DEVICE AND METHOD FOR PLACING SCREWS AND PRESSURE DISTRIBUTION MEMBERS

The invention relates to a device and method for placing screws and pressure distribution members.

In current practice insulation and roof covering is arranged on flat or slightly pitched roofs by fastening thereof by means of so-called pressure distribution members and screws. This operation is often carried out manually and must be carried out directly on the roof surface. This is an undesirable situation.

A system is known in which a placing apparatus, embodied as a battery-powered screwdriver with extended shaft, places the screws and pressure distribution members. The screws and pressure distribution members must however here be positioned manually at the correct location on the roof, whereby an undesirable situation is still obtained in respect of working conditions .

The use of known devices causes problems such as bad working conditions, difficult maintenance, lack of easy access in order to remedy obstructions or jamming, and inflexibility where the use of various sizes and forms of pressure distribution members and screws is concerned.

An object of the invention is to improve the above stated known devices and to obviate as many of the above mentioned problems as possible.

This object is achieved with the device according to the invention, comprising:

- a positioning member for positioning the pressure distribution members;

- a guide means for guiding the pressure distribution

members to the centre of the positioning member;

- a screw guide for guiding the screws to the positioning member; and

- a driven screwing shaft for screwing the screw through the pressure distribution member which can be moved up and downward between a screw guide-releasing position and a screwing position.

In a preferred embodiment according to the invention the screws and pressure distribution members are supplied from working height to the fastening point by means of separate guide means. A flexible device hereby becomes possible for different sizes and forms of screws and pressure distribution members. The screw guide consists of a tubular member with minimal curvature with which both short and long screws can be inserted at working height and guided to the positioning member. The pressure distribution member is guided to the positioning member by means of a guide chute in the form of a tube or partly cut-away oval duct which is adapted to the pressure distribution members for handling. This tube or duct functions here as a type of slideway or guideway. In the case of a different size or form of pressure distribution member the guide chute with the positioning member can be changed by means of a simple screw or clamp fixing. Tightening or loosening the screws takes place by means of driving the screwing shaft. During tightening the drive is pushed downward by the user such that the free end of the screwing shaft, with a fitting bit mounted thereon, engages on the screw and this latter is placed together with the pressure distribution member. In order to optimize processing speed the number of operations must be as few as possible. This is not the case in known devices.

This is resolved with the preferred embodiment according

to the invention, wherein the device is provided with a gas spring with which the drive is moved from the end position, in which a screw is placed, back to the starting position in which a subsequent screw can be placed. An additional aspect of the present problem in known devices is that pressure distribution members are not always positioned correctly, whereby the screw with pressure distribution member is not arranged properly or is not arranged at all. In a preferred embodiment according to the invention the positioning member of the device is provided with an upright edge which is adapted to the size and form of the pressure distribution members, whereby this pressure distribution member from the guide chute is brought to a stop at the correct position. This edge is preferably fixedly connected to the guide chute, whereby the guide chute and the positioning member can be changed in simple manner in the case a different size or form of pressure distribution member has to be used. A further aspect of the present problem in known devices relates to jamming and obstruction of the screw, possibly in combination with the pressure distribution member, and the limited application of longer screws in particular.

In a preferred embodiment according to the invention the screw is inserted at working height in a preferably tubular screw guide with which the screw is guided to the extended guide hereof, or the transition guide, into which the screwing shaft guide also debouches. Passage of the screws to the pressure distribution member is hereby realized, wherein the bit on the free end of the screwing shaft can engage on the head of the screw. The transition guide comprises a gradual transition from the screw guide, placed substantially- parallel to the screwing shaft guide, to the extension of

this screwing shaft guide. Screws with a length of up to about 17 cm can herein be handled. In the unlikely event of an obstruction or jamming occurring, a cover plate can be removed from the transition guide, whereafter the obstruction or jamming can be easily remedied.

A further aspect of the problem in known devices is the fact that, after insulation and/or roof covering has been arranged, the correct position of arrangement of the screw with pressure distribution member is not always easy to determine.

In a preferred embodiment according to the invention the device is provided with a rule for determining the mutual distance between successive screws. The correct position can hereby be determined in simple manner without a further position determination being required in a stooped posture.

A further aspect of the problem in known devices relates to the determination of depth of the screw to be arranged with pressure distribution member, wherein a screw which is not inserted far enough can result in damage, as can a screw which is arranged too deeply.

In a preferred embodiment according to the invention the device is provided with a stop with which the drive is stopped at the desired depth when a screw with pressure distribution member is being arranged. This achieves that the screws are arranged at uniform depth.

A further aspect of the problem in known devices relates to the placing of screws with pressure distribution members on the edge of a roof close to for instance a wall. Known devices require a certain distance to such an obstacle as a result of mechanisms for feeding screws and pressure distribution members and/or the support or support plate on which wheels are optionally mounted.

In a preferred embodiment according to the invention the

wheels are placed on the device such that the whole device can be placed close to an obstacle such as a wall for the purpose of arranging screws with pressure distribution member. With known devices a screw can be placed in practice up to 20 cm from an obstacle, while with the device according to the present invention a further screw with pressure distribution member can be placed up to about 5 cm from such an obstacle.

A method according to the invention comprises the following steps of:

- placing the device at the correct position/

- supplying a pressure distribution member by means of a guide chute;

- positioning a pressure distribution member by means of a positioning member;

- supplying a screw by means of a screw guide;

- arranging or removing the screw by means of a screwing shaft in a screwing shaft guide provided with a drive; and

- returning the drive with the screwing shaft from the screwing position to the screw guide-releasing position.

Screws and pressure distribution members can be fastened in simple manner by means of a method according to the present invention, thereby improving working conditions.

Further advantages, features and details of the present invention will be further described with reference to the figures, in which:

- figure 1 shows a front perspective view of the embodiment according to the present invention;

- figure 2 shows a rear perspective view of the embodiment of figure 1;

- figure 3 shows a detail of the embodiment of figure 1. An embodiment according to the present invention is shown in figure 1 and relates to a device 2 for placing

screws S and pressure distribution members P for fastening insulation and roof covering. Device 2 comprises a screwing shaft guide 4 which is provided at the top with a holder 6 in which drive 8 can be placed. Drive 8 with the screwing shaft arranged therein is pressed downward into the screwing position or end position by means of a handle 10. During placing of a screw S with washer P the passage of screws out of screw guide 14 is obstructed by the screwing shaft. When the user presses handle 10 downward, a telescopic spring 12 is compressed. After placing of screw S with washer P this telescopic spring 12 returns drive 8 to the starting position or the screw guide-releasing position, in which a new screw can be placed. A screw is supplied by means of a screw guide 14 which is provided at the free end with an infeed part 36, whereby the screws can be supplied at working height. This working height is about 1 metre. Screw guide 14 is arranged substantially parallel to screwing shaft guide 4, optionally at an angle a. as shown in figure 2, and as a result of the force of gravity carries the screw to the extension of this guide, or transition guide 16, where the screw is placed in line with the screwing shaft guide. Transition guide 16 is provided with a cover plate 18 which is fastened in simple manner by means of screws or in other manner. Access to the transition guide can hereby be gained in simple manner in the case of an obstruction or jamming of the screw. After placing of the screw via transition guide 16 the drive 8 can be moved downward by means of handle 10, wherein the screwing shaft engages on the screw for the purpose of arranging it. As soon as the screw has been arranged to a sufficient depth, drive 8 will come to lie against a stop 20 by means of holder 6 in order to hereby arrange all screws at uniform depth. The washers are arranged by means of a guide chute 22, with which the washers are placed from working height in a positioning

member 24. If desired, the washers and/or screws can be stored in a supply holder 26, wherein this holder can consist of a number of individual parts and is fixed to the device by means of a support 28. On the underside the device is provided with a shaft 30 on which are mounted wheels 32. In the preferred embodiment these wheels 32 are mounted on the device in non-swivelling manner so as to hereby ensure a linear movement of the device, and thereby a linear placing of the screws with washers. These wheels 32 can of course also be provided for swivelling purposes. Device 2 is also provided with a measuring rule 34 in order to thereby determine the correct distance between the last placed screw with washer and the subsequent screw with washer to be placed. This rule 34 can be adjusted such that the desired distance between the screws can be adapted by the user to the materials to be used and to requirements. The device is preferably embodied as much as possible in stainless steel (SS) in order to avoid rust formation. Guide chute 22 is provided on the infeed side with a receiving opening 40 for simplifying supply of the washers. Guide chute 22 is connected to device 2 by means of a number of supports 42. In the shown preferred embodiment cover plate 18 of transition guide 16 is fixed by means of screws 44. Cover plate 18 can of course also be fixed in other manner. Rule 34 can also be fixed to the device by means of a screw 46 or by means of other fastening means. In addition, telescopic spring 12 is also fixed to the device in the preferred embodiment by means of a number of screws 48. It is here also the case that telescopic spring 12 can also be attached to the device in other manner.

In the preferred embodiment according to the present invention the positioning member 24 has a round form and

consists of an upright edge which is preferably attached fixedly to guide chute 22. Positioning member 24 can of course also be mounted releasably on guide chute 22. A washer supplied via guide chute 22 comes to lie in positioning member 24 and is stopped as a result of the upright edge and laid at the correct position for the purpose of fastening. If another shape or size of washer has to be used, guide chute 22 and positioning member 24 are disconnected by means of a screw, clamp or otherwise arranged connection. In the shown embodiment guide chute 22 consists of a bent U-shaped tube or duct which is left open on one long side so as to hereby have a good view of the washers. Access to guide chute 22 is hereby also ensured. Situated on the underside of device 2 is a support 50 on which is mounted shaft 30 with wheels 32. A support 52, to which a rule 34 is fixed, is also mounted on this support 50.

The screwing shaft driven by drive 8, which is placed in holder 6, is placed in screwing shaft guide 4. In the shown embodiment the infeed part 36 for the screws and receiving opening 40 for the washers are placed adjacently of each other to make feeding of these materials by a user as easy as possible. This feed can of course also take place at another location. The angle (X between screwing shaft guide 4 and screw guide 14 can thus for instance be made even smaller in order to allow the screw to undergo a more vertical movement. In the preferred embodiment the screwing shaft guide 4 is embodied by means of a duct profile, but can of course also be embodied as a tube.

Figure 3 shows transition guide lβ wherein cover plate 18 is removed by releasing screw connection 44. The transition from screw guide 14, from which the screw is carried to transition guide 16, to the axis of screwing shaft guide 4 can be clearly seen. In the shown situation the

screwing shaft 60, which is driven at the one outer end by drive 8, is in the starting position in which a screw can be supplied. By means of screw guide 14 and transition guide 16 this screw is placed on the washer which is supplied by means of guide chute 22 and is positioned with positioning member 24. The user then pushes screwing shaft 60 downward, whereby bit 62 placed at the free outer end of screwing shaft 60 engages on the head of the screw and will tighten it. After tightening the drive 8 will be returned to the starting position by means of telescopic spring 12. The- user can then tilt the device slightly by means of support 50, whereafter the whole device can be displaced to the following position using wheels 32 placed on a shaft 30. This following position can be determined using measuring rule 34, whereafter the user supplies a washer and then a screw via the corresponding guides. Figure 3 further shows that the position of wheels 32 relative to positioning member 24 with associated guide chute 2 is such that device 2 can be placed close to an obstacle, such as a wall, whereby a screw and associated washer can be arranged about 5 cm from this same obstacle.

The skilled person will be able to make many modifications on the basis of the different aspects of the above described embodiment. The rights sought are defined by the appended claims.