CA1078619A

CA1078619A - Suction housing

Info

Publication number: CA1078619A
Application number: CA294,255A
Authority: CA
Inventors: Miksa Marton
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-01-03
Filing date: 1978-01-03
Publication date: 1980-06-03

Abstract

IMPROVED SUCTION HOUSING
Abstract of the Disclosure An improved suction housing for rotary sanders comprising a suction housing for connection to a drive head and including a back-up pad mounted within said housing for rotation therein; said pad having a plurality of elongated apertures through the surface thereof for alignment with apertures of like formation in an abrasive disc secured to the bottom of said pad; said housing including a bottom wall spaced above and overlying a substantial portion of the upper surface of said pad and a collection chamber contiguously formed with said bottom wall including side walls and a top wall spaced substantially above said pad, said chamber occupying only a small portion of the surface area of the pad to thereby apply suction on the pad on a concentrated area; and an exhaust suction pipe extending from the collector chamber.

Description

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This invention relates to rotary sanders a~d in particular to an improved suction device for use in such a sander. ~ - `
Substantial problems have been encountered in grinding fiberglass such as in automobile bodies. When ground, fiberglass is very sticky and it cuts into small string-like portions and plugs up air channels in conventional vacuum housings. It also sticks to automobile bodies and it is very hard to clean the surface on which it i~ stuck~ When grbund ;;
with a coarse disc, fiberglass also brleaks up into small pieces and chunks and it is difficult to draw the heavy particles through normally available air suction channels. Further, flberglass normally has to be cut with a high speed machine and the additional centrifugal force applied by such machines tends to throw the material away from the ground surface and from the area of suction.
Another problem involved Witll normally available vacuum housings is that if an operator is applying suction with a pipe from a large chamber over the grinding mechanism, the suction is not concentrated powerfully to one point where it is needed.
In other words, to a great extent, most of the time when grinding is being done, only part of the back-up pad and abrasive disc is placed on the surface to be ground. The remainder of the back-up pad is held upwardly and is away from the ground surface. With pipe from a large suction chamber over the grinder, the large heavy particles ground from the surface tend to fall out and settle on that point and the suction being dispersed only carries the lighter particles away from the ground surface and into the vacuum apparatus.

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SUMMARY OF THE INVENTION
In the present apparatus, most of the vacuum apertures in the back-up pad are covered and the suction or vacuum is directed in the main to the spot that the operator is grinding 50 that the operator has a powerful suc~ion on the spot that is being cut by the abrasive material.
In accordance wi~h one broad aspect of the present inventionr there is provided an improved suction housing for rotary sanders comprising a suctlon housing for connection to a drive head and which includes a back-up pad mounted within ~he housing for rotation therein. The pad has a plurality of elongated apertures extending completely through the surface thereo and are adapted for alignment with apartures of like formation in an abrasive disc which is secured to the bottom of a pad. The housing includes a bottom wall spaced above and ~ -ovexlying a substantial portion of the upper surface of the pad and a collection chamber contiguously formed with said bottom wall including side walls and a top wall which is spaced ~ubstantially above the pad. The co:Llection chamber occupies only a small portion of the surace area of the pad to thereby apply suction on the pad in a concentrated area and an exhaust -suction pipe extends from the upper wall of the collection chamber for connection to a vacuum applying apparatus.
In the present invention, the suction housing is so designed a~ to reach almost to the very edge of the back-up pad and the vacuum pipe occupie~ an important place on top of the suction housing. All grinders turn to the right and drive the ground material to the rîght as well thereby throwing all the ground material to the rlght when the material goes beyond the ..
periphery of the grinding pa~. In the present invention suction i8 applied completely through the back-up pad an~ in order to prevent the ground material to fly at a tangent beyond the back-up . ,, . . . , . . ........... . . . . , , : .
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pad, a collection chamber .is provided immediately above the edge of the pad which is applied to the surface to be ground.
Dust particles rom their own weight stick to the left side of the apertures under the influence of centrifugal force and therefore the weight of the ground material ~ends to go to the lPft. With an angular disposition of the suction pipe from right to left, the vacuum draws the material through the holes in the same direction as the material originally intended to take. Th~ pswer and direction of the vacuum together with the weight of the ground material work together with the centriugal force to draw the material better and faster from the sanded surface through the vacuum tube.
The invention is illustrated in the accompanying drawings in which:
. Figure 1 is an exploded view in perspective of the improved vacuum housing assembly;
Figure 2 is a view of the bottom surface of the housing, and Figure 3 is a perspective view of the housing in assembled form.
Re~erring to Figure 1, the assembly generally indicated at 10 includes a vacuum housing 12, back-up pad 14 and abrasive disc 16~ Housing 12 comprises a peripheral wall 18 having a bottom wall or plate 20 (Figure 2) and a central upstanding collar 22 adapted to be secur~d to a drive housing 24 (Figure 3) by means o~ a strap or the like 26. As seen in all figures, the housing 12 includes a collectox chamber 28 which includes an opening 30 in the plate 20, side walls 32 and a top wall 34 from which a vacuum pipe or exhaust pipe 36 extends at an angle.
30 . The back-up pad 14 has an upper surface 38 of solid material such a~ a hard plastic and has an aperture 4 0 threaded to engage the abovementioned drive member. The pad 14 has a -3~

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plurality of apertures 42 which are elongated in form and extend completely through the back-up pad as shown in the small ~
cut-away portion thereof and which lie~very-near~the extreme outer edge of the pad so a3 to be in registry with similar holes 44 in the abrasi~e disc 16 sh~wn in Figure 1. Disc 16 i~
applied to the bottom surface of pad 14 by centering-means;and i5 held thereon by the snap ring 46 which engages the fabric skirt 48 on the abrasive disc 16 and which secures the skirt into the peripheral groove S0 in the pad 14 as shown in Figure 3.
The disc 14 is pro~ided with an upstanding flange 52 which fits within the depenaing portion 54 of the side wall 18 of the housing 12 to prevent any outside air from entering the confines of the housing and this is enhanced by means of a resilient band 56 which is pIaced on the outside of the suction chamber and which extends downwardly o~er the skirt thereof to effectively seal off any outside air to be drawn into the confines of the chamber.
The plate 20 (Figure 2) is spaced slightly above the upper surface of the apertures 42 so that they are not completely sealed off as some ground material may not be completely drawn in by the collector chamber 28 due to the high speed of rotation of the pad 14 and some material may pass by the chamber on the first revolution but be picked up on the next.
It will be appreciated that with the collector chamber 28, most of ~he suction applied through exhaust pipe 36 is concentrated in the area where it ~s mostly needed, the area being ground by the operator. it has been found that in concentrating the ~acu~ in this manner, all ground material i~ instantly drawn through the paper, ba~k-up pad and int~ the suction chamber 28 to preven~ the material from clogging the .:., , '' ' " ' ' ' ' ' ' ' ' . ~' ' . ., ' ', ' .:
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suction holes in the pad and disco - -... -. .. . . - . . . .
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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An improved suction housing for rotary sanders comprising a suction housing for connection to a drive head and including a back-up pad mounted within said housing for rotation therein; said pad having a plurality of elongated apertures through the surface thereof for alignment with apertures of like formation in an abrasive disc secured to the bottom of said pad; said housing including a bottom wall spaced above and overlying a substantial portion of the upper surface of said pad and a collection chamber contiguously formed with said bottom wall including side walls and a top wall spaced substantially above said pad, said chamber occupying only a small portion of the surface area of the pad to thereby apply suction on the pad on a concentrated area; and an exhaust suction pipe extending from the collector chamber.

2. An improved suction housing according to claim 1 including a circular flange on the upper surface of said back-up pad spaced inward from the peripheral edge thereof and adapted to fit within the vertical wall of said housing.

3. An improved suction housing according to claims 1 and 2 including an air seal band positioned around the outside of the vertical wall of said housing and extending downwardly over the terminal edge of the back-up pad to inhibit air drawn into the space between the upper portion of the pad and the collector chamber of said housing.