Adjustable Slot Suction Box Cover

Abstract

An adjustable slot cover adapted to be mounted on a suction box or pipe having openings therein in communication with a source of suction. The cover includes a base which is rigidly mounted to the suction pipe. The base includes alternate lands and slots with the slots in communication with the openings in the suction pipe. A plurality of wear strips are slidably mounted on receiving land portions of the cover with dovetail or T-shaped interengagements retaining the wear strips in position. Axial positioning of the interengaging surfaces along with the lateral width of the strips determines the portion of each wear strip which covers a portion of an adjacent slot. The dovetail or T-shaped opening in the wear strips can be located off center so that strips can be turned end for end to change the width of slot. The wear strips are interchangeable so that adjustability of slot widths is thereby achieved.

Description

BACKGROUND OF THE INVENTION

In felt manufacturing procedures a suction pipe or box is often utilized. The suction pipe is connected to a source of suction and has a number of openings on its periphery to subject the material to vacuum as desired in the manufacturing process. Additionally, a vacuum pipe cover is employed over which the material can be placed and handled. The cover is designed to permit communication between the material being worked on and the openings in the suction pipe to utilize suction in the operational processes.

The conventional type of suction pipe cover is made in one or two pieces. The cover has a rigid body portion and slots positioned between separated portions on the body to provide communication to the openings in the suction pipe. The cover is rigidly mounted to the suction pipe. In some designs, the slot widths are fixed in dimension and there is no means for adjustment of the slot width to adjust the amount of access the suction openings have to the material on the surface of the cover. In other designs, the machine must be shut down in order to readjust the slotted lips in order to get a new slot width. With radical changes constantly being made in the newer press felt designs, it is difficult, time consuming and uneconomical to make changes for proper operation. As a result, the vacuum conditioners are not operated properly for all types of felt designs presently in use.

There is no question that a need is present for a means of quickly and efficiently adjusting the slot widths on a suction pipe cover to accommodate all types of felt designs and insure proper operation of the machinery.

SUMMARY OF THE INVENTION

With the above background in mind, it is among the primary objectives of the present invention to provide a multi-piece suction pipe cover which permits rapid and efficient adjustment of slot widths for particular felt designs. The cover is designed so that it can easily be adjusted to a variety of different slot widths depending upon the felt material to be handled. The adjusting of the slot widths can be carried out quickly and efficiently and the top wear surface of the cover can be changed rapidly and efficiently when desirable.

The present design includes the base which is fastened to the suction pipe or box. The base has been slotted to a maximum size of a slot or slots for the intended use. Wear strips of varied widths are fitted to the base in an interengaging manner such as by the use of dovetailed surfaces or T-shaped surfaces. In this manner the strips can only be removed by sliding them in respect to the fixed base. The interengaging portion are varied axially with respect to the wear strips so that by interchanging and reversing the strips it is possible to adjust the width of one or more of the slots in the cover base. End stops or deckle fingers are supplied at each end of each slot to assure end seals.

The cover may be designed so any number of the lands are adapted to receive wear strips to adjust adjacent slots. By using various widths of wear strips, further adjustments in slot width can be accomplished in addition to the axial positioning of the interengaging surfaces on the wear strips and the lands of the cover base. Furthermore, the whole top wear surface may be formed by wear strips which can be replaced quickly, easily and much cheaper than with known previous designs.

Therefore, in summary, an adjustable slot cover is provided which is adapted to be mounted on a suction box or pipe having openings therein in communication with the source of suction. The cover includes a base having means thereon for mounting the base to a suction pipe. Surfaces are on the base forming alternate lands and at least one slot with the slots in alignment with the openings in a suction pipe when the base is mounted thereon. A plurality of wear strips are provided with each strip adapted to be removably mounted on a land. Finally, interengageable surfaces are on at least one land adjacent to a slot and each strip with the interengageable surfaces positioned so that when a predetermined pattern of strips are removably mounted on the lands and interengaged therewith the position of the strips will define the exposed width of the slots thereby permitting adjustment of the slot sizes by the arrangement of strips on the base.

With the above objectives and summary of the invention in mind, reference is had to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is an exploded perspective view of the slot cover of the invention and a suction pipe for mounting the slot cover thereto;

FIG. 2 is a top plan view of the slot cover of the invention and a suction pipe therefor in assembled condition with arrows showing the direction of felt travel thereover;

FIG. 3 is a fragmentary sectional view of the slot cover of the invention showing the configuration of the slot cover between slot openings;

FIG. 4 is a fragmentary top plan view of the slot cover of the invention mounted to a suction pipe;

FIG. 5 is a fragmentary sectional elevation view thereof taken along the plane of line 5--5 of FIG. 4;

FIG. 6 is a fragmentary top plan view of an alternate embodiment of the slot cover of the invention mounted to a suction pipe;

FIG. 7 is a fragmentary sectional elevation view thereof taken along the plane of line 7--7 of FIG. 6 with an arrow showing the direction of travel of felt across the assembly; and

FIG. 8 is a sectional side elevation view of a further alternate embodiment of the slot cover of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-5 show one embodiment of the slot cover 20. A suction pipe 21 is depicted on which the slot cover is adapted to be mounted. The suction pipe 21 has a hollow central chamber 22 open at one end 23 for connection to a source of suction and sealed at the opposite end 24 by means of an end cap 25 affixed thereon. Open end 23 can be affixed in any conventional manner to the source of suction such by a threaded interengagement with a corresponding threaded outer surface on end 23.

Two parallel rows of aligned openings 26 are on the peripheral surface of the pipe 21. Slots 26 provide communication between the exterior surface of pipe 21 and the interior chamber 22 thereof for withdrawal of air therefrom by the source of suction through open end 23. Additionally, a pair of aligned rows of parallel bolt holes 27 are on the outer peripheral surface of pipe 21 for assembly with the slot cover in the manner described below.

The suction pipe 21 may be constructed in a manner in which end plates 28 and 29 are welded to cover the opposing ends of the pipe respectively and nipple 30 extends axially from end plate 28 and nipple 31 extends axially outwardly from end plate 29. End cap 25 then closes off nipple 30 in any conventional sealing manner such as by welding. Therefore the entire suction pipe is welded air tight except for slots 26 over which slot cover 20 is placed and, of course, the open end air outlet portion 23. A pump, eductor or some other similar removal source is connected to end 23 and the only opening remaining to permit entry of air is through slots 26 on the top of the pipe. Bolt holes 27 are naturally sealed when cover 20 is fastened to pipe 21.

The slot cover includes a base portion 32, a plurality of wear strips 33 further identified as 34, 35 and 36, and a number of deckle fingers or end stops 37.

The base portion in the desired configuration can be constructed in a convenient manner such as machinery from one piece of phenolic laminate or it may be machined or molded from polyethylene material. No portion of base 32 forms a wear surface for the felt handling during operation. The entire wear surface is provided by the wear strips 33 and the deckle fingers or end stops 37.

Base 32 has a central curved undersurface 38 which conforms to the outer surface of the suction pipe 21. The central arcuate portion 38 terminates in a pair of opposed longitudinal end base portions 39 with each end base portion containing a plurality of holes 40 along its length. Each hole 40 is drilled oversize so a threaded screw 41 passes through to the threaded opening 27 in the pipe. Screws 41 threadedly engaged with openings 27 in the suction pipe to rigidly mount base 32 to the outer surface of pipe 21 and to prevent air from passing through openings 27 in pipe 21.

The upper surface of base 32 is formed of alternate lands and slots. As shown, there are three lands 42 which define a pair of parallel slots 43 therebetween. At the base of each slot 43 there are a plurality of aligned openings 44 which communicate with openings 26 in the outer surface of suction pipe 21 to provide communication between the slots 43 and the source of suction.

Defining slots 43 are three lands 45 which are upward projections of base 32. The lands 45 have trapezoidal shaped projections 46 extending upwardly therefrom. Projections 46 from dovetail projections for engagement with similar dovetail recesses 47 in the undersurface of each wear strip 33. Therefore, when a wear strip 33 is slid axially onto projection 46 the projection 46 will mate with the similarly shaped trapezoidal recess 47 to fix the wear strip in position. The beveled dovetailed surfaces 46 on projection 45 and on the surfaces of wear strip 33 forming recess 47 interengage to hold the wear strip in position.

As shown in FIGS. 1-5, projections 46 are of the same shape and size so that any of the three wear strips 33 which have identical shape and size recesses 47 may be positioned on any of the lands 45. In this manner, the wear strips can be interchanged to facilitate adjustment of the slot widths.

Adjustment is accommodated in two manners. First, the wear strip may have a wider lateral dimension as, for example, wear strips 34 and 36 are wider than the third wear strip 35. Therefore, when a wider wear strip is connected to a particular projection in a dovetailed arrangement a portion of the strip will extend into the slot 43 as shown in FIGS. 4 and 5. Similarly, in FIGS. 4 and 5, it can be noted that strips 35 and 36 do not have the same projection into slot 43 so that the slot 43 between wear strips 35 and 36 is wider. By interchanging strips 34, 35 and 36, the slots 43 can be adjusted as desired.

In addition to the difference in lateral dimension of the three wear strips 33, and additional adjustment feature is provided by the positioning of dovetail recess 47. In wear strip 35, the recess is substantially centered on the undersurface of the wear strip whereas in respect to wear strips 34 and 36 the recess is axially off-center thereby providing a greater portion of the wear strip on one side of the interengagement recess than on the other. Therefore, when these wear strips are interchanged or reversed in direction with respect to lands 45, the slots 43 will be adjusted in width accordingly. It can be readily seen how the versatility in positioning of recesses 47 and in the actual lateral widths of the wear strips 33 can be utilized in adjusting the width of slots 43 which are exposed to the exterior of the cover. There are a variety of different arrangements of positioning for the recesses 47 and for the widths of the wear strips 33 to provide an infinite variety of slot size adjustments for slots 43.

Once the wear strips 33 have been positioned as desired on base 32 end stops or deckle fingers 37 are slid into position at the ends of slots 43 to form end seals. Each deckle finger 37 has an upwardly standing body portion 48 and a flange base portion 49. The flanged base portion is engaged by retaining surfaces on the lands 45 and the wear strips 33 so as to be held in position and to close of the ends of each slot 43.

Deckle fingers 37 are slidable axially within slots 43 so that they can be moved to correspond to the width of a web of felt material passing across the top of the assembly. In this regard, particular reference is made to FIGS. 5 and 2 of the drawings with arrows depicting the direction of travel of the felt material 50. By adjusting fingers 37 to a position in engagement with the edge of the felt material 50 on both sides of the material as it passes over a slot, a sealing arrangement is effected. The deckle fingers 37 form a seal so that all of the air passing through slots 44 in the cover and through openings 26 in the pipe must pass through the felt material. Naturally, when a different width of felt material is employed, fingers 37 may be slidably adjusted accordingly to form a similar seal. Since the felts in general use are relatively tight in structure, air does not readily pass through and therefore tends to restrict the air flow and build up a vacuum inside the pipe assembly. In the above manner, the deckle fingers regulate the effective open length of the slots and prevent air leakage from a slot opening which may be outside the edge of the felt.

Attention is directed to FIGS. 2 and 3 of the drawings which particularly show the configuration of the base of slots 43 in cover 20 which are positioned between slots 44 through which air passes to the pipe. These intermediate lands or islands 51 are tapered to an apex, as shown, and cover the metal ribs 52 between slots 26 on pipe 21. The tapered shape of islands 51 assist in keeping felt material from building up on the flat metal ribs 52 and consequently causing streaks in the material.

An alternate embodiment is shown in FIGS. 6 and 7 of the drawings. Suction pipe 21 has slot cover 20' mounted thereon. The mounting is accomplished by means of angle brackets 53 one on each side of cover 20'. Each angle bracket 53 is connected to vacuum pipe 21 by means of threaded bolts 54 which are in threaded interengagement with receptive threaded holes 27 in pipe 21. The undersurface of the head of bolt 54 engages with the bracket surface holding the bracket to the suction box 21. A plurality of bolts 54 are spaced along the length of cover 20' to assure that the base 55 of the cover is held in tight engagement with suction pipe 21. As shown, angle bracket 53 bears against base 55 and against suction pipe 21 to hold the base in fixed position.

Base 55 has three lands 56, 57 and 58 extending upwardly therefrom. The lands are spaced to provide a pair of slots 59 and 60 therebetween. The central land 57 forms an upper central wear surface and is of one piece construction with the remainder of base 55. In contrast the outer two lands 56 and 58 terminate in a pair of upward T-shaped projections 61 and 62 respectively which extend the length of cover 20'. Slidably mounted on the T-shaped projections 61 and 62 are a pair of wear strips 63 and 64 respectively. The undersurface of each of the wear strips 63 and 64 contains a T-shaped recess which corresponds in size to T-shaped projections 61 and 62. Interengaging surfaces as shown on projections 61 and 62 and on wear strips 63 and 64 hold the wear strips in position and permitting only sliding movement for removal of the strips from the remainder of cover 20'. The interengagement is achieved between the outer surface of flanges 65 of projection 61 and the surrounding surfaces 66 of strip 63 and the outer surfaces of flanges 67 of projection 62 and the surrounding surfaces 68 of strip 64 respectively. Once again as in the previously discussed embodiment, the outer configuration particularly the lateral width of each wear strip 63 and 64 determines the amount of the wear strip which extends into the slot opening thereby determining the size of the slot opening to the top surface of cover 20'. An additional feature which contributes to adjustment of slot size is the positioning of the recesses in the undersurface of wear strips 63 and 64 particularly in regard to whether or not it is aligned with the central axis. By shifting the location of the recess, the mating of the T-shaped recess with the T-shaped projections determines the position of the wear strip and in turn the amount of the wear strip which extends over slots 59 and 60 to cover a portion thereof. In this manner, by providing a number of different sized wear strips and a number of different wear strips with off-set recesses in their undersurfaces, a great variety of slot width variations can be accomplished.

It should be kept in mind that although a one-piece base and projection embodiment is shown in FIGS. 6 and 7, the T-shaped projection could be in the form of a metal T-bar bolted to the remainder of the base 55. Additionally, the embodiment of FIGS. 6 and 7 shows a central land portion without a removable wear strip for adjustment and the embodiment of FIGS. 1 to 5 shows all three land structures with removable and adjustable wear strips. Furthermore, it can be readily envisioned how the projections can be located on the wear strips and the recesses in the land surfaces for interengagement in a similar manner as described above. A great number of different combinations of one-piece land structures along with replacement wear strip structures can be combined as desired.

Additionally, although there are three land portions on base 55 and two intermediate slots in both of the embodiments shown, it can readily be envisioned how it is possible to construct the cover with any number of land portions with appropriate slots located in between each adjacent pair of land portions of a cover, for example, one slot between two land portions.

It can also be readily envisioned that cover 20 can be designed to fit a variety of different configurations for the suction base member. This would naturally include suction boxes as well as suction pipes. For example, FIG. 8 depicts a further alternate embodiment for a cover wherein cover 69 has a trapezoidal shaped undersurface 70 to accommodate a corresponding trapezoidal shaped suction box member. In all other respects, the cover would operate as in the previously discussed embodiments. The configuration of the undersurface of cover 69 is designed merely to accommodate its connection to the appropriate suction source member.

In summary, the removable wear strips provide a means for immediate adjustment of slot width at all times to control the vacuum on a wide range of felt designs. Additionally, individual replacement of wear strips is possible rather than the necessity of replacing an entire cover when it is desirable or necessary.

Thus the above discussed objectives of the invention, among others, are effectively attained.

Claims

I claim:

1. In combination:

a suction pipe, surfaces of said suction pipe defining at least one longitudinal opening into the suction pipe interior;

an adjustable slot cover for said suction pipe, said cover including a base, means on said base for mounting the base to said suction pipe in fixed position, surfaces of the base forming alternate longitudinal lands and defining at least one longitudinal slot between said lands, said slot being in alignment with said suction pipe opening; and,

a plurality of interchangeable wear strips, each of said wear strips slidably engaging a land of said base; said wear strips each comprising an upper wear surface of predetermined width and an undersurface portion including means thereon for removably interlocking and interengaging with a land, said interlocking means being located off center with respect to said wear surface so that the spacing between the wear strips engaging alternate lands can be altered to vary the exposed width of said slot.

2. The invention in accordance with claim 1 wherein each of said wear strip undersurface portions includes a longitudinally extending trapezoidal recess and each of said lands has a complementary trapezoidal shape in section.

3. The invention in accordance with claim 1 wherein each of said wear strip undersurface portions includes a longitudinally extending "T"-shaped recess and each of said lands has a complementary "T"-shape in section.

4. The invention in accordance with claim 1 wherein there are three lands on the base, three wear strips interchangeably mounted on the three lands, and the three lands with the three wear strips mounted defining two longitudinal slots therebetween.

5. The invention in accordance with claim 1 wherein there are deckle fingers removably mounted on the base and positioned at each end of the slot to form end air seals.

6. The invention in accordance with claim 1 wherein at least one L-shaped clamp has surfaces bearing against the base of the cover and surfaces bearing against the suction box and a passageway therethrough to receive a bolt, the bolt threadedly interengaged with an opening in the suction pipe to rigidly hold the clamp to the cover and the suction pipe and retain the cover in fixed position with respect to the suction pipe.

7. The invention in accordance with claim 1 wherein the base is formed of polyethylene material.

8. The invention in accordance with claim 1 wherein the base is formed of a phenolic resin material.