US3313550A

US3313550A - Sanitary stuffing box

Info

Publication number: US3313550A
Application number: US363397A
Authority: US
Inventors: William J Culman
Original assignee: JH Day Co
Current assignee: JH Day Co; LFB USA Inc
Priority date: 1964-04-29
Filing date: 1964-04-29
Publication date: 1967-04-11
Anticipated expiration: 1984-04-11

Description

April 11, 1957 w. J. CULMAN SANITARY STUFFING BOX 4 Sheets-Sheet 1 Filed April 29, 1964 I NVENTOR.

BY W April 1967 w. J. CULMAN 3,313,550

SANITARY STUFFING BOX v Filed April 29, 1964 4 Sheets-Sheet 2 p *1 1 a miww a INVENTOR.

BY M fiumyf m April 11, 1967 w. J. CULMAN 3,313,550

SANITARY STUFFING BOX Filed April 29, 1964 4 Sheets-Sheet 5 [mot/4111111 INVENTOR April 1957 w. J. CULMAN 3,313,550

SANITARY STUFFING BOX Filed April 29, 1964 4 Sheets-Sheet 4 iffd/P/Vi/S' United States Patent O 3,313,550 SANITARY STUFFING BOX William J. Culman, (Zincinnati, Ohio, assignor to The J. H. Day Company, Cincinnati, Ohio, a corporation of Ohio Filed Apr. 29, I964, Ser. No. 363,397 Claims. (Ql. 2774) The present invention relates to mixing apparatus; and is particularly directed to a novel sanitary seal for sealing an opening in the wall of a mixer tank surrounding the agitator shaft.

The present invention is concerned with mixing apparatus, such as ribbon blenders, horizontal mixers and the like, of the type which include a horizontal agitator shaft which extends outwardly through two vertical end walls of the mixer tank. It is conventional in such horizontal mixers to provide stuffing boxes to seal the end tank walls against any leakage along the agitator shaft.

One of the principal difficulties encountered with prior art seals is that both the seals themselves and the areas of the shaft and tank walls adjacent the seals are difficult to clean. In many cases, particularly where a mixer is used in the food or pharmaceutical industries, it is essential that the seal, agitator shaft and mixer tank walls be thoroughly cleaned at frequent intervals, often after each batch.

In the past it has required an excessive amount of time to dissassemble and remove the seals and subsequently to reassemble them. Moreover, with many seals even after they have been disassembled it is still quite diiTicult to get at all parts of the agitator shaft and adjacent tank wall. Other prior art shaft seal constructions have had the disadvantage that they required cumbersome and expensive components for effecting removal of the shaft seal for cleaning purposes.

The principal object of the present invention is to provide a novel sanitary shaft seal which is highly effective to seal around the shaft in normal mixer operation and which ran be removed quickly and easily to permit cleaning of the seal, shaft and mixer wall when desired.

It is another object of the present invention to provide a sanitary seal which can be disassembled to permit cleaning and reassembled without the use of any tools or power elements.

More particularly, the present invention contemplates a sanitary seal comprising a head plate permanently mounted upon the exterior of the tank wall surrounding the agitator shaft opening. This plate carries a plurality of mounting studs and aligning pins which posstion and support a retaining plate and split stuffing box which surround and are spaced from the agitator shaft. A split annular gasket is compressed between the head plate and retaining plate to provide a radial seal. The stuffing box surrounds and embraces a series of split packing rings which provide a seal along the shaft. The outermost surface of these rings is abutted by a split sleeve member which surrounds and engages the shaft and is disposed within the central opening of the split stuffing box. The split sleeve is urged inwardly to compress the packing rings into sealing relationship with the shaft by means of an end plate which receives the agitator shaft and is supported by two bolts carried by the stufiing box. The stuffing box is secured to the head plate and the head plate is in turn secured to the stufliug box by means of hand wheels which rotatably engage the ends of the studs and bolts interconnecting the respective members.

In order to disassemble the stuffing box for cleaning, a worker merely removes the hand wheels retaining the end plate. This end plate is then shifted outwardly along the shaft. Next, the hand Wheels supporting the stutfing box are turned and disengaged. The two halves of the stufiing box and split sleeve member are disengaged from the shaft packing and other elements of the seal. In the ext step, the split packing rings are removed from the shaft and the stuffing box plate, or front retaining plate, is shifted outwardly over the shaft. This exposes the split gasket which is also disengaged from the shaft. After this step, all portions of the agitator shaft both inside and outside of the side Wall are fully exposed for cleaning. Also, the opening in the side wall adjacent to the shaft is exposed permitting the sidewall area to be cleaned thoroughly. The various component elements of the seal which have been removed can also be cleaned prior to assembly.

One exceedingly important advantage of the present seal assembly is that it can be disassembled without the use of tools, cleaned and reassembled in a very short time, for example less than five minutes.

A second important advantage of the present seal is that the packing rings are uncovered from the outer end and are also uncovered about their periphery so that they can be pulled radially free from engagement with the shaft making it unnecessary to slide the rings rearwardly outwardly along the shaft.

A still further advantage of the present sanitary seal is that it is of extremely simple construction and requires a minimum of parts with no power operators.

These and other objects and advantages of the present invention will be more readily apparent from a consideration of the following detailed description of the drawings illustrating a preferred embodiment of the invention.

In the drawings:

FIGURE 1 is a perspective view of a ribbon blender provided with a shaft seal of the present invention.

FIGURE 2 is a perspective View of the present shaft seal in its normal operative position.

FIGURE 3 is a vertical cross sectional view taken through the seal of FIGURE 2.

FIGURE 4 is an exploded perspective view showing the seal in a disassembled condition.

FIGURE 5 is a perspective view of the seal similar to FIGURE 4 showing the seal with the stuffing box and packing removed to permit cleaning of the shaft.

FIGURE 6 is a vertical cross sectional view through the shaft and seal elements shown in FIGURE 5.

One typical machine provided with sanitary stuffing boxes of the present invention is shown in FIGURE 1. The unit there shown is a ribbon blender It although it is to be expressly understood that the present sanitary seal can be used in conjunction with all types of blending and mixing equipment irrespective of the type of agitator provided.

More particularly, the blending or mixing apparatus comprises a tank 11 having vertical end walls 12 and 13. These end walls are provided with suitable openings, such as opening 14 (FIGURE 5), through which extends an agitator shaft 15. Agitator shaft 15 is rotatably supported on two end bearings 16 mounted on support flanges 17 extending outwardly from end Walls 12 and 13. One end of shaft 15 is driven from motor 18 through a suitable drive indicated generally at 24). Since the details of this drive are conventional and constitute no part of the present invention, it is considered unnecessary to describe the drive in detail.

The agitator shaft 15 carries a suitably configurated agitator member, or members. These members may be mounted upon spiders attached to the agitator shaft interiorly of end walls 12 and 13. Again, the specific type of agitator constitutes no part of the present invention. The openings 1% in end Walls 12 and 13 are sealed by means of sanitary seal 21. This seal surrounds agitator shaft 15 exteriorly of each of the end walls 12 and 13 and is disposed intermediate the end wall and bearing 16.

The details of construction of the sanitary seal are best shown in FIGURES 2-4. Since the seals associated with end walls 12 and 13 are identical, only the seal associated with wall 12 will be described. More particularly, the seal assembly comprises an annular tank head plate 22. This head plate surrounds opening 14 and is preferably welded to end wall 12 as indicated at 23 and 24. Head plate 22 is provided with three threaded bores which receive outwardly extending studs 25. It is to be understood that the studs are threaded tightly into the bores so that the studs do not loosen when handles are threaded over them in the manner explained below.

Head plate 22 is also provided with openings for receiving aligning dowel pins 26. These dowel pins are press fit or otherwise permanently mounted within openings in the head plate 22 and extend outwardly from the plate parallel to studs 25 and the axis of shaft 15. When the sanitary seal is in its assembled condition, the outer face of head plate 22 is engaged by an annular gasket member 27. This gasket member, which is made of any suitable material such as white squeegee rubber, is preferably out along one-half of the annulus to form a dovetail joint indicated at 28. Gasket member 27 is of substantially the same size as head plate 22 and is provided with suitable openings 30 for receiving studs 25 and aligning dowel pins 26.

Gasket member 27 is compressed between head plate 22 and stufling box plate 31. Plate 31 is of annular configuration and is of substantially the same outer diameter as gasket member 27 and annular head box plate 22. However, stuffing box plate 31 is provided with a central opening 32 of substantially smaller radius than the central opening through the gasket and head plate 22. As is shown in FIGURES 3 and 4, stufling box plate 31 is also provided with an annular shoulder 33 spaced from opening 32 by an inwardly extending radial retaining flange 34. Plate 31 is further provided with suitable openings 35 for receiving studs 25 and aligning pins 26.

Retaining flange 34 of the plate 31 functions as a forward abutment for a plurality of split Chevron packing rings 36 which surround shaft 15 and engage it in sea]- ing relationship. The rings 36 are preferably molded Teflon rings and are retained by split stufling box members 37 and 38. As is shown in FIGURE 4, in the preferred embodiment the stufling box members are identical and are split along a horizontal diametral line. Each of the stuffing box members comprise a radial flange 49 which is adapted to abut stufiing box plate 31. Each of the flanges 40 is provided with openings 41 for receiving studs 25. Also, each of the flanges 4t) terminates in an annular shoulder 42 adapted for mating engagement with the shoulder 33 formed on plate 31.

Each of the stufiing box sections 37 and 38 also includes an annular or semi-cylindrical section 43. The cylindrical section 43 is provided with a semi-circular inner face 44 adapted to surround and embrace Chevron packing rings 36 and bronze split sleeve members 45 and 46. These split sleeve members embrace shaft 15 and abut the outer face 47 of the end Chevron packing ring.

Stufiing box sections 37 and 38 are held in position by means of handles 48 which threadably engage the ends of studs 25. When tightened down, handles 48 force flanges 40 of the stuffing box sections against plate 31, tightly compressing gasket member 2'7 between plate 31 and head plate 22.

Stufling box members 37 and 38 each include an outer flange portion 50. Each of these flange portions is provided with a vertical slot 51 and lug portions 52 disposed on each side of the slot at the outer end thereof. Lug portions 52 function to retain the heads 53 of bolts 54 against rotation and to releasably retain the bolts within slots 51 in the manner shown in FIGURES 3 and 4. Bolts 54 extend outwardly parallel to the axis of shaft 15. The bolts are also received within vertical slots 55 in end plate 56. This end plate is provided with a central opening 57 surrounding the shaft and an annular shoulder 58 adapted to engage the outer end of split bronze sleeves 45 and 4%. End plate 56 is held in place by means of handles 60 which threadably engage the ends of bolts 54. When handles 66 are tightened, end plate 56 is urged inwardly along shaft 15 toward end wall 12. Consequently, split bearing sleeves 45 and 46 are urged inwardly against Chevron packing rings 36 compressing these rings to provide a tight seal surrounding shaft 15.

The present stuffing box and seal can be disassembled completely to permit cleaning of the mixer without the use of tools. Specifically, to disassemble the unit from its assembled position shown in FIGURES 2 and 3, hand wheels 60 are rotated to loosen them on studs 54. Studs 54 are then shifted rearwardly to disengage heads 53 from lugs 52 and studs 5 are lifted free from slots 51 in flange 50 and slots in end end plate 56. After these studs are removed, end plate 56 is shifted outwardly along shaft 15 to the position shown in FIGURES 5 and 6. Next, the four hand wheels 48 are removed. This permits removal of stufling box sections 37 and 38. Specifically, these stufiing box sections are disengaged from bolts 25 and are pulled outwardly as indicated diagrammatically in FIGURE 4. The split packing rings 36 are then pulled from the shaft and plate 31 is shifted outwardly as indicated in FIGURES 5 and 6. Finally, gasket 27 is removed. This gasket can be completely disengaged from the shaft by separating dovetail joint 28.

With the seal thus completely removed, the various components can readily be cleaned. Also, agitator shaft 15 and the surrounding areas of end wall 12 are fully exposed for quick and thorough cleaning. Following the cleaning operation, the parts are reassembled by reversing the steps described above.

From the foregoing disclosure of the general principles of the present invention and the above description of a preferred embodiment of the invention, those skilled in the art will readily comprehend the various modifications to which the invention is susceptible. Therefore, I desire to be limited only by the scope of the following claims.

Having described my invention, I claim:

1. In a sanitary seal construction for a mixer of the type having a shaft passing outwardly through an opening in an end wall of said mixer, the shaft being rotatably journalled in a bearing spaced from said end wall, the novel combination which comprises an annular head plate mounted upon said mixer wall surrounding said opening, a first annular retaining plate, a split annular gasket interposed between said annular head plate and said retaining plate, a plurality of studs carried by said head plate extending outwardly from said plate parallel to said shaft, said first retaining plate having openings receiving said studs, a split stuffing box having a radial flange in abutment with said retaining plate and having openings for receiving said studs, said split stuffing box having a cylindrical central opening surrounding said shaft and spaced therefrom, a plurality of knob members threadably engaging said studs for releasably securing said split stuffing box, a plurality of packing rings surrounding said shaft and being disposed within the cylindrical central opening in said stuffing box, the innermost of said rings being in abutment with said retaining plate, a split sleeve member surrounding said shaft and being at least partially disposed within the opening in said stufiing box, said split sleeve member being in abutment with said packing rings, and means for forcing said sleeve against said rings, said means comprising an end plate having a central opening receiving said shaft, said end plate being in engagement with the end of said split sleeve member, a plurality of elongated bolts carried by said split stufling box and extending parallel to said agitator shaft, said end plate being configurated to receive said bolts, and knob members threadably engaging the ends of said bolts, said knob members being in abutment with said end plate.

2. In a sanitary seal construction for a mixer of the type having a shaft passing outwardly through an opening in an end wall of said mixer, the shaft being rotatably journalled in a bearing spaced from said end wall, the novel combination which comprises a first annular retaining plate, a plurality of studs, means mounting sai studs fro-m said end wall, said studs extending outwardly from said end wall parallel to said shaft, said first retaining plate having openings receiving said studs, a split stufiing box having a radial flange in abutment with said retaining plate and having openings for receiving said studs, said split stufling box having a cylindrical central opening surrounding said shaft and spaced therefrom, a plurality of knob members threadably engaging said studs for releasably securing said split stuffing box, a plurality of packing rings surrounding said shaft and being disposed within the cylindrical central opening in said stuffing box, the innermost of said rings being in abutment with said retaining plate, a sleeve member surrounding said shaft and being at least partially disposed Within the opening in said stufling box, said sleeve member being in abutment with said packing rings, and means for forcing said sleeve against said rings, said means comprising an end plate having a central opening receiving said shaft, said end plate being in engagement with the end of said sleeve member, a plurality of elongated bolts carried by said split stufiing box and extending parallel to said agitator shaft, said end plate being configurated to receive said bolts, and knob members threadably engaging the ends of said bolts, said knob members being in abutment with said end plate.

3. In a sanitary seal construction for a mixer of the type having a shaft passing outwardly through an opening in an end wall of said mixer, the shaft being rotatably journalled in a bearing spaced from said end wall, the novel combination which comprises an annular head plate mounted upon said mixer wall surrounding said opening, a first annular retaining plate, a split annular gasket interposed between said annular head plate and said retaining plate, a plurality of studs carried by said head plate extending outwardly from said plate parallel to said shaft, said first retaining plate having openings receiving said studs, two stufling box members abutting one another in a horizontal plane, each of said stufling box members having a radial flange in abutment with said retaining plate and having openings for receiving said studs, each of said stuffing box members having a semi-cylindrical concavity surrounding said shaft and spaced therefrom, a plurality of knob members threadably engaging said studs for releasably securing said stufling box members, a plurality of packing rings surounding said shaft and being disposed within the concavities of said stuffing box members, the innermost of said rings being in abutment with said retaining plate, two sleeve members surrounding said shaft and being at least partially disposed Within the opening in said stufiing box, said sleeve members being in abutment with said packing rings, and means for forcing said sleeve members against said rings, said means comprising an end plate having a central opening receiving said shaft, said end plate being in engagement with the end of said sleeve members, a plurality of elongated bolts carried by said stufling box members and extending parallel to said agitator shaft, said end plate being configurated to receive said bolts, and knob members threadably engaging the ends of said bolts, said knob members being in abutment with said end plate.

4. In a sanitary seal construction for a mixer of the type having a shaft passing outwardly through an opening in an end Wall of said mixer, the shaft being rotatably journalled in a bearing spaced from said end wall, the novel combination which comprises an annular head plate mounted upon said mixer wall surrounding said opening, a first annular retaining plate, a split annular gasket interposed between said annular head plate and said retaining plate, a plurality of studs carried by said head plate extending outwardly from said plate parallel to said shaft, said first retaining plate having openings receiving said studs, a split stufiin-g box split along a horizontal axis, said stufiing box having a radial flange in abutment with said retaining plate and having openings for receiving said studs, said split stulfing box having a cylindrical central opening surrounding said shaft and spaced therefrom, a plurality of knob members threadably engaging said studs for releasably securing said split stufling box, a plurality of split packing rings surrounding said shaft and being disposed within the cylindrical central opening in said stufling box, the innermost of said rings being in abutment with said retaining plate, a split sleeve member surrounding said shaft and being at least partialy disposed within the opening in said stuffing box, said split sleeve member being in abutment with said packing rings, and means for forcing said sleeve against said rings, said means comprising an end plate having a central opening receiving said shaft, said end plate being in engagement with the end of said split sleeve member, a plurality of elongated bolts carried by said split stufiing box and extending parallel to said agitator shaft, said end plate being configurated to receive said bolts, and knob members threadably engaging the ends of said bolts, said knob members being in abutment with said end plate.

5. In a sanitary seal construction for a mixer of the type having a shaft passing outwardly through an opening in an end wall of said mixer, the shaft being rotatably journalled in a bearing spaced from said end wall, the novel combination which comprises an annular head plate mounted upon said mixer wall surrounding said opening, a first annular retaining plate, a split annular gasket interposed between said annular head plate and said retaining plate, a plurality of studs carried by said head plate extending outwardly from said plate parallel to said shaft, said first retaining plate having openings receiving said studs, a split stufling box split along a horizontal axis, said stufling box having a radial flange in abutment with said retaining plate and having openings for receiving said studs, said split stufling box having a cylindrical central opening surrounding said shaft and spaced therefrom, a plurality of knob members threadably engaging said studs for releasably securing said split stuffing box, a plurality of split packing rings surrounding said shaft and being disposed within the cylindrical central opening in said stufling box, the innermost of said rings being in abutment with said retaining plate, a split sleeve member surrounding said shaft and being at least partially disposed within the opening in and stuffing box, said split sleeve member being in abutment with said packing rings, and means for forcing said sleeve against said rings, said means comprising an end plate having a central opening receiving said shaft, said end plate being in engagement with the end of said split sleeve member, said stufling box having a second flange remote from said radial flange, said second flange having two vertical slots formed therein and having lugs formed adjacent to the ends of said slots, an elongated bolt carried by said slots, the bolts including heads in engagement with said lugs, said end plate being configurated to receive said bolts, and knob members threadably engaging the ends of said bolts, said knob members being in abutment with said end plate.

References Cited by the Examiner UNITED STATES PATENTS 685,959 11/1901 Ward 277-104 706,976 8/1902 Macindoe 277104 1,034,696 8/1912 Danie-ls et a1 277107 2,137,328 11/1938 Bissell 277-66 XR 2,837,356 6/1958 Beaman 2774 3,076,655 2/1963 Washburn 277-4 SAMUEL ROTHBERG, Primary Examiner.

Claims

1. IN A SANITARY SEAL CONSTRUCTION FOR A MIXER OF THE TYPE HAVING A SHAFT PASSING OUTWARDLY THROUGH AN OPENING IN AN END WALL OF SAID MIXER, THE SHAFT BEING ROTATABLY JOURNALLED IN A BEARING SPACED FROM SAID END WALL, THE NOVEL COMBINATION WHICH COMPRISES AN ANNULAR HEAD PLATE MOUNTED UPON SAID MIXER WALL SURROUNDING SAID OPENING, A FIRST ANNULAR RETAINING PLATE, A SPLIT ANNULAR GASKET INTERPOSED BETWEEN SAID ANNULAR HEAD PLATE AND SAID RETAINING PLATE, A PLURALITY OF STUDS CARRIED BY SAID HEAD PLATE EXTENDING OUTWARDLY FROM SAID PLATE PARALLEL TO SAID SHAFT, SAID FIRST RETAINING PLATE HAVING OPENINGS RECEIVING SAID STUDS, A SPLIT STUFFING BOX HAVING A RADIAL FLANGE IN ABUTMENT WITH SAID RETAINING PLATE AND HAVING OPENINGS FOR RECEIVING SAID STUDS, SAID SPLIT STUFFING BOX HAVING A CYLINDRICAL CENTRAL OPENING SURROUNDING SAID SHAFT AND SPACED THEREFROM, A PLURALITY OF KNOB MEMBERS THREADABLY ENGAGING SAID STUDS FOR RELEASABLY SECURING SAID SPLIT STUFFING BOX, A PLURALITY OF PACKING RINGS SURROUNDING SAID SHAFT AND BEING DISPOSED WITHIN THE CYLINDRICAL CENTRAL OPENING IN SAID STUFFING BOX, THE INNERMOST OF SAID RINGS BEING IN ABUTMENT WITH SAID RETAINING PLATE, A SPLIT SLEEVE MEMBER SURROUNDING SAID SHAFT AND BEING AT LEAST PARTIALLY DISPOSED WITHIN THE OPENING IN SAID SHUFFIMG BOX, SAID SPLIT SLEEVE MEMBER BEING IN ABUTMENT WITH SAID PACKING RINGS, AND MEANS FOR FORCING SAID SLEEVE AGAINST SAID RINGS, SAID MEANS COMPRISING AN END PLATE HAVING A CENTRAL OPENING RECEIVING SAID SHAFT, SAID END PLATE BEING IN ENGAGEMENT WITH THE END OF SAID SPLIT SLEEVE MEMBER, A PLURALITY OF ELONGATED BOLTS CARRIED BY SAID SPLIT STUFFING BOX AND EXTENDING PARALLEL TO SAID AGITATOR SHAFT, SAID END PLATE BEING CONFIGURATED TO RECEIVE SAID BOLTS, AND KNOB MEMBERS THREADBLY ENGAGING THE ENDS OF SAID BOLTS, SAID KNOB MEMBERS BEING IN ABUTMENT WITH SAID END PLATE.