Rotary tool suction housing

A vacuum housing for a rotary tool, particularly a hand-held tool such as a grinder, consists of a tubular casing concentrically positioned around the tool. The casing features a telescopic nose portion.

BACKGROUND OF THE INVENTION 
The invention relates to tools such as grinders, drills, sanders and the 
like and in particular to a vacuum housing for such tools. 
In numerous fields of use, serious dust problems are created by the use of 
rotary tools and this is particularly so in the use of high-speed, 
pneumatically operated grinders and sanders which normally operate in the 
15,000 to 30,000 rpm range. Such fields of use are in the automotive 
industry where hand held grinders are used to trim fiberglass body panels, 
sand such panels and generally trim edges, clean holes and cut pieces out 
of fiberglass. The minute particles of glass fiber created in such 
operations is a serious health hazard to the tool operators even though 
the operator wears safety goggles and a mask and in some cases a special 
suit. Very sharp glass fiber particles still enter the operator's body 
with the result that substantial discomfort is created through itchiness, 
etc. 
Numerous attempts have been made to develop different types of suction or 
vacuum devices for carrying away such particles but these vacuum devices 
generally have been ineffective due mainly to the fact that the point of 
vacuum is too far removed from the point of work. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, a substantial advancement in 
vacuum devices for high speed tools is provided in the form of a vacuum 
housing for the tool and the housing is so constructed that the vacuum 
source is the point of work of the tool concerned. In the following 
disclosure, the invention is described by way of example in combination 
with a high speed linear tool with a grinding bit therein but the 
invention is equally applicable to drills, sanders and the like. 
In accordance with one aspect, the invention relates to a vacuum housing 
for a rotary tool and is adapted for connection to a vacuum source. The 
housing comprises a tubular casing of a greater diameter than the body of 
the tool and is adapted to be concentrically positioned about the body of 
the tool and detachably secured thereto. The tubular casing includes a 
nose portion mounted thereon for telescopic movement relative to the 
casing itself, the nose having an opening for protrusion therefrom of an 
operating bit of the tool and spring means are provided intermediate the 
nose portion and the casing to bias the nose in an extended position.

Referring to FIG. 1, the housing shown generally at 10 is adapted to be 
detachably secured to a tool 12, in the case illustrated, a high speed 
pneumatically operated rotary tool having a tubular body 14, a chuck 16 
and a detachable bit such as an abrasive grinder 18. As illustrated in the 
linear exploded view of this figure, the tool 12 fits inside the housing 
10 and is operated by means of air pressure directed through a line 20 and 
connected to the tool 12 by means of fitting 22. The tool is operated by 
means of a pushbutton 24 located on one wall of the tool body. 
The housing 10 comprises a tubular casing 26 of substantially the same 
length as the tool 12, the casing 26 having a plurality of longitudinal 
ribs 28 spaced around the interior surface of the casing wall as shown 
more clearly in FIGS. 2 and 3. The uppermost rib 28a is threaded to 
receive at least one or preferably two set screws 30 which, when the tool 
is placed in position inside the casing 26, are screwed inwardly to engage 
a pair of cooperating sockets 32 in the body 14 of the tool 12. It will be 
appreciated that release of these screws allows the tool to be quickly 
slipped out of the casing 26. 
The casing also is provided with a pivotal trigger 32 which, through a 
free-floating pin 34, serves to operate the actuating button 24 on the 
body of the tool. 
The vacuum housing 10 incorporates a telescopic nose portion 36 having 
sufficient movement indicated at T in FIG. 2 to allow the grinding bit to 
be inserted fairly deep into the work and still have the point of vacuum 
adjacent thereto. Additionally, the resiliency of the nose portion 36 
provides an automatic depth gauge to the bit when grinding a depression or 
hole. 
As shown in FIGS. 1 and 2, nose portion 36 has a tubular section 38 that 
slidably fits within the casing 26 and a converging wall 40 terminating in 
a tubular flange 42 and bead 44 surrounding the opening 46 where dust 
particles and the like may be drawn into the housing under vacuum force. 
As shown in FIG. 2, the nose portion 36 is biased towards an extended, 
outward position by means of a coil spring 48 and its outward movement is 
limited by a pair of elongated U-shaped retainers 50 which are secured at 
their outer ends to the cone 38 and, at their inner ends engage the rear 
portion of respective rubs 28 as shown clearly in FIG. 3. 
At this point, it will be appreciated that when the grinding bit 18 is 
rotated at high speed the vacuum presented at the housing opening 46 is 
immediately adjacent the work and by pushing inwardly towards the work on 
the body of the casing 26, the nose cone 36 will retract allowing the bit 
to go deeper into the work. 
FIG. 5 shows an alternate form of mounting the nose 36 onto the casing wall 
26 by means of a pair of longitudinal grooves 52 in the tubular portion 38 
of the nose and set screws 54 mounted on the wall of the casing. The 
terminal end of the casing 26 is provided with a peripheral flange 33 and 
the outer end of the converging wall 40 is provided with a similar 
peripheral flange 35. A coil spring 37 of frustoconical shape is mounted 
between the two flanges 33, 35 to thereby urge the nose portion 36 
outwardly. It will be observed that the structure of FIG. 5 eliminates the 
elongated U-shaped retainers of FIG. 1, allowing more space for movement 
of the nose 36. 
The opening 46 of the nose portion 36 may be provided with a screen 56 to 
prevent large particles or chunks of fiberglass or the like from entering 
the inner part of the casing. 
In FIG. 7, a deflecting device is shown comprising a collar 58 adapted to 
fit around and be rotatable on the flange 42 of the nose portion 36. The 
collar 58 carries a semi-circular shroud made up of a pair of quarter 
panels 60 and 62 connected together by spring means 64. While using a 
grinding bit or a drum sander, the deflector will overlie the operating 
tool and will prevent debris from being thrown upwardly away from the 
vacuum opening 46. However, due to the spring connection 34 between the 
quarter panels 60 and 62, the shroud may be folded upwardly in the 
direction of the arrows so that the shroud will not limit downward 
movement of the grinding tool onto the work surface. 
Returning to FIG. 1, the casing 26 is connected to a flexible vacuum hose 
66 by means of a stepped connecting collar 68 and the airline 20 which 
lies in the center of the vacuum hose branches off therefrom at some 
distance from the housing 10. 
It will be appreciated that operation of the tool within the casing 26 
provides a vacuum source at the point of work and the debris is drawn by 
the power of the vacuum around the body of the tool intermediate the outer 
surface thereof and the inner wall of the casing. I have found in practice 
that the reciprocal working of the nose 36 in the casing 26 and in 
particular the working of the spring 48, tends to detach any heavy 
particles of work that may clog in around the spring and this action 
releases those pieces to be drawn into the vacuum apparatus. 
The housing of the present invention does not interfere either with the 
tool bit or with the operator. In operation, the operator finds it easier 
to use the tool inside the casing as high speed rotary tools tend to get 
very cold due to the temperature of the tool being lowered by the velocity 
of the driving air. It will be appreciated from FIG. 2 that the tool can 
be quickly released from the casing simply by unscrewing the two set 
screws 30 and dropping the body of the tool out through the back of the 
casing.