US 3850254 A
A drilling apparatus comprising a suction device for extracting drill chippings. The suction device includes a fan which is driven by a friction wheel operatively connected to the chuck of the drill. The suction channel includes a telescopic sleeve which surrounds the tool in the drill chuck.
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Description (OCR text may contain errors)
United States Patent [191 Hirdes SUCTION DEVICE FOR EXTRACTING DRILL CHIPPINGS  Inventor: Rudiger Hirdes, Tippelsberger Strasse, D-463 Bochum, Germany  Filed: July 6, 1973 21 Appl. No.: 377,051
 Foreign Application Priority Data  Field of Search 173/75; 175/209, 211, 213
[ Nov. 26, 1974 2,517,882 8/1950 Johnson .1 173/75 3,489,228 1/1970 3,781,024 12/1973 Ganser et al 173/75 Primary Examiner-James A. Leppink Attorney, Agent, or FirmArmstrong, Nikaido & Wegner [5 7 ABSTRACT A drilling apparatus comprising a suction device for extracting drill chippings. The suction device includes a fan which is driven by a friction wheel operatively connected to the chuck of the drill. The suction channel includes a telescopic sleeve which surrounds the tool in the drill chuck.
 References Cited UNITED STATES PATENTS 2,349,156 5/1944 Fischer 175/213 III I] 17 IL M 17" In SUCTION DEVICE FOR EXTRACTING DRILL CHIPPINGS BACKGROUND OF THE INVENTION 1, Field of the Invention The present invention relates to a drill comprising electric drive means, a drill chuck for the attachment of a tool, and a device for suctioning the drill chippings. The suction device is driven by the motor of the drill and is adapted to be manually operated jointly with the drill.
2. Description of the Prior Art Drills having suctioning devices are known in the prior art. The suction device consists of a fan wheel disposed directly on the armature shaft of the drive motor. This axially operative fan wheel is radially incorporated in a suction line leading from the drilling crown of the tool. In addition to high waste and shock losses, at low output a device of this type has a low quantity of air flow because of the low rotation speed of the armature and the fact that the losses increase in direction proportion to the square of the velocity of flow of the air in the proximity of the blades. Further disadvantages of this known type of drill are the small and therefore highly flow resistant air gaps between the suction openings on the drilling crown and the piece being worked, a possible concentration of the drill chippings in front of the fan, and possible poor conduction of the cooling air flow for the motor. Apart from these disadvantages, this hand drill can only be operated with very costly, hollow tools, and cannot be used in any other way, for example, for milling, sawing, grinding and polishing.
Another known drill has a suction device provided with separate drive means and with a suction sleeve connected to a suction line. This suction sleeve concentrically surrounds and seals the tool and comprises an extended extractor hood, which is rigidly secured to a supporting sleeve which rests on the piece to be worked. In addition to the second drive unit required for the suction device and the limitation of the range of movement of this drill, the closeness of the suction sleeve and the extractor hood is particularly disadvantageous as this results in only a relatively small flow of air being obtainable when the flow resistance is high. The quantity of air varies depending on the amount of waste due to leakage between the supporting sleeve and the suction sleeve.
SUMMARY OF THE INVENTION The object of the invention is to obviate the disadvantages of the prior art drills and, without adversely affecting other operational characteristics and applications, to provide an easy-to-handle drill comprising a device for extracting the drill chippings. It is intended that this drill should both permit the attachment of conventional tools and prevent any tendency to overload the motor.
According to the invention, the suction device comprises a compact dust exhauster releasably attached to the drill itself. The fan of the dust exhauster is driven via a friction wheel transmission gear in engagement with the chuck. This detachable suction device permits unlimited use of the drill, for example, for the variety of jobs done by the home handyman. Furthermore, the design of the drill does not have to be altered owing to the use of the friction wheel transmission gear. Also, it
is impossible to overload the motor because of the slippage of the friction wheel gear, which is inevitable.
To give the dust extractor a manageable form and to make it possible to readily attach it to and detach it from the drill, it is secured to the housing of the drill by means of a clamp. The transmission gear and the fan are arranged in a common dust exhauster housing designed to conform to the shape of the drill. To ensure maintenance-free operation, the gear wheels and the fan wheel are provided with self-lubricating friction bearings, for example, carbide bearings; the transmission step between the gear wheel connected to the friction wheel and the driving pinion of the fan alone, having a gear ratio of 1:2.
According to a particularly advantageous feature of the invention, the suction channel of the dust exhauster consists of a telescopic attachment piece utilizing a sealing sleeve to grip the end of the tool. The sleeve has a peephole on its periphery and an elastic sealing member on its front side facing away from the drill. In this way, the operator can keep both hands on the drill attachment without having to use two fingers to direct the suction channel onto the point of application of the tool. Furthermore, the entire drill hole is sealed by the sleeve resting on it, while the air flow is directed on the drill hole in a technically favorable manner, thereby ensuring that all the drill chips are suctioned directly into the suction channel and are not forced out through the peephole.
To provide the drill with an inexpensive, noncorrosive and simple structure, the fan wheel, the housing, the gear, the attachment piece and the sleeve of the dust exhauster are made of plastic, for example, a polyacetal, polyacetate, polyamide, an acrylic resin, or a polyethylene, and the housing is made of an impact resistant material.
Other objects, features and advantages of the present invention will be made apparent from the following detailed description of the preferred embodiment thereof provided with reference to the accompanying drawing, in which:
BRIEF DESCRIPTION OF THE DRAWING The drawing represents an embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, 1 designates the drill, 2 the chuck and 3 the tool, in this case, a bit. The dust exhauster 5 is releasably attached to the front part of the drill by way of the clamp 4. The dust exhauster 5 comprises a central part 5', a locking cap 5", and the suction pipe 5", which also serves as a cover. The friction wheel 6 and a gear wheel 7 integrally attached thereto, are arranged in the central part 5'. The gear wheel 7 is in engagement with a drive pinion 8. The drive pinion 8 is rigidly connected to a shaft 9, which is engaged in a formlocking manner with another shaft 9'. The fan wheel 10 is attached to the shaft 9 by means of a press-fit connection (not shown), or by means of an adjusting spring 9", as shown. The shafts 9, 9 are embraced by a spacer sleeve 11, behind which a filter l2 and a spacer disc 13 are arranged. The filter l2 prevents the fan wheel 10 from being damaged by large dust particles and is loosely pushed over the shaft 9 to provide rapid interchangeability. The bearings 14, 15, 16, of the friction wheel 6, the gear wheel 7 and the drive pinion 8, are in the form of self-lubricating friction bearings. The suction pipe 5" of the dust exhauster 5 faces towards the tool 3 and is provided with a telescopic attachment piece 17, the sleeve 17 of which embraces the tool 3. The sleeve 17 is provided on its periphery with a peephole 17" for the operator, and on its front side facing away from the drill l, with an elastic sealing member 17''. In this way, the sleeve can be made to abut in a sealed manner against the wall in question, so that the air is forced to flow through the peephole 17 into the suction channel. The suction channel 17 is advantageously in the form of bellows so as to be adaptable to the appropriate depth of penetration as the tool 3 penetrates a particular workpiece. The attachment part 17 is simply pushed over the suction pipe of the cover 5,
-which, in the same way as the locking cap 5", is se cured to the central part 5 by means of easily releasable clamp fasteners 18. At the lever of the blades of the fan wheel 10, the cap 5 is provided with a protective grill consisting of a plurality of bars.
As soon as the drill is switched on, the chuck 2 rotates the gear wheel transmission step consisting of the two gear wheels 7 and 8 via the friction wheel 6 disposed at its periphery, whereupon the fan 10 is driven in rotation at a rate corresponding to one translation of the chuck 2 on the gear wheel 6 and of gear wheel 7 on pinions 8. The air is then sucked via the peephole 17" of the sleeve 17', through the attachment part 17, and the suction pipe 5, into the central part 5 of the dust exhauster 5. The dust particles are caught by the filter 12 so that the air reaches the fan wheel 10 in purified form. From there it is forced outside by the locking cap 5".
The present invention may obviously be modified in various ways within the scope of the invention. For example, the dust exhauster housing may have a different, flatter, form and may be arranged in a different place, for example, above the drill. The gear for producing the requisite rotation rate of the fan may be a multi-step gear and the bellows represented may be replaced by a telescopic channel, preferably designed to be movable against the force of a spring. lt is also possible, if
perhaps not quite as advantageous, to use a gear wheel in engagement with the knurled chuck crown, in place of the friction wheel.
While the invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
What is claimed is-:
l. A drill apparatus comprising a drill including a housing, a motor, and a chuck for attaching a tool; and a suction means surrounding at least a portion of the tool for extracting drill chippings made by the tool, the suction means drivable connected to the motor and operable therewith, wherein the suction means comprises a dust exhauster including a fan wheel releasably attached to the drill, and a transmission for operably connecting the fan wheel and chuck whereby the fan wheel is driven by the chuck through the transmission.
2. A drill apparatus according to claim 1, including a screw clamp for attaching the dust exhauster to the housing of the drill and wherein the transmission and the fan wheel are positioned in a dust exhauster housing adapted to the shape of the drill.
3. A drill apparatus according to claim 2, wherein the transmission means and the fan wheel are provided with self-lubricating bearings.
4. A drill apparatus according to claim 1, wherein the suction channel of the dust exhauster comprises a telescopic means; and a sleeve which surrounds the tool at its end; said sleeve comprising a peephole on its periphery and having an elastic sealing member on its front side facing away from the drill.
5. A drill apparatus according to claim 1, wherein the fan wheel, the housing, the transmission means, the telescopic means and the sleeve of the dust exhauster are made of plastic.
6. A drill apparatus according to claim 1, wherein said transmission comprises a friction wheel operatively coupled to the chuck and a gear means coupling said friction wheel to said fan wheel.
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