes up considerable space, especially when the bars are closely packed and at the small end of the truncated conical I plug.

It is the object of this invention to provide a grooved, double bar plug in which the bars are of flat, thin, unmachined metal, available at relatively low cost, but are provided with spaced, elongated shoulders for metal to metal engagement with the undercut wall of the groove, only the flat face of the shoulder being machined into a smooth, fiat face.

Another object of the invention is to provide a grooved, double bar plug in which the bars include spaced, ma-

chined shoulders for anchoring the bars in the grooves and also include spaced protuberances therealong for anchoring keystone shaped separators between the pairs of bars.

A further object of the invention is to provide a grooved, double bar plug with expansible keystone shaped separators between the pairs of bars, the separators having grooves in the side walls thereof slidable on rows of protuberances on the bars whereby they cannot be dislodged radially by centrifugal force even before swelling in the paper stock.

Still another object of the invention is to provide a novel low cost Jordan plug of the grooved type wherein ordinary bar metal is used for the knives and anchoring is achieved by low cost punching operations upsetting the metal of the bar into a lower row of shoulders and an upper row of protuberances.

Other objects and advantages of the invention will be apparent fromthe claims, the description of the drawing and from the drawing in which a specific embodiment is illustrated.

FIG. 1 is a perspective view of a refiner plug constructed in accordance with the invention,

FIG. 2 is an enlarged, exploded, fragmentary View, in perspective of the bars, fillers and separators of the invention, and

FIG. 3 is an enlarged, fragmentary, end view of the plug shown in FIG. 1.

United States Patent i. 3,004,725 Cfi Patented Oct. 17, 1961 In the drawing 20 is a Jordan plug of the usual frusto conical shape and comprising a plug body 21 having a plurality of longitudinally extending grooves such as 22, 23 and 24 each of undercut or dovetail cross section. Plug 20 also includes the large end 25, the small end 26 and the shaft 27. The

alternate grooves

22 and 24 extend the full length of the plug body 21 while the alternate grooves such as 23 extend only part way along the plug body because of space limitations at the small end 26. End rings such as 28 are detachahly mounted at each end of plug body 21 for securing the bars against longitudinal movement and the surface of the plug body is designated 29.

It will be understood that the showing of FIG. 1 is not to scale and that actually the grooves are quite close together with the bars relatively closely packed. The enlarged showing of FIGS. 2 and 3 is a more accurate rep resentation of the relative dimensions of the plug bars and grooves. FIG. 3 represents the spacing at the large end of the plug, the

grooves

22, 23 and 24 converging toward each other whereby, at the small end, the

full length grooves

22 and 24 are closely juxtaposed.

As best shown in FIG. 2 the pair of

bars

31 and 32 are identical and back to back and formed of 'unrolled, unmachined metal of rectangular cross section and uniform thickness. Such bar material is commercially available at low cost and in any desired dimensions. Each bar is provided with a row of longitudinally spaced apart shoulders such as 33 and 34 formed by upsetting the material of the bar by punching in another low 'cost operation. Unlike the curved, or hyperboliform, faces of the above specified Anderson patent or the right angular locking faces of the above specified Dorman and Smith patents, the anchoring face 35 of each

shoulder

33 or 34 is elongated, downwardly inclined, flat and smooth and is the only portion of the bar which is machined by milling. Each anchoring face 35 of each

shoulder

33 or 34 is in metal to metal engagement with a metal

undercut face

36 or 37 of a groove such as 22 and, since it is fiat and smooth, an accurate fit is achieved. The

end Walls

38 or 39 of each shoulder are slightly curved but generally right triangular in outline whereby the shoulder resembles an inclined buttress and broadens the base of the bar where it is seated in the bottom 41 of the groove.

. of. Each

protuberance

44 or 45 is upset from the material of the bar by punching, thereby forming a corresponding row of recesses such as 47 on the inner faces 42 of the bars. Each

protuberance

44 or 45 includes a curved face 48 and a pair of

opposite faces

49 and 50 at right angles to the outer face 46, the cross section of the central portion of the protuberance being rectangular in configuration. As shown, the

protuberances

44 and 45 are each staggered with relation to the

shoulders

33 and 34 and located above the space therebetween.

A relatively thin filler 52 of rectangular cross section and formed of expansible material such as wood is seated in each groove between each pair of

bars

31 and 32. A pair of

bars

31 and 32 with a filler 52 therebetween may be slid endwise into the groove as a unit, with the anchoring faces 35 in engagement with the

undercut spaces

36 and 37 of the groove. When the plug is immersed in liquid such as paper stock, the filler swells sufficiently in a circumferential direction to firmly lock the bars in place against the stress and strain and centrifugal force encountered during refining.

Between each pair of bars an expensible separator 53 tangular cross section in each

opposite side face

57 and 58 thereof. The separators 53 are slid endwise into place with the bottom face 54 thereof seated on the surface 219 of plug body 21 and the

grooves

55 and 56 mounted on the rows of

protuberances

44 and 45 of the

bars

31 and 32 and are thereby anchored against outward movement due to centrifugal force before swelling. Upon swelling of the separators a frictional anchoring effect is achieved and any possibility of a separator flying out of the plug assembly is eliminated.

The filler 52, upon expansion by swelling, becomes more firmly secured in place by reason of the portions adjacent the

recesses

43 and 47 swelling into the recesses.

The row of

shoulders

33 and 34 and corresponding recesses 43 upset from the material of the

bars

31 and 32 thus forms means for not only anchoring the bars in the grooves but for also firmly anchoring the fillers 52 between the bars. The row of

protuberances

44 and 45 forms means for anchoring the grooved separators 53 between the pairs of bars and forms an additional means for retaining the fillers 52 by reason of the recesses 47.

I claim:

1. A plug for a rotary refiner comprising a plug body having a plurality of angularly spaced, longitudinally extending grooves of dovetail cross section in the surface thereof; a pair of plug bars seated in each said groove, each bar being of rectangular cross section and having a fiat inner face, a plurality of individual shoulders upset from the material of said bar and spaced longitudinally along the lower, outer side face thereof, each shoulder having a flat, downwardly inclined, smooth anchoring face accurately fitting and engaging the undercut walls of the dovetail groove in which said pair of bars is seated and a plurality of individual protuberances upset from the material of said bar and spaced along the intermediate, outer side face thereof for engagement with corresponding grooves in a separator; a narrow, expansible filler of rectangular cross section seated in each groove between the adjacent flat inner faces of the bars in said groove and a wide, expansible, separator of keystone cross section seated on the surface of said plug body between the intermediate outer side faces of each adjacent pair of bars, each said separator having a continuous groove along each opposite side face thereof for slidably receiving the longitudinally spaced protuberances on the adjacent face of said bars for retaining said separators against outward radial movement.

2. A combination as specified in claim 1 wherein each said filler extends outwardly beyond the protuberances in said bars and each said bar includes recesses in the fiat inner face thereof, at each shoulder and protuberance, into which said expansible filler canswell and expand.

3. In a Jordan plug of the undercut dovetail groove type, the combination of a pair of plug bars arranged at a spaced distance apart in each said groove, said bars being parallel and each of rectangular cross section; a flat inner face on each said bar having a lower, longitudinally extending row, and an intermediate longitudinally extending row, of individual, spaced apart recesses therealong; a flat outer face on each said bar having a lower, longitudinally extending row of individual, spaced apart shoulders therealong, each having a fiat, downwardly inclined, machined face anchored under the adjacent wall of said undercut dovetail groove and an intermediate longitudinally extending row of individual spaced apart protuberancestherealong; a narrow expansible filler of rectangular cross section seated in said groove in engagement with the inner faces of the pair of bars in said groove for locking said bars therein by circumferential expansion, said filler having a plurality of longitudinally spaced portions expanded into said rows of recesses and a wide, expansible separator of keystone cross section between each adjacent pair of bars in said grooves, each said separator having a longitudinally extending continuous groove in each opposite side wall thereof slidably mounted on the row of protuberances of the adjacent bar of each pair forretaining said separator against radial,

' outward movement.

4. A combination as specified in claim 3 wherein each said protuberance includes an upper and a lower flat face at right angles to the adjacent face of said bar and a curved side face.

5. A combination as specified in claim 3 wherein said protuberancesand said shoulders are uniformly staggered along said bars with the protuberances above the spaces between said shoulders.

6. In a Jordan plug of the undercut dovetail groove type the combination of a pair of plug bars arranged at a spaced distance apart in each said groove, said bars being parallel and each of rectangular cross section; a narrow expansible filler of rectangular cross section seated in each said groove between the bars therein, a wide expansible separator of keystone cross section seated on the surface of the plug between each adjacent pair of bars in said grooves, said separators each having continuous grooves in the side faces thereof; first longitudinally spaced means punched in the material of the lower portion of said bars for anchoring the same in said undercut grooves and anchoring said filler therebetween and second longitudinally spaced means punched in the material of the intermediate portion of said bars for anchoring said separators between adjacent pairs of bars.

References Cited in the file of this patent UNITED STATES PATENTS 727,176 Mills May 5, 1903 1,362,606 Dorrnan Dec. 21, 1920 2,709,396 Bridge May 31, 1955