Back to results
US 4,355,487 AGranted
Air-powered sander
AssigneeNone recorded
InventorsPeter Maier, Dieter Tschacher
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeNone recorded
InventorsPeter Maier, Dieter Tschacher
Estimating the term…
An air-powered sander is made up of a housing with a compressed air motor within it and designed for driving a sanding pad. The sander has a system for clearing dust, produced on sanding, from the pad. This system is made up of an impellor wheel freely turning on a motor shaft in the housing. On the two sides of the impellor wheel two groups of blades are present. A nozzle, joined with the airway for supplying the motor with compressed air, is used for directing at least one air jet against one group of the blades on the wheel. The other group of blades, on the other side of the wheel, is designed for producing a dust/air current for clearing sanding dust from the pad. For this purpose a dust take-up space is present extending from the pad to a position near inner ends of the second group of blades on the impellor wheel. There is furthermore a dust output airway extending from outer ends of the blades of the second group to a point at which the dust is forced out of the housing by way of an air current as produced by the impellor wheel.
In an air-powered sander with a housing, with a compressed air motor within said housing, with a pad movingly joined to said housing and designed to be moved by said motor for sanding a workpiece, and with a dust clearing system for dust produced on working with said sander, the improvement comprising wherein said sander further has an impellor wheel freely turningly bearinged in said housing and having first and second groups of blades thereon, a structure of said housing enclosing an input airway to said motor, a further structure of said housing forming an air nozzle joined with said input airway and designed for producing an air jet blowing against said first group of blades, a further structure of said housing forming a dust take-up airway extending from a position near said pad to a position near radially inner ends of said second group of blades on said wheel, and forming a dust output airway extending from radially outer ends of said second group blades to a point at which said dust may be forced out of said housing in an air current as produced by said impellor wheel.
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
No related US applications are recorded in the indexed filing history.
Specially designed for portable grinding machines, e.g. hand-guided: with oscillating tools
Machines, devices, or processes for grinding or polishing
Term ended 28 Jan 2001 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to an air-powered sander with a housing and a compressed air motor placed in the housing. The motor is designed for orbitally moving a pad which is joined to the housing. Because on sanding a workpiece dust is produced, the sander has a dust clearing or aspiration system.
In the case of such sanders as presently offered and marketed the dust clearing or aspiration system is not part of the sander in the limited sense of the word and in fact it takes the form of a separate aspiration unit with its own fan. Because it has to be kept joined to such a dust clearing system, the sander may not readily be moved from place to place in view of the connection with the outside dust aspiration system which is so large that it may not be moved along with the sander as it is used for sanding different parts of the work or different workpieces. In fact the dust aspiration system is so great in size that it has to have its own special position in the workshop and is furthermore responsible for increasing the costs of the plant in the first place.
In the case of sanders powered by electricity or compressed air there has been a suggestion to have an impellor wheel, used for aspiration of dust, on the motor shaft, so that no outside aspiration fan is necessary. However there is the shortcoming here that the rate of clearing dust does not take place at the desired rate when a great amount of dust is being produced because then the motor will only be turning at a low speed because of the heavier loading.
FIG. 1 is a lengthways section through an orbital sander powered by a compressed air motor and having a dust clearing or dust aspiration system with an impellor within its housing;
FIG. 2 is an axial view of the top side of the impellor wheel of the dust clearing blower of the orbital sander to be seen in FIG. 1;
FIG. 3 is an axial view looking towards the blower blade side of the impellor wheel of the orbital sander of FIG. 1;
As will be seen in FIG. 1, a compressed air-powered orbital sander has a housing made up of a top housing part 10 and a lower housing part 12, which are both made of molded synthetic resin and may, for their part, be made up of a number of separate parts. A compressed air-powered vane motor 14 is fixed in position between the two housing parts 10 and 12. Motor 14 has a motor housing 16, a motor shaft 18 and vanes 20 on shaft 18. The parts joining the two housing parts 10 and 12 are not detailed in the figure.
The top end of motor shaft 18 is supported in a bearing 22 on motor housing 16. A lower bearing 24 for the motor shaft is supported in a cylindrical casing 26 extending downwardly and forming part of the bottom of the motor housing.
On the free lower end of motor shaft 18 an eccentric 28 is keyed, the eccentric being taken up in a further bearing 30 for driving backing plate 40 to which sanding pad 34 is fixed. Sand paper may be fixed in a normal way to pad 34 by way of spring levers 36 and 38. Backing plate 40 is joined by way of an elastic skirt, forming part of lower housing part 12, for stopping its turning in relation to the housing.