WO2000027595A1

WO2000027595A1 - Auxiliary device for performing work above the head

Info

Publication number: WO2000027595A1
Application number: PCT/SE1999/002014
Authority: WO
Inventors: Johan Henrik Magnus Andersson
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-11-05
Filing date: 1999-11-05
Publication date: 2000-05-18
Anticipated expiration: 2001-05-05
Also published as: SE9803779D0; AU1436000A

Abstract

An auxiliary device for performing work above a user's head has a rod (16) with a mounting (19) for a tool. The auxiliary device comprises a waist support (10) to be fastened on the user's body at waist height and a rod holder (11) which is attached to or formed on the waist support. The tool mounting (19) is connected to a drive means (20) for displacing the tool mounting in the longitudinal direction of the rod. According to the invention, the drive means (20) is adapted to exert pressure upon the tool mounting (19) by substantially constant force in the direction away from the rod holder (11). This arrangement makes it possible to control the tool by the user holding his arms at waist height and breast height, and to provide the required upwardly directed even force with the aid of the drive means, thrust being taken up by the waist support.

Description

AUXILIARY DEVICE FOR PERFORMING WORK ABOVE THE HEAD

The present invention relates to an ergonomic auxiliary device for, inter alia, building workers when carrying out work at surfaces high above the workers' heads, for example ceiling work. From an ergonomic point of view, all work performed above the worker's shoulders and, in particular, high above his head, is inconvenient since such work involves improper strain on his shoulders, arms and back.

One object of the present invention is thus to pro- vide an auxiliary device which helps relieve the strain on all concerned muscle groups and which permits the work to be carried out at more comfortable and safe levels, although the worker is still standing on the floor. Another object of the invention is to provide an auxiliary device which is designed in such a manner that inconvenient strain on the worker's shoulders, arms and back is avoided, and strain is put on other less sensitive muscle groups and the parts of the body. Yet another object of the invention is to provide an auxiliary device that makes it easier for the user to press a tool carried by the auxiliary device by a substantially constant force against a surface above his shoulders and, in particular, high above his head, especially against a ceiling surface. These and other objects of the invention are achieved by an auxiliary device which is designed as stated in the independent claim. The dependent claims define specially preferred embodiments of the invention. Briefly, the invention relates to an auxiliary de- vice for performing work at levels above the user's head. The auxiliary device has a rod with a mounting for a tool. The auxiliary device comprises a waist support to be fastened on the user's body at waist height and a rod holder which is attached to or formed on the waist sup- port . The tool mounting is connected to a drive means for displacing the tool mounting in the longitudinal direction of the rod. The drive means is adapted to exert pressure upon the tool mounting by substantially constant force in the direction away from the rod holder. This arrangement makes it possible to control the tool by the user holding his arms at waist height and breast height, and to provide the required upwardly directed even force with the aid of the drive means, thrust being taken up by the waist support.

US-A-5, 613, 301 discloses a tree pruner which has a cutting device and a saw arranged at the top end of a rod, which is supported in a holder arranged on a waist belt. To drive the saw in an upward or downward direc- tion, there is a slide which is driveable along the rod which is connected to a pivoting driving grip by means of a link mechanism. The grip is pivoted by hand up and down in order to transmit this pivoting motion to the saw while at the same time the saw is pressed against a branch by the user pressing the rod and, thus, the saw in the direction of the branch. This prior-art pruner has several disadvantages which make it unsuitable for other uses than the intended one. Consequently, the pruner cannot be used to operate tools in the construction field, such as screw drivers, drilling machines, nail machines, grinding machines or paint tools. For an optimum function such tools must be pressed against the intended surface by a substantially constant force and without using muscular strength to prevent the user's shoulders and arms from being injured.

In the following, the invention will be described in more detail with reference to the accompanying drawings, in which

Fig. 1 is a schematic view of a first embodiment of an auxiliary device according to the present invention in two different working positions, Fig. 2 is a schematic view of a second embodiment of an auxiliary device according to the invention,

Fig. 3 is a cross-sectional view of the second embodiment , Fig. 4 is an embodiment of a waist support to be used in the auxiliary device according to the invention,

Fig. 5 is a third embodiment of an auxiliary device according to the invention,

Fig. 6 is a side view of a portion of the third em- bodiment , and

Fig. 7 is a cross-sectional view through a telescopic rod included in the third embodiment .

Fig. 1 shows an auxiliary device according to the present invention. The auxiliary device comprises a waist support 10, which is fastened round the worker's waist and hips by means of straps (not shown) . On the front side of the waist support protrudes a holder 11 which has an upwardly projecting pin 12. An angular sleeve 13 is slipped onto this pin. A tubular element 14 is inserted in the other end of the angular sleeve, and at the other end of the tubular element there is arranged an angular joining piece 15. From the upper end of the angular joining piece 15, protrudes a tube 16 which at its upper end has a longitudinal exterior reinforcement 17. Inside the tube 16, a slide 18 is arranged, which is fixedly connected to a fastening bracket 19 on the outside of the tube 16. The fastening bracket 19 and the slide 18 are connected to each other by a longitudinal wedge (not shown) , which extends through a longitudinal slot . The slot extends through the tube 16 and the reinforcement 17 and is parallel to the axis of the tube 16.

The slide 18 is connected to a piston rod in a pneumatic piston-and-cylinder assembly 20 which is arranged inside the tube 16. In the shown embodiment this assembly is pneumatically driven in order to move the slide 18 between its end positions (full lines and dashed lines, respectively, in Fig. 1) and in order to press the fasten- ing bracket by substantially constant force in the direction away from the rod holder 11.

In order to allow control of the auxiliary device in such a manner that a tool, for instance a drilling ma- chine, can be kept in position during a working operation, a handle 21 is rigidly connected to the angular joining piece 15. A control mechanism for the piston-and- cylinder assembly is placed in the handle. Moreover, control buttons for controlling the piston-and-cylinder as- sembly are arranged at the end or side of the handle.

When working with the auxiliary device, the tool is attached to the fastening bracket 19. Then one hand is put on the handle 21 and the other one in a suitable place, for instance on the angular sleeve 13. When the tool has been directed towards the correct point of engagement and at the correct angle, the piston-and- cylinder assembly 20 is activated by means of the control mechanism in the handle 21, so that the drilling machine is moved upwards by substantially constant force concur- rently with the drill penetrating into the ceiling surface where a hole is to be made.

When the work is completed, the air in the piston- and-cylinder assembly is let out, so that the slide 18 drops to its initial position. A return spring (not shown) may be used to facilitate this return. Then a new working procedure can start .

According to the invention it has become possible for the worker to hold both hands on a level with his trunk and chest and still carry out drilling work by sub- stantially constant force at a height high above his head. Since the auxiliary device is carried by the waist support 10 and the waist belt, the vertical forces are taken up by the worker's hips and waist. The pressure exerted on his shoulders and arms is relieved, which is most advantageous from an ergonomic point of view.

Figs 2 and 3 show another embodiment of an auxiliary device according to the present invention. In this case the auxiliary device is used, for instance, when painting a ceiling.

In the embodiment according to Fig. 1, a tube 16 is used, in which an inner slide 18 can be moved up or down to displace a tool mounting 19 vertically. In the embodiment according to Figs 2 and 3 , the tube has been made telescopic by having a lower tube part 22 and an upper tube part 23. The tube part 22 is pivotally connected to the waist support 10 by a schematically indicated ball- and-socket joint 24, so that the tube parts 22, 23 may be pivoted to a limited extent in different directions in relation to the waist support 10.

The free end of the tube part 23 serves as a mounting 36 for a paint roller, the handle of which is slipped onto the mounting, so that paint can be applied on, for instance, a ceiling surface located high up. To allow the paint roller to be pressed against and follow the ceiling as the tube parts 22, 23 pivot, the tube parts are tele- scopically arranged, as schematically shown in Fig. 3. The tube part 23 has a longitudinal slot 25 into which a guide pin 26 protrudes. For reinforcement purposes a reinforcement strip 27 may have been formed on the inside of the tube part 23. The guide pin 26 is rigidly attached to the lower tube part 22 and serves to prevent the two tube parts from rotating relative to each other. If rectangular tubes are used instead, the pin 26 and the slot 25 are, of course, not necessary.

At the upper end of the tube part 22, there is a winding mechanism 28 for a cord 29. The cord 29 extends over a roller 30 and down to a cord attachment 31 near the lower end of the tube part 23. Conveniently, the cord can extend in the slot 25. The cord is rolled up on a spindle 32 which is loaded to rotate in the roll-up direction for rolling up the cord 29 by substantially con- stant force. In principle, this arrangement can be compared to the winding mechanism which is used in blinds. By this arrangement the cord continuously tries to press the tube part 23 out of the tube part 22 by substantially constant force. As a result, the cord will be unrolled from the spindle 32 when the telescopic rod 22, 23 is compressed, as the paint roller is raised above the pain- ter's head by his arms and hands. When the paint roller is moved further away, the telescopic rod will be extended under the action of the cord, so that contact between the paint roller and the ceiling surface can easily be maintained. This embodiment of the auxiliary device according to the invention also improves the painting work ergonomi- cally since the lower end of the telescopic rod is supported by the waist support 10 and the painter carries out all the movements with his arms at waist and breast height and since the drive means 28, 29 allow the tool to be pressed outwardly against the ceiling surface by substantially constant force.

Fig. 4 shows one example of how the waist support 10 may be designed. The waist support has a broad arcuate plate 33 which has a holder 11. The lower part of a ball- and-socket joint may be fixed in a mounting hole 34 of the holder, if the waist support is used for the painting auxiliary device according to Figs 2 and 3. The pin 12 may be fixed in the same hole, if the waist support is used for the embodiment according to Fig. 1. Through holes 35 for a waist belt are formed at the outer ends of the plate 33.

Figs 5-7 show yet another example of an auxiliary device according to the present invention. A waist support 10 with holders 11 is attachable round the carrier's hips by means of straps. The end pins of a bracket 37 are inserted in the holders 11 so that the bracket extends a distance away from the hips, conveniently about 30 cm. At the outer end of the bracket, there are a lower and an upper holder 38 and 39 for a telescopic tube 40. Thanks to the presence of the bracket, it has become possible to move the tool mounting a distance away from the carrier's body. This means that the carrier does not have to bend his neck backwards to the same extent in order to watch the tool as if the bracket was missing. The bracket thus solves problems which may arise when bending the neck backwards. For better take up of torque, there is a set of straps 48 which is connected to the bracket 37 and which can be put on the carrier's shoulders and back.

At the outer end of the bracket there are also two handles 47 which extend obliquely upwards towards the carrier in order to be conveniently oriented for holding with both hands . In one handle there are control means for controlling the length of the telescopic tube, and in the other handle there are control means for controlling an electrically driven tool which is mounted on the telescopic tube.

The telescopic tube 40 has an outer tube 41 which in this example is cylindrical and an inner tube 42 which in this example is a rectangular tube. A guide means 43 is inserted at the upper end of the outer tube. The inner tube 41 extends through a square hole in this guide means so as to be prevented from rotating. However, it is possible to use other designs to prevent a relative rotation between the two tubes . Inside the lower end portion of the outer tube, an electric driving motor 44 is mounted. The output shaft of the motor is connected to a driving screw 45, preferably a buttress thread screw. The driving screw extends through the main part of the outer tube 41 and into the inner tube 42. A nut 46 is inserted in the inner tube. By shifting the direction of rotation of the electric motor, the telescopic tube 40 may be extended and shortened. The electric motor is connected to the driving screw by a torque limiter (not shown) , so that the inner tube is driven upwards by substantially constant force, which is determined by this torque limiter. The torque limitation may be provided by a separate slip clutch or a torque limiter which is built into the motor unit like in ordinary electric screwdrivers .

At the outer end of the inner tube 42, a conveniently designed tool mounting 47 is fixed. The bracket 37 may have mountings or room for arranging batteries or accumulators for supplying the electric current which is required for driving the telescopic tube and for driving the electric tool which is mounted thereon. The invention has been exemplified by three specific examples. The principle of invention may, however, be accomplished in many other ways within the scope of the claims. Furthermore, use can be made of either fairly rigid connections between the waist support and the rod device (cf. Fig. 1), or pivotable connections between these components (cf . Fig. 3) .

Claims

1. An auxiliary device for performing work above a user's head, comprising a rod (16; 22, 23; 40) with a mounting (19; 36; 47) intended for a tool, a waist support (10) to be fastened on the user's body at waist height and a rod holder (11) which is attached to or formed on said waist support, the tool mounting (19; 36; 47) being connected to a drive means (20; 29) for displacing the tool mounting in the longitudinal direction of the rod, c h a r a c t e r i s e d in that the drive means (20; 29; 44) is adapted to exert pressure upon the tool mounting (19; 36; 47) by substantially constant force in the direction away from the rod holder (11) .

2. An auxiliary device as claimed in claim 1, c h a r a c t e r i s e d in that the drive means comprises a pneumatic piston-and-cylinder assembly (20) .

3. An auxiliary device as claimed in claim 1, c h a r a c t e r i s e d in that the drive means comprises a constant winding mechanism with a cord (29) and a rolling-up device (32) therefor.

4. An auxiliary device as claimed in claim 1, c h a r a c t e r i s e d in that the drive means com- prises an electric motor (44) which is connected to a screw (45) for driving a nut (46) that is driveable along the screw, which is connected to the tool mounting (47) .

5. An auxiliary device as claimed in claim 2, c h a r a c t e r i s e d in that the control mechanism of the piston-and-cylinder assembly is arranged in a control handle (21) which is fixedly connected to the rod (16) .

6. An auxiliary device as claimed in any one of claims 1-5, c h a r a c t e r i s e d in that the rod holder (11) is formed as a ball-and-socket joint.