EP2489473A2 - Screwdriver system with cartridge screw attachment - Google Patents

Abstract

The attachment (20) has a two-part housing (22) provided with a guiding channel for guiding a screwdriver tool. The guiding channel extends along a longitudinal axis (L) of the housing. A connecting section (44) allows a releasable connection with a powered impact screw driver (30). A receiving section (24) receives a magazine belt with screws at an end turned away from a coupling section (42), where the belt is moved by a drive unit. The housing comprises housing parts (22a, 22b) that are axially movable relative to each other in a direction of the longitudinal axis. An independent claim is also included for a screw driver system comprising a propelled impact screwdriver.

Description

The invention relates to a Magazinschraubvorsatz for a powered impact wrench for driving screws, especially drywall screws, and a nutrunner system comprising a powered impact wrench and a magazine screw attachment.

In addition to manually moving screwdrivers, motor-driven screwdrivers in numerous variants and sizes are known from the current state of the art. With their help, the screwing in of screws compared to the manual method is greatly facilitated and accelerated.

However, the manual picking up of the screw, as well as the attachment of the screw on the object to be screwed and the attachment of the screwdriver on the head of the screw take a relatively large proportion of the working time when screwing a screw. In order to shorten this working time, especially in the professional application, magazines are used in practice, which can accommodate several screws and are placed on the screwdriver or integrated into it. These include screw magazines with screw bands and straps for screw supply and - supply, as for example from the DE 19 23 712 C Magazinschraubvorsätze, where screw supply container are placed separately from the screwdriver and the screws are fed through a pneumatic hose with compressed air to the screwdriver, as in the DE 21 13 310 A1 discloses, or Magazinschraubvorsätze in which the screws are fed to their isolation by gravity of the screw blade, such as from GB 1 115 126 known. In the latter, however, the screwing is possible only in vertical working position down, since the supply of the screws is dependent on gravity.

In a further development, as in the DE 1 199 199 B is disclosed, engaging in the Schraubenzuführungsschiene, this is provided depending on the screw closing and opening lock, which regularly tracks the screws, so that the spatial position of the screwdriver with magazine on the transport of the screw to the screwdriver blade has no effect. According to the disclosure of DE 1 199 199 B the magazine attachment shown therein may be integrally formed with a screwdriver or be screwed as a separate unit to the transmission of a conventional screwdriver.

Also from the DD 210 641 B is a separate Magazinschraubvorsatz known, but should not be placed on a screw drive, but on a motorized hand drill or a stationary drill. For this purpose, the disclosed magazine screw attachment has a self-releasing dog clutch for combination with a drum magazine.

For many applications in the professional artisan sector, however, is a simple screwdriver or a drill with Screwing function is not sufficient, since the prescribed torque of the screwdriver for screwing in the screw at comparatively high resistances of the object, in which the screw is to be screwed, no longer sufficient. For such applications, the principle of an impact wrench for screwing and drilling with a rotary impact mechanism is known from practice, such impact wrench are used, inter alia, when it is necessary to produce or solve high-strength threaded connections.

The function of the rotary impact mechanism is based on the idea of temporarily storing the drive energy of an engine and periodically emitting it to an output shaft within a very short working phase. As a function of the pulse duration, these periodically emitted rotational pulses produce a significantly higher resultant drive torque than would be possible given a constant torque curve. On the drive side, the system receives kinetic energy in the form of torque and speed. This kinetic energy is stored intermediately in an assembly, for example in a spring or in a rotating mass.

The storage process ends whenever a control mechanism ensures that the stored energy is delivered via a hammer on an anvil. For this purpose, both the anvil and the hammer of the striking mechanism on impact jaws, wherein the hammer comprises a flywheel, which is formed by the massive part of the hammer. If this mass is accelerated, the kinetic energy can be applied to the anvil be transmitted. The anvil stands in a rotationally stable connection to both the output and the screw connection. By means of the control mechanism, a time-limited delivery of energy to the anvil is ensured.

In Schlagwerk two work phases are distinguished, in the first phase, the energy is collected and stored, while in the second phase, the stored energy is released again. The input quantities of torque, speed and number of pulses determine the energy stored in the first phase. Thus, for example, at a higher stroke rate of the striking mechanism, the first phase is shortened in time and it can be stored correspondingly less energy, since the engine can only apply a predetermined torque and thus the duration of the storage process is crucial.

In the second phase, the duration of the energy release is also crucial. If the stored energy is delivered to the output in a shorter time, the resulting torque peak is higher than with a comparable longer stroke duration. Usually, in a typical torque curve of an impact wrench, energy is temporarily stored over a relatively long period of time, which in turn is delivered abruptly to the output in a very short period of time. In the case of impact no torque is generated at the output between the torque peaks.

By this configuration, high tightening and loosening moments are possible in a compact design. Nevertheless, the reaction moment, that has to catch the worker with the impact wrench, only the moment that is necessary to accelerate the rotating hammer mass in the hammer mechanism, or to tension the spring. It is relatively low compared to the output torque.

The basic principle of an impact wrench is also in the DE 43 01 610 A1 disclosed.

The present invention has an object to further improve the working method of screwing for the user by shortening the working time, and at the same time to facilitate.

This object is achieved by a magazine screw attachment according to the invention for a powered impact wrench for driving screws, in particular drywall screws, wherein the magazine screw attachment has a housing with a guide channel extending along a longitudinal axis of the housing for guiding a screwing tool and having a connecting portion which is adapted to it is to make a detachable connection with a powered impact wrench.

Such a combination of a magazine screw attachment with a powered impact wrench can combine the advantages of the impact wrench with those of a magazine screwdriver.

This is particularly noticeable in drywall, where plasterboard and the like must be attached to a Unterlattung or a sheet metal profile. If the screw, which penetrates comparatively quickly into the material (for example plasterboard or wood), encounters resistance, for example a battening or a sheet-metal profile, then the speed drops sharply in a screwdriver without a hammer, which is why the screwing takes much longer, or must be canceled. In the present invention, however, the screw can be screwed by means of the impact, wherein the impact energy is higher by a multiple and the screwing is much faster. The use of a magazine screw attachment leads to a further time savings when screwing, since it is no longer necessary to separate each drywall screw, to attach to the material and set up the screwdriver to then screw it.

In a particular embodiment, the magazine screw attachment can have a receiving section for receiving a magazine strap with screws at its end facing away from the connecting section. In this embodiment, the Magazinschraubvorsatz is limited to the supply of screws by means of a Magazingurtes. Alternatively, however, it is also conceivable, according to the general principles of the present invention, to provide other magazine configurations for the magazine screw attachment which is connectable to the powered impact wrench.

It can also be provided that the housing of the magazine screw attachment is essentially formed in two parts, wherein the two housing parts in the direction of the longitudinal axis of the housing are axially movable relative to each other and wherein a drive unit of the Magazinschraubvorsatzes is provided in a movement stroke of the housing parts relative to each other Magazing belt relative to the magazine screw attachment is able to move.

Such a magazine strap may for example be made of plastic and a plurality of screws, for example, 50 screws, uniformly spaced over its length, wear. Furthermore, the magazine belt can be spirally inserted in the region of the receiving section. Alternatively, the magazine strap can also be guided unwound via a guide on the magazine screw attachment. In each case, a screw to be introduced is aligned coaxially with the guide channel for guiding the screwdriver tool, so that the screwdriver tool with the screwdriver blade can attach directly to the screw head of the screw to be introduced and screw it into the corresponding object.

To screw in the user presses the impact wrench together with the magazine screw attachment at the point against the material in which the screw is to be screwed, where he wants a screw. As a result, an axial relative movement of the two housing parts to each other is achieved until the screw tip of the screw to be screwed is applied to the material. During the screwing process, the moved axially relative to each other, so that the screw over its entire shaft length can be screwed into the material. If the impact wrench is removed from the material together with the magazine screw attachment after the screwing procedure has been completed, the two housing parts are returned to one another, for example with the aid of an elastic element which acts as a return element.

The drive unit, which is able to move the magazine belt to bring the following screw (to the just screwed screw) in coaxial alignment with the guide channel, can either the movement stroke of the two housing parts relative to each other (drive stroke) or the opposite return movement (return stroke) use to move the magazine strap as desired. In the first case, an intermediate unit for energy storage can be used for this purpose, wherein the kinetic energy of the drive stroke of the housing parts is temporarily stored relative to each other and can only be released once the screwdriver tool has returned to its original position (out of engagement with the screw).

For a further description of a conceivable drive unit is based on the German patent DE 1 923 712 B directed.

The present invention further relates to a screwdriver system comprising a powered impact wrench and a magazine screw attachment with the aforementioned features, wherein the impact wrench a housing with a recorded therein Schlagwerk has. Such a striking mechanism can be driven by means of a drive and comprise a drive shaft connected to the drive and a drive shaft which can be coupled to a tool holder, wherein a torque can be transmitted from the drive shaft via the impact mechanism to the output shaft. The impact mechanism is set up to transmit a rotary impact to the output shaft if required. The impact wrench also has on the output side a coupling portion for releasable coupling with the connecting portion of the magazine screw attachment.

In a further development of the present invention, the coupling section can comprise a sleeve-shaped housing section which at least partially surrounds the output shaft of the impact wrench and has connection means on its outer circumference which can cooperate with corresponding connection means on the connecting section of the magazine screw attachment in order to releasably connect it with the impact wrench. The connecting means or corresponding connecting means may comprise, for example, radial or axial projections which can be received in corresponding recesses, can cooperate with corresponding projections or engage behind such to provide an axial and / or radial securing. Furthermore, the connecting means may for example comprise a clamping ring with a clamping screw, or an internal thread, which cooperates with an external thread, and the like.

Finally, the invention also relates to the use of a magazine screw attachment in conjunction with a powered impact wrench, the magazine screw attachment comprising a housing having a guide channel extending along a longitudinal axis of the housing for guiding a screwdriver tool and having a connecting portion for making a detachable connection with the powered impact wrench.

The invention will be described below with reference to the accompanying figures, which illustrate a preferred embodiment of the invention. The person skilled in the art will expediently also individually consider the features disclosed in the drawing, the description and the claims in combination and combine these into meaningful further combinations.

The invention is not limited to the design of impact wrenches shown in the embodiment. Rather, it also extends to screwdrivers with pulse cell, pneumatic screwdrivers and hydraulic screwdrivers, which are also to be regarded as impact wrench in the sense of the present invention and in particular in the sense of the claims.

Figur 1

eine Seitenansicht eines erfindungsgemäßen Schraubersystems umfassend einen angetriebenen Schlagschrauber und einen damit verbindbaren Magazinschraubvorsatz;

Figur 2

eine Draufsicht auf das erfindungsgemäße Schraubersystem gemäß Figur 1;

Figur 3

eine Seitenansicht des erfindungsgemäßen Schraubersystems gemäß Figur 1, wobei der Magazinschraubvorsatz von dem angetriebenen Schlagschrauber gelöst ist; und

Figuren 4a und 4b

eine isometrische Ansicht des angetriebenen Schlagschraubers gemäß den Figuren 1 bis 3, wobei Figur 4b eine Detailansicht eines in Figur 4a gezeigten Details darstellt.

They show schematically:

FIG. 1

a side view of a screwdriver system according to the invention comprising a driven Impact wrench and a magazine screw attachment connectable therewith;

FIG. 2

a plan view of the inventive screwdriver system according to FIG. 1 ;

FIG. 3

a side view of the inventive screwdriver system according to FIG. 1 with the magazine screw attachment detached from the powered impact wrench; and

FIGS. 4a and 4b

an isometric view of the driven impact wrench according to the FIGS. 1 to 3 , in which FIG. 4b a detailed view of an in FIG. 4a showing details shown.

In FIG. 1 an inventive screwdriver system is shown, which is generally provided with the reference numeral 10. The screwdriver system 10 according to the invention comprises a magazine screw attachment 20 and a powered impact wrench 30, wherein the magazine screw attachment 20 in the in FIG. 1 illustrated embodiment is connected to the powered impact wrench 30.

The powered impact wrench 30 according to the illustrated embodiment is designed as a hand-held impact wrench having a hand strap 12 which is releasably connectable to the housing 32. Furthermore, the illustrated is driven Impact wrench 30 electrically operated, the drive of the impact wrench 30 is supplied by a releasably connected accumulator pack 14 with electrical voltage. Of course, however, the present invention is not limited to an impact wrench with a battery pack, but also extends to mains powered impact wrenches.

The housing 32 of the impact wrench 30 may be formed in one or more parts, in practice often multi-part housing, which are formed by half shells or the like, are preferred. In this case, a part 34 facing the accumulator pack 14 forms the gripping region for the hand of a user, while the part 36, which is essentially vertical for receiving the drive, for example in the form of an electric motor (not shown), and optionally a transmission (not shown) , serves. The drive of the impact wrench 30 can be activated by actuation of an actuating element 38 (displaceable pushbutton), whereby usually the drive is activated only when the actuating element 38 is kept pressed down.

In the region of its output 40, the impact wrench 30 is connected to a magazine screw attachment 20 according to the invention. Of course, the impact wrench 30 can also be operated without a magazine screw attachment 20.

The magazine screw attachment 20 comprises a substantially two-part housing 22, wherein the housing parts or housing units 22a and 22b, which form the housing 22, in turn comprise a plurality of interconnected parts. The term "housing part" thus does not designate the smallest unit formed separately, but rather the housing units 22a and 22b which can be moved relative to each other.

Through the entire housing 22, a guide channel (not shown) extends along a longitudinal axis L of the housing 22, in which a screwdriver tool 16 (see. FIG. 2 ) of impact wrench 30 is guided. Such a screwdriver tool 16 may, for example, be a comparatively long screwdriver bit which should be long enough to extend from the output 40 or the coupling section 42 to which it is attached to the screw head of the screw to be introduced , Accordingly, a guide is provided within the magazine screw attachment 20 in the form of the guide channel.

The Magazinschraubvorsatz 20 has at its first housing part 22a, ie at the end facing away from the impact wrench 30 end, a receiving portion 24 for receiving a Magazingurtes (not shown) with screws. At the receiving portion 24, an adjusting mechanism 26 is additionally adapted to the screw length adjusted in the illustrated embodiment to adjust the screw length. In this regard, the adjustment mechanism 26 is shown in the figures in a position for use with screws having a maximum screw length, for example about 55 mm, which are adjusted by adjusting the mechanism 26 towards the impact wrench 30 can be reduced to the minimum screw length, for example, to about 25 mm.

The first housing part 22a can be displaced in the direction of the longitudinal axis L of the housing 22 relative to the second housing part 22b. As a result of this displacement, the screwdriver tool 16 accommodated within the housing 22 is brought with its screwdriver blade into engagement with a screw head, which is arranged on the receiving section 24 in alignment with the guide channel (indicated by the longitudinal axis L) of the screw to be introduced. As a result, a torque transmitted from the drive of the impact wrench 30 to the tightening tool 16 may be transmitted thereto for screwing the bolt.

On the second housing part 22b, a guide rail 28 is attached to guide the magazine seat. Furthermore, the second housing part 22b or the second housing unit 22b comprises the connecting portion 44 for releasably connecting the magazine screw attachment 20 with the impact wrench 30 and a handle 46 for more comfortable handling of the impact wrench system 10 according to the invention.

The connecting portion 44 is, as in FIGS FIGS. 1 and 2 to recognize, provided with a plurality of flutes 48 and acts in combination with a ring nut 50 as a clamping ring. For this purpose, the connecting portion 44 on its outer periphery on an external thread into which an internal thread of the ring nut 50 can engage.

Like in the FIG. 2 , A plan view of the inventive screwdriver system 10 of FIG. 1 , It can be seen better, an elastic return element 52 is provided between the housing parts 22a and 22b, which returns the two housing parts 22a and 22b after completion of the drive stroke when screwing back into their original position relative to each other. At the same time, the relative movement (return stroke) of the housing parts 22a and 22b moves the magazine belt relative to the magazine screw attachment 20, so that after a completed screwing operation, the following screw of the magazine belt is brought into a position aligned with the guide channel on the receiving section 24.

In the FIGS. 3 to 4b the impact wrench 30 is shown in a detached from the Magazinschraubvorsatz 20 representation, based on the FIGS. 4a and 4b the expression of the connecting means on the coupling section 42 can be seen. FIG. 4b shows the detail B of the FIG. 4a ,

The connecting means of the coupling portion 42 are formed in the illustrated embodiment by the recesses 54, the flats 56 and the connecting groove 58. The connecting groove 58 is engaged by one or more radial projections which protrude radially from the inside of the connecting portion 48 in the connected state of the Magazinschraubvorsatzes 20 with the impact wrench 30 and the connection of the Magazinschraubvorsatzes 20 with the impact wrench 30 axially secured in this way. The recesses 54 and the flats 56, however, in particular serve to prevent rotation of the magazine screw attachment 20 relative to the impact wrench 30. For this purpose, corresponding projections, which also protrude radially from the inner peripheral surface of the connecting portion 44, engage in the recesses or lie against the flats.

A central inner recess 60 on the end face of the output 40 and the coupling portion 42 of the impact wrench 30 serves to receive a screwdriver tool 16 and is in the illustrated embodiment of FIG. 4b formed with a cross section in the shape of an equilateral hexagon.

Claims (6)

A magazine screw attachment (20) for a powered impact wrench (30) for driving screws, in particular drywall screws, the magazine screw attachment (20) having a housing (22) with a guide channel extending along a longitudinal axis (L) of the housing (22) for guiding a Screwdriver tool (16) and with a connecting portion (44) which is adapted to produce a detachable connection with a driven impact wrench (30). Magazine screw attachment (20) according to claim 1,
wherein the magazine screw attachment (20) has at its end remote from the connecting portion (42) end a receiving portion (24) for receiving a magazine belt with screws. Magazine screw attachment (20) according to claim 2,
wherein the housing (22) comprises at least two housing parts (22a, 22b) which are axially retractive relative to each other in the direction of the longitudinal axis (L), wherein a drive unit is provided which during a movement stroke of the housing parts (22a, 22b) of the magazine screw attachment (20) is able to move relative to each other the magazine strap relative to the magazine screw attachment (20). Screwdriver system (10) comprising a driven impact wrench (30) and a magazine screw attachment (20) according to one of claims 1 to 3,
wherein the impact wrench (30) has a housing (32) with a striking mechanism received therein, characterized in that the impact wrench (30) on the output side a coupling portion (42) for releasable coupling with the connecting portion (44) of the Magazinschraubvorsatzes (20). Screwdriver system (10) according to claim 4,
characterized in that the coupling portion (42) comprises an output shaft of the impact wrench (30) surrounding sleeve-shaped housing having on its outer circumference connecting means (54, 56, 58) with corresponding connecting means on the connecting portion (44) of the Magazinschraubvorsatzes (20 ) to be able to interact with the impact wrench (30). Use of a magazine screw attachment (20) in conjunction with a powered impact wrench (30), wherein the magazine screw attachment (20) comprises a substantially two-part housing (22) with a guide channel extending along a longitudinal axis (L) of the housing (22) for guiding a screwdriver tool (16) and having a connecting portion (44) for making a detachable connection with the powered impact wrench (30).

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