Robot arm

In order to guide a cable for a robot in a protective fashion while facilitating simple insertion of protected cables in a robot arm, in particular a robot arm bearing a hand arbor motor, having a cable guide channel extending substantially along the robot arm and having a sideward opening along its entire length.

This application claims Paris Convention priority of DE 198 17 607.4 filed
 Apr. 17, 1998 the complete disclosure of which is hereby incorporated by
 Reference.
 BACKGROUND OF THE INVENTION
 The invention concerns a robot arm, in particular a robot arm bearing a
 hand arbor motor.
 Robots have cables or cable bundles normally guided outside of the arm
 member. They can thereby be bothersome and are subject to external
 disruptions. On has therefore proposed guiding the cables within the arm
 member. This has the disadvantage that the cables have to be threaded
 through the arm or its housing and there are problems associated with
 length compensation.
 It is therefore the underlying purpose of the invention to configure a
 robot arm in such a fashion that the cables are disposed in a protected
 manner and can be guided into their protected position in a simple
 fashion.
 SUMMARY OF THE INVENTION
 This purpose is achieved in accordance with the invention with a robot arm
 of the above mentioned kind using a cable guide channel which extends
 substantially along the robot arm and which has a sideward opening along
 its entire length.
 A preferred embodiment provides that the sideward opening travels in an
 S-shaped fashion, wherein, in particular, the cable guide channel defines
 a flat cavity as a storage volume for the cable or cable bundles in the
 cable channel.
 Additional preferred embodiments of the invention provide that the cable
 guide channel travels from one longitudinal side of the robot arm to the
 other longitudinal side, wherein, in particular, the cable guide channel
 extends from a front region of a longitudinal side of the robot arm to a
 rear region of a longitudinal side of the robot arm. In this fashion, the
 cable channel provides optimum entrance and exit points with regard to
 feeding the cable from the base of the robot as well as with regard to
 passage of the individual cables to the individual motors, in particular
 the hand arbor motor of the corresponding robot arm but also the motor
 pivoting this robot arm.
 An additional preferred configuration of the invention provides that the
 width of the sideward opening is less than the corresponding transverse
 dimension of the cable guide channel. In this manner one prevents the
 cable from unintentionally slipping out of the cable guide channel, since
 the sideward opening is narrowed compared to the cross section of the
 cable channel to define confining undercut protrusions or shoulders at
 which the cable, in particular in the event that the cable channel is
 S-shaped, at least locally seats to thereby prevent an escape out of the
 cable guide channel.
 The invention generally effects a combined inward and outward cable guide
 having a storage region for excess cable lengths in the arm housing such
 that substantially standardized cables can be utilized. In addition,
 simple insertion and simple accessibility to the cable is effected, in
 particular e.g. in the event of exchange.
 Further advantages and features of the invention can be extracted from the
 claims and the following description in which an embodiment of the
 invention is described more closely with reference to the drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENT
 The robot arm 1 configured in accordance with the invention and shown in
 the figures can be pivoted about the horizontal axis A3 of a robot and
 bears hand arbor motors 2. A cable guide channel 4 is disposed on the
 upper side 3 of the robot arm within the housing thereof and extends from
 the front region facing away from the hand arbor motor 2 of one
 longitudinal side 6 of the robot arm 1 in an S-shaped fashion towards the
 rear, e.g. towards the hand arbor motors 2 and the other side 7 of the
 robot arm. The principal extension direction of the channel 4 runs
 substantially in the longitudinal direction of the robot arm 1. The cable
 guide channel 4 has a slotted opening 8 on its upper side which extends
 along the entire length of the cable guide channel 4. The opening 8 has
 widened ends 11, 9 at the ends of the cable guide channel 4 at the
 longitudinal sides 6, 7.
 Cables 13, 14 passing from the base of the robot to the hand arbor motors 2
 as well as to the motors 12 moving the robot arm 1 about the axis A3 can
 be easily and comfortably introduced sidewardly through the slot 8 into
 the cable guide channel. Since the transverse dimensions of the cable
 guide channel 4 are larger that those of the cables 13, 14 and/or of the
 overall height of these cables, the cable guide channel can define a
 storage region to accept and compensate for excess cable lengths. The
 cables nevertheless remain protected, seated in the cable guide channel 4.