WO1989006179A1

WO1989006179A1 - Means for mounting expansion-shell bolt

Info

Publication number: WO1989006179A1
Application number: PCT/SE1988/000705
Authority: WO
Inventors: Gavriel Bavli; Arne Karlsson
Original assignee: Gavriel Bavli; Arne Karlsson
Priority date: 1987-12-28
Filing date: 1988-12-27
Publication date: 1989-07-13
Also published as: SE8705158L; SE459910B; SE8705158D0

Abstract

The present invention relates to an expansion-shell bolt tool for inserting expansion-shell bolts into pre-drilled holes, said tool comprising a shaft with striking end (4) and driving end (5), a sleeve (6) being arranged axially displaceable on the driving end (5) and fitting a nut (3) applied on the expansion-shell bolt (2).

Description

MEANS FOR MOUNTING EXPANSION-SHELL BOLT

The present invention relates to an expansion-shell bolt tool, more specifically striking tool for inserting expansion-shell bolts into holes intended therefor, said tool comprising a shaft with striking end and driving end.

Nowadays machines such as reciprocating drilling machines or drill hammers are generally used for drilling holes and screwing on elements with the aid of expansion-shell bolts. Both rotary movement and striking can be switched on or off in the larger models whereas the smaller models can usually be used with or without the striking action. The actual insertion of the expan^¬ sion-shell bolt is usually carried out manually, however, using a sledge-hammer or the like. This is heavy and hazardous work and both the bolt and the surrounding material are easily da- maged.

Attempts to use a reciprocating drilling machine or drill hammer to insert the expansion-shell bolt inevitably result in the driving end slipping off the end of the bolt. Both the bolt threading and surrounding parts may then be damaged.

The object of the present invention is to provide an expansion- shell bolt tool which allows expansion-shell bolts to be inser¬ ted with the aid of conventional reciprocating drilling machi- nes, drill hammers and similar machines, without risk of the ex¬ pansion-shell bolt being damaged and without the driving end slipping off the end of the bolt.

This is achieved with the expansion-shell bolt tool described in the introduction which according to the invention is characteri^¬ sed by a sleeve which is axially displaceable on the driving end.

According to a preferred embodiment of the invention the sleeve is spring-loaded.

Locking means are preferably arranged to rerain the sleeve or- the driving end of the tool, above a lower end position. According to one embodiment of the invention a helical spring is arranged between a shoulder on the shaft of the tool and a washer, said washer being arranged to abut against said sleeve and shaped to be retained by said locking means for the sleeve, e.g. when exchanging the sleeve.

This design of the tool according to the invention permits ex^¬ pansion-shell bolts to be driven into holes intended therefor in a surface, and even through holes in the design elements or other units to be fitted onto the expansion-shell bolts, where the nut shall be applied on the expansion-shell bolt. The sleeve thus guides the nut so that the driving end cannot slip off the expansion-shell bolt during insertion. While guiding the nut, the sleeve also prevents it from being turned and moving along the expansion-shell bolt. Furthermore, the nut is not damaged since the sleeve is arranged axially displaceable on the shaft. Since the sleeve is arranged with spring movement on the shaft, it is retained on the nut during the vibration, this ensuring control of the bolt.

A great advantage gained with the device according to the pre¬ sent invention is the saving in time required for inserting ex¬ pansion-shell bolts, which is reduced to a fraction of that re- quired for manual fitting, particularly when assembling rooves or ceilings.

Although an important advantage of the present invention is that expansion-shell bolts can be fitted with the aid of commercially available strike-generating machines, the expansion-shell bolt tool can also be used for manual insertion of expansion-shell bolts with the aid of a sledge-hammer or the like. Here, exactly as is the case with machine operation, the sleeve ensures that the driving shaft is guided on the bolt, thus preventing damage to expansion bolt, nut and surrounding surfaces.

According to one embodiment of the invention the shafr is divi¬ ded into two parts joined together via a roller coupling, for instance. This allows smaller machines in which the rotary func¬ tion cannot be disconnected can also be used for inserting ex¬ pansion-shell bolts. The functin of the coupling is such that the part of the part of the expansion-shell bolt tool closest to the machine rotates but only transmits strokes or vibrations to the part of the expansion-shell bolt tool located closest to the expansion-shell bolt. In this embodiment the expansion-shell bolt tool must of course be replaced after insertion of the bolt with a sleeve shaft or equivalent, permitting the nut to be tightened on the bolt.

Additional advantages and features of the invention will be re¬ vealed in the following detailed description with reference to the embodiments of the invention shown in the drawings, in which

Figure 1 is a cross-sectional view through an expansion-shell bolt tool according to the invention,

Figure 2 is a cross-sectional view taken along the line A - A in Figure 1, and

Figure 3 shows an alternative embodiment of the expansion-shell bolt tool according to the present invention, adapted for use on smaller machines in which the rotary function cannot be dis- connected.

Figure 1 shows a cross section through an expansion-shell bolt tool in accordance with the invention', generally designated 1, applied on an expansion-shell bolt 2, partially shown, with a nut 3 screwed on. The expansion-shell bolt tool 1 is only pati- ally shown, i.e. without machine attachment since this is depen¬ dent on the machine in which the tool is to be used or, ^'alterna¬ tively, if it is to be used for manual insertion of expansio - shell bolts .

The expansion-shell bolt tool 1 is provided with a shaft section 4 in which the machine attachment is arranged, and also a driv¬ ing part 5. A sleeve 6 is arranged axially displaceable on the driving part, the size of said sleeve being adapted to the size of the nut. The driving part 5 is suitably designed as a rec¬ tangular section which fits into standard box-spanners, and is provided with locking means in the form of a spring-ball 7 of conventional type to prevent the sleeve being unintentionally released from the driving part.

In the preferred embodiment shown here the sleeve is loaded by means of a helical spring 8 on one side abutting a shoulder 9 providing a junction between the shaft part and the driving part, and on the other side abutting a washer 10 which in turn rests against the sleeve 6. In the embodiment shown a washer 11 is also shown between the shoulder 9 and the helical spring 8 to ensure satisfactory abutment of the spring and eliminate any risk of the spring creeping up onto the shaft part. The spring- ball 7 also provides insurance against the washer slipping off the driving part due to spring pressure which exchanging sleeves or when the tool is stored without a sleeve.

With the design of the expansion-shell bolt tool according to the invention, the sleeve 6 guides the tool on the nut 3, thus ensuring that the tool will not slip off during vibration. Neither the bolt nor the surface below will thus be damaged. Since the sleeve is axially displaceable on the driving part, the nut will not be loaded when the bolt is struck or vibrated into the hole and thus neither the nut nor the screw threading can be damaged.

The spring 8 functions so that, throughout the operation, the sleeve is held down over the nut 3 and safely guides the tool. Furthermore, the force used is so low that no damage can occur.

Figure 2 shows a cross section through the driving end 5 of the expansion-shell bolt tool, and through the sleeve 6. In the e - bodiment shown the driving end has quadratic cross section, which is an advantage since standard box-spanners can then be used. However, the invention is not limited thereτ-.c. The essen^¬ tial feature is that a sleeve arranged axially displaceable or- the driving part shall be able, without turning, to move up and down on the driving part.

Figure 3 shows an embodiment of the expansion-shell bolt tool according to the present invention for use on machines without a disconnecting function for the rotary movement, i.e. generally smaller machines. The shaft 12 is divided into two parts, with a rotary coupling 13 arranged between the two parts 14 and 15. In the embodiment shown, the part 15 to be fitted into the machine is provided with a pin 16 which can be fitted into a conven¬ tional chuck, and a pin 17 for disconnectable connection to the other part 14 of the shaft. A spring-ball 18 of conventional type is arranged on the pin with locking screw and helical spring. This is only indicated in the drawing in conjunction with the ball. The ball passes in a peripheral recess in a hollow in the part 14 into which the pin 17 on the shaft part 15 fits. Between the two shaft parts 14, 15 is a ball-bearing 19. A ball-bearing is shown in the drawing but this can advan¬ tageously be replaced with a slide or axial bearing. Allowing the two surfaces to slide on each other without intermediate bearing, eliminates the risk of the bearing seizing under heavy loading. When the tool is used on a reciprocating drilling machine, for instance, the shaft part 15, fitted in the machine, will rotate whereas only the strokes or vibrations will be transmitted to the other part 14 of the shaft.

Of course the structural elements can be modified without depar¬ ting from the basic concept of the invention. The locking mem^¬ bers may be different, for instance, or the coupling between the two parts of the shaft in the embodiment shown in Figure 3.

Furthermore, in certain cases the spring may be omitted,and' re¬ placed by stops or the like to achieve a limited path of move^¬ ment for the sleeve.

Claims

C l a i m s

1. An expansion-shell bolt tool for inserting expansion-shell bolts into pre-drilled holes, said tool comprising a shaft with striking end and driving end, c h a r a c t e r i s e d by a sleeve (6) which is axially displaceable on the driving end (5) and fits a nut (3) applied on the expansion-shell bolt (2) .

2. An expansion-shell bolt tool as claimed in claim 1, c h a r a c t e r i s e d in that the sleeve (6) is spring- loaded .

3. An expansion-shell bolt tool as claimed in claims 1-2, c h a r a c t e r i s e d by locking means (7) to retain the sleeve on the driving end (5) .

4. An expansion-shell bolt tool as claimed in claims 1-3, c h a r a c t e r i s e d in that a helical spring (8) is arranged between a shoulder (9) on the shaft and the sleeve (6) .

5. An expansion-shell bolt tool as claimed in claims 1-4, c h a r a c t e r i s e d in that the striking end (4) is pro¬ vided with a machine attachment for a reciprocating drilling machine, drill hammer or equivalent vibration-generating machi- nes.

6. An expansion-shell bolt tool as claimed in claims 1-5, c h a r a c t e r i s e d in that the shaft (12) is divided into two parts and that the two parts (14, 15) are joined to- gether via a rotation coupling (13) , this permitting the tool to be used in machines in which the rotary movement cannot be dis¬ connected.