Gear cutting – milling – or planing – Milling – Cutter spindle or spindle support
Reexamination Certificate
2000-07-31
2002-10-01
Howell, Daniel W. (Department: 3722)
Gear cutting, milling, or planing
Milling
Cutter spindle or spindle support
C279S002190, C279S002220, C279S067000, C279S155000, C403S324000, C409S234000
Reexamination Certificate
active
06457920
ABSTRACT:
FIELD OF THE INVENTION
1. Background of the Invention
The present invention relates to a clamping system for detachably connecting two parts, such as is used for coupling a workpiece or tool carrier, for example in the form of a tool base holder, to a manipulator unit such as a spindle of a machine tool, or for coupling tool system modules to one another.
2. Discussion of the Background
In such clamping systems the objective is to clamp the parts to be connected reliably and firmly against one another, thus ensuring exact positional fixation of the parts to be connected relative to each other via close-fitting engagement between the faces of a hollow shank of the one part and of a holding portion of the other part. The tightening or clamping of the two parts to be connected against one another is achieved by the fact that the hollow shank is pulled into the holding portion against an undercut clamping shoulder formed in the hollow shank during application of clamping members of a clamping device. In the process a pressing force is developed between plane faces of the parts to be connected, so that the two parts clamped against one another are provided with exact axial and also radial positional fixation by the firm connection between the close-fitting faces.
In more recent times there has been increasing acceptance of the hollow-shank clamping system, in which the hollow shank has either cylindrical or tapered structure. In the joined-together condition of the two parts to be connected to each other, the clamping members used for clamping the parts against one another ensure not only that an adequate axial pressing force is developed but also that the hollow shank experiences a certain radial flaring, whereby the accuracy of fit between hollow shank and holding portion is additionally improved.
In conventional clamping systems according to the principle described hereinabove, the assembly and disassembly of the clamping device in the holding portion provided therefor represents a special problem,. however, since the clamping system must also absorb the reactions to the clamping force in addition to ensuring exact axial and radial positional fixation of the two parts to be connected.
From German Patent Application DE A 4220873, there is known a clamping system for detachably connecting two parts, which preferably are rotationally symmetric, of which one part has a preferably cylindrical or tapered hollow shank and the other part has a corresponding holding portion for holding the hollow shank in accurately fitting relationship. There is provided a clamping device which is disposed concentrically in the holding portion and which, in the joined-together condition of the two parts, extends into the hollow shank of the one part and is provided with at least two clamping members which can move in opposite directions as well as with an actuating device for driving the clamping members, by means of which device the clamping members can be synchronously moved into and out of engagement with an undercut clamping shoulder of the hollow shank, whereby a pressing force is generated between plane faces of the two parts to be connected.
This clamping system is based on the principle described hereinabove of clamping two parts to be connected by a clamping device having clamping members. In this clamping system the problem cited hereinabove is solved by exact positional fixation of the parts to be connected, in that a support member decoupled from the clamping members as regards assembly is fixed interlockingly in the holding portion. The positionally fixed support member brings about bracing of the clamping members and thus indirectly absorbs the reactions to the clamping force. The indirect absorption of the reaction via the support member as well as the fastening and positional fixation thereof can be achieved, however, only by additional fixing and fastening elements. Furthermore, special assembly attachments are generally necessary.
In another known clamping system, as is described, for example, in German Patent DE C2 3807140, a plurality of loosely disposed or at least not distinctly fixed clamping elements must be nested interlockingly in the holding portion. In this case an additional support member is indeed unnecessary, but the direct nesting of the clamping elements is associated with considerable assembly complexity, since the individually disposed clamping elements are not distinctly fixed in assembly position. Accordingly, the clamping elements must be moved into a special assembly/disassembly position during assembly/disassembly. Additional components and assembly attachments are necessary for this purpose also.
From German Utility Model DE U1 29518660 there is known a clamping system according to the preamble of the new claim
1
.
A threaded sleeve, a clamping ring and a plurality of segmented bracing elements are necessary for fixation of the clamping-element halves in the tool spindle. The head parts of the clamping-element halves are therefore braced against the undercut clamping shoulder of the tool mandrel via a “mechanism” formed by the clamping ring and the bracing elements.
The object of the present invention is therefore to provide a clamping system for two parts to be connected, for example a tool system module and a machine tool spindle, which clamping system on the one hand performs adequately with a minimum of components and on the other hand permits simple, reliable and dimensionally stable coupling of the two parts to be connected without the need for additional assembly or fastening attachments.
This object is achieved by a clamping system with the features of claim
1
.
According to the invention, the clamping elements are each provided in a region between head and foot portions with a retaining portion, which can be brought into engagement with an undercut recess of the holding portion.
Just as heretofore, therefore, the clamping members are still designed as head portions of elongated clamping elements disposed substantially parallel to the longitudinal or rotational axis of the holding portion. The clamping elements are constituents of the clamping device. The foot portions of the clamping elements are inventively connected to one another such that the clamping device has substantially the form of a V-shaped or U-shaped split chuck or clamping fork.
These clamping elements can be connected to one another movably, interlockingly and frictionally or in one piece. By means of an actuating device the clamping members can be made to move in opposite directions, or in other words to move toward or apart from one another. The inventive clamping system with such a predetermined arrangement of clamping elements relative to one another therefore obviates the support members which in conventional clamping systems are necessary for the clamping elements or clamping members.
This arrangement of the clamping elements also permits, without additional fixing components, distinct axial as well as radial fixation of the clamping members relative to one another in both the clamped position and detached position of the clamping system. The inventive clamping system is therefore characterized by simple and compact structure, which also permits reliable and dimensionally stable clamping of the parts to be connected without a plurality of loose components. In addition, the connection of the clamping elements in the manner described hereinabove creates a clamping device which, since it does not comprise any loose parts, can be fixed in the holding portion without great mechanical complexity.
Since, moreover, a minimum of movable parts is present in the inventive clamping system, only little friction is developed during movement thereof. In this way a relatively large clamping force is achieved between the two parts to be connected.
Further advantageous embodiments of the inventive clamping system are subject matter of the dependent claims.
The clamping elements are preferably designed as the arms of a U-shaped clamping fork of one-piece construction. In such a configuration the c
Howell Daniel W.
Joerg Guehring
LandOfFree
Clamping system for detachably assembling two pieces does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Clamping system for detachably assembling two pieces, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Clamping system for detachably assembling two pieces will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2929295