DE2758446A1 - Socket wrench for fitting bleed screws of hydraulic brakes - has triangular cross-section with large radius rounded corners to reduce risk of slipping - Google Patents

Abstract

The socket, for fitting to a wrench for tightening bleed screws of automobile hydraulic brake systems is of traingular cross-section. The sides of the triangle run into rounded corners with a relatively large radius. The upper edges of the socket are chamfered at an angle of about 30 deg. and the chamfer decreases in the intended direction of rotation. The socket is less liable to slip when when tightening bleed screws and can also be used as part of an automatic machine which fits the bleed screws to the hydraulic brake system during manufacture.

Description

Such screw bits for tightening or loosening

For example, hexagon bolts or nuts can be found at Automatic screwdrivers on assembly lines use.

These commercially available known screw bits have a Hexagon socket or hexagon socket with straight lead-in chamfers. When driving up the screwdriver spindles of the automatic screwdriving machines equipped with these screw bits Malfunctions often occur on the hexagon of the screws or nuts. In case of misalignment of the wrench flats of the screw bit occurs opposite the flats of the hexagon often jamming so that d - nuts and bolts damaged, but not tightened or loosened. The result is material wear, rework and Disruption of the control process on the automatic screwdriver.

In the case of disc brakes manufactured on assembly lines, during the filling process the disc brakes with hydraulic fluid through the bleed screws Screw bits provided with a hexagon socket or hexagon socket from automatic screwdrivers released for venting. When jamming the screw bits on the hexagon of the These will damage the vent screws; also can hydraulic fluid leak into the open and oil the brake pads, as the outlet hole for the hydraulic fluid in the vent screw does not pass through that in the screw bit located seal is sealed.

The invention is based on the object of a screw insert Specify the type mentioned above, which allows a safe and damage-free loosening and tightening of hex nuts and bolts.

This object is achieved in that the Screw insert 1 has an inner triangle 2, the three key surfaces 3 of which on the insertion side have inclined, wedge-shaped lead-in chamfers 4, the surfaces of which are opposite increase for the respective direction of rotation of the screw bit 1.

The advantages achieved with the invention are in particular: that the proposed screw bit is a problem-free, secure and jam-free one Loosen and tighten hex nuts and bolts without damaging them same permitted.

Associated with this is a significantly reduced rework, a better utilization of assembly lines and reduced material wear. In particular are released when venting screws are loosened during the filling process of disc brakes with a hydraulic fluid by securely grasping the vent screw through the screw insert and the sealing of the outlet hole through the in the The seal located on the screw insert saves hydraulic fluid achieved and avoided oiling of the brake pads.

Further advantageous embodiments of the invention can be found in the subclaims.

An embodiment of the invention is shown in the drawing and is explained in more detail below.

The figures show: FIG. 1a a side view of a screw insert according to FIG of the invention ib a plan view of the introduction side of the screw bit it and FIG. 2 shows a schematic representation of the process of introducing a hexagon in the screw bit.

A screw bit 1 shown in Fig. La and b for loosening Hexagon bolts or nuts has an internal triangle 2, the three wrench flats 3 on the lead-in side inclined, wedge-shaped lead-in chamfers 4, the surfaces of which are opposite to the direction of rotation of the screw bit 1 (large arrow) increase.

The surfaces of the lead-in chamfers 4 form with the elongate Axis of symmetry 5 each have an angle y of about 300 and the delimiting edges 6.7 of the wedge-shaped lead-in chamfers 4 an angle 4 of 30 to 100, preferably 60. The apices 8 of the angles 8 of the lead-in chamfers 4 each lie in the planes of the adjacent wrench flats 3.

In Fig. 2, the process of introducing a hexagon is schematically 9 shown in a screw bit 1 for tightening a screw or a nut. When driving the screw bit 1 on the hexagon 9 slide three corners of the Hexagon 9 (small arrows) on the three inclined lead-in chamfers 4 opposite to the direction of rotation of the screw bit 1 (large arrow), as their surfaces are opposite increase towards the direction of rotation of the screw bit 1; the hexagon in question is 9 thus inserted safely and damage-free into the inner triangle 2. About the friction between the hexagon 9 and the screw bit 1 during this process to a minimum To reduce, the inclined lead-in chamfers 4 are advantageously polished and the boundary edges 6.7 rounded.

The three wrench surfaces 3 of the inner triangle 2 each assigned three surfaces 10 of the hexagon 9 are subject when using the proposed Screw insert 1 no greater load than when using a known one Screw insert.

With such a screw bit with a hexagon socket or hexagon socket the number of key surfaces is overdetermined; when the hexagon is centered, Due to the manufacturing tolerances, there are generally only three surfaces of the hexagon on the wrench flats of the hexagon socket or the hexagon socket.

The proposed screw insert 1 thus ensures a safe and easy loosening and tightening of hex nuts and bolts, without damaging them, and can be used on all automatic screwdrivers.

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Claims (5)

Claims K% i. Screw insert for tightening or loosening Hexagon screws or hexagon nuts, especially for vent screws with hydraulic brake systems, in that the screw bit is not indicated (1) has an inner triangle (2), the three key surfaces (3) of which on the insertion side have inclined, wedge-shaped lead-in chamfers (4), the surfaces of which are opposite increase for the respective direction of rotation of the screw bit (1). 2. Screw insert according to claim 1, characterized in that g e k e n n -z e i c h n e t that the surfaces of the lead-in chamfers (4) with the longitudinal axis of symmetry t5) each form an angle F of about 300. 3. Screw insert according to one of the preceding claims, characterized it is noted that the boundary edges (6,7) of the wedge-shaped lead-in chamfers (4) Form an angle of 30 to 100. 4. Screw bit according to claim 3, characterized in that g e k e n n -z e i c h n e t that the boundary edges (6,7) of the wedge-shaped lead-in chamfers (4) one Form an angle of 6 °. 5. Screw insert according to one of the preceding claims, characterized it is noted that the apices (8) of the angles of the lead-in chamfers (4) each lie in the planes of the adjacent wrench flats t3).