DE3320239A1 - Screwdriving attachment for hand-held drilling machines - Google Patents

Abstract

A screwdriving attachment for hand-held drilling machines which are usable in particular in right-hand and left-hand rotation is to be improved such that the limit torque desired in each case and the screwdriving attachment can be set in a continuously adjustable manner with a minimum degree of complexity. For this purpose, it is proposed to arrange, between a front pressure disc which surrounds the drive shaft concentrically, is supported by means of sliding elements opposite a carrier plate fixedly connected to the drive shaft and is mounted in the casing so as to be secured against rotation, and a rear spring plate which is guided in the casing so as to be secured against rotation and longitudinally displaceable and is likewise situated concentrically with the drive shaft, a compression spring which is continuously adjustable within its spring range by axial displacement of the spring plate by means of an adjusting device accessible from outside (Fig. 1). <IMAGE>

Description

Patent - Verwaltungs - GmbH Theodor-Stern-Hai 1, 6000 Frankfurt. ,

E5 83 / a Frankfurt, May 31, 1983

Dr.ülf / Sch

Screw attachment for hand drills

The invention relates to a screw kit for means Electric motor-driven hand drills, preferably clockwise and counterclockwise, for use as screwdrivers, whose drive shaft can be combined with the drill spindle of the hand drill or .. is drivable.

The invention is based on the object of a screw attachment for to create a hand drill that can be operated in clockwise and counter-clockwise rotation, which is simple in construction and is continuously variable Setting the required limit torque in each case allows.

To solve this problem, the invention provides between a concentrically surrounding the drive shaft, opposite a drive plate firmly connected to the drive shaft via sliding elements supported and secured against rotation in the housing at the front Thrust washer and a non-rotatable and longitudinally displaceable in the housing and also concentric to the drive shaft lying rear spring plate one by axial displacement of the spring plate by means of an adjustment device accessible from the outside to arrange continuously adjustable compression spring within the scope of their spring travel.

The axial displacement has proven to be particularly advantageous of the spring plate and thus the compression or recompression to make the spring by means of a worm wheel, which can be set in rotation from the outside by a worm and on its The spring plate facing the front side is provided with cams, which are attached to the rear side of the spring plate cor-

Respqndierende cams or approaches act in such a way that when. When the raised points of the cams of the spring plates run against each other, they are pressed forwards against the force of the spring will and vice versa.

The invention is illustrated below with reference to the drawing an embodiment illustrated schematically, explained.

They show: FIG. 1 a longitudinal section through the screw attachment, ■ - " ^r ·

Fig. 2 is a view along the section A-B through Fig. 1,

3 shows a longitudinal section through the arcfci-eiriEBofirmmachine transmission with integrated coupling.

üie from Fig. 1 can be seen, .enthät the drive shaft 1 a Recording 2 in the form of a large threaded hole for the not shown Threaded end of the spindle of the drilling machine. The drive shaft 1 is rotatably mounted on the drive side by means of a roller bearing 3 in the housing and stands on the output side via a further roller bearing 5 with the liierkzeugauf would take 6 in l / connection, which in turn is arranged rotatably in the housing with the aid of a roller bearing 7.

On the output-side end face 9 of the drive shaft obtained by producing a pin with a tapered diameter a driver disk 10 pressed by means of an annular disk 11, which is secured against axial displacement by a locking ring 12 is secured. The drive plate 1G is firmly connected to the drive shaft 1 through a two-sided hole, for example.

The drive plate has a number of bores on its circumference 13 for receiving a corresponding number of balls 14. For example, between three and twelve balls may be provided. The balls 14 are supported on the one hand at matching recesses 15 in the tool holder 6, on the other hand on the front side of a thrust washer 16. The thrust washer 16 is guided in the housing 4 so that it cannot rotate and encloses it the drive shaft 1 is concentric.

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Through the balls 14 is the relative movement between the rotating Drive plate 10 and the fixed pressure plate 16 ensured with the least possible friction. On the inner surface of the thrust washer 16 is one end of a Compression spring 17, the other end of which is supported on a spring plate, which is axially displaceable, but non-rotatable in the housing 4 is arranged. The spring plate points to the spring facing away (rear) end face cam-shaped lugs 19 which correspond to the adjusting cams attached to the worm wheel 20 (see FIG. 2 in this regard).

The worm wheel 20, which. '"motörseitig supported on an intermediate wall 22 of the housing, a worm 23 associated with which by means of a handle (turning handle) 24 (Figure 2) operable from the outside is _r which a setting scale is assigned to 25 .. Upon actuation de.r screw in the sense of When the compression spring 17 is compressed (tensioning the spring), the adjusting cams 21 of the worm wheel 20 run against the corresponding cams 19 of the spring plate 1B in accordance with the actuation path of the worm 23 and press the latter forward in the direction of the arrow the thrust washer 16, which in turn would take the pressure or the pressing force on the drive plate 10 and the hills 14 to the LJerkzeugauf transfers 6. in order for this contact pressure sets the corresponding transmittable maximum torque determined If this torque is exceeded., the Uerkzeugaufnähme 6 stops and the drive shaft 1 rotates via the roller bearing 5 relative to the lüerkzeug recording, the balls 13 being pressed out of the recesses 15 against the force of the compression spring 17 (audible process).

_. _ or when turning them

The rotation of the screw 23 in the opposite direction / becomes the compression spring 17 relaxed and accordingly the limit torque less.

The maximum l / shift position of the spring and its starting position (Shift position "zero") can be limited by stop if necessary be defined.

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In this way, the desired limit torque can be achieved Drill in the direction of the longitudinal axis of the spring through the maximum and minimum extension of the corresponding [\ iocken 19,21 defined limits can be set continuously.

The sliding point between the drive plate 1o and the printer ;; disk 16 can also be realized by an axial bearing.
Furthermore, the adjustment of the spring plate 18 in the axial direction can also be done by an externally actuated eccentric lever
take place. Alternatively, there is also the possibility of providing a ring gear to adjust the spring plate 18, which with
a counter gear mounted rotatably on the drive shaft 1 of the screw attachment is in engagement, which has adjusting claws, which with the cam-like lugs on the spring plate
correspond.

The screw kit according to the invention can also be more integrative Be part of the gearbox of the drill, with the drive plate is designed as a gear.

Fig. 3 shows the integrated in the transmission of a hand drill Coupling.

The drive plate is in this case designed as a drive gear 10 'arranged on the drive shaft 1 of the clutch, which with
a gear 27 mounted on the countershaft 26 is in mesh. The countershaft 26 is set in rotation via a gear that is connected to the pinion 29 of the motor shaft 3D
combs. The clutch pressure plate 16 is supported on spherically rounded cylinder bolts 31, in which axial through- ^{holes are inserted in the drive gear 1D 1.}
the Ltlerkzeugaufnähme 6 coupled, which for this purpose with
Dome-shaped recesses 15 'is provided.

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The drive shaft 1 is in an eye 32 of the transmission housing 4 ' mounted rotatably by means of a roller bearing 33.

When the set limit torque is reached, the tool holder 6 stops and the drive gear 10 ' engages during its rotary movement, overcoming the restoring force the compression spring 17 from the recesses.-15 'of the Iderkzeugaufnahme the end.

BATH ORIGINAL

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Claims (7)

* .. * "L. * i fc.feVn * t * i.'a · - ·." Patent - Verwaltungs - GmbH 3320239 Theodor-Stern-Kai 1, 6DDD Frankfurt ES 83 / -S Frankfurt, May 31, 1983 ■ Dr.wT / Sch Claims .j screw attachment for driven by an electric motor, preferably Hand drills that can be operated in clockwise and anticlockwise rotation for their use as screwdrivers, the drive shaft of which is üjje'r the drill spindle of the hand drill is> .antT_eib bar, thereby characterized in that between a concentrically surrounding the drive shaft (1), opposite one fixed to the drive shaft connected drive plate (1D) via sliding elements Supported and twist-proof in the housing attached front Thrust washer (16) and one anti-twist and longitudinally displaceable: The rear spring plate (18) guided in the housing and also lying concentrically to the drive shaft is a through axial displacement of the spring plate by means of an externally accessible adjustment device that is continuously adjustable within the scope of its spring travel Compression spring (17) is arranged. 2. Screw attachment according to claim 1, characterized in that the spring plate (18) on its end face facing away from the spring is provided with cam-like lugs (19), which on the end face of a rotatable on the drive shaft (1) supported on its rear surface on the housing and rotated by means of an externally actuated worm (23) displaceable worm wheel (20) attached corresponding adjusting claws (21) are assigned. 3. Screw attachment according to claims 1 and Z, characterized in that the driver plate (1D) is positively and non-positively connected to the drive shaft (1) via driver surfaces and is provided in the circumferential direction with bores for receiving mounds (14) on which "the twist-proof in - ^z - COPY The housing-guided thrust washer (16), and the output side on one with matching recesses Cf5 ") Covenant of the acceptance of the tool ~~ (6). 4. screw attachment according to claims 1 to 2, characterized in that that the sliding point between the drive plate (TO- ') and thrust washer (16) is realized by a thrust bearing. .. .. 5. screw attachment according to claims 1, 3 and 4, characterized in that that the creation of the spring plate (1Θ) in Axial direction takes place by means of an eccentric lever that can be actuated from the outside. 6. screw attachment according to claims 1, 3 and 4, characterized in that that . ■ To adjust the spring plate (18) a van externally actuatable plate gear is provided, which -im Engagement with a counter gear mounted rotatably on the drive shaft (1) of the screw-byor set s'teht ', ■' ". ' , which is provided with adjusting cams that correspond to the neck-like extensions on the spring plate. 7. screw attachment according to claims 1, 2, 6 and 7, characterized in that that it is housed in the gear housing of the drill, with the drive plate as having a a drive gear 10 'that is in engagement is formed on a gear shaft 25 of the drill transmission, the one used in axiBl ^ n bores, spherical on both sides rounded «. contains cylindrical spacers 30, on which on the one hand the pressure disk 16 and on the other hand the Lüerkzeugaufnahme 6 is supported, which for this purpose with dome-shaped Recesses 15 'is provided for the engagement of the spacer elements.