Gear cutting – milling – or planing – Milling – Including means to infeed rotary cutter toward work
Reexamination Certificate
2001-09-07
2003-10-14
Wellington, A. L. (Department: 3722)
Gear cutting, milling, or planing
Milling
Including means to infeed rotary cutter toward work
C409S212000, C409S235000, C409S164000, C409S165000, C409S167000, C082S149000, C029S03300H
Reexamination Certificate
active
06632054
ABSTRACT:
TECHNICAL FIELD
The invention relates to a portal milling machine, i.e. a milling machine in a portal type of construction, according to the preamble of the independent patent claims.
PRIOR ART
Portal milling machines of the type mentioned at the beginning are generally known. They have a machine bed and a portal firmly connected to the machine bed. On the portal, which normally comprises two vertical columns firmly connected to the machine bed and a crossbeam connecting these columns to one another, a milling unit provided with a milling spindle or a tool spindle is arranged so as to be movable in a translatory manner in a first direction (Z) and a second direction (Y) transversely to the machine longitudinal axis (X) defined by the portal passage. Furthermore, portal milling machines of said type have a plane linear guide firmly connected to the machine bed. The linear guide is arranged essentially horizontally in the machine longitudinal direction (X), i.e. in the X-direction. It leads through the portal and serves to guide a slide which is movable in the X-direction through the portal and carries a work mounting device, typically in the form of a work table. Such portal milling machines are normally designed and arranged in such a way that the translatory direction of movement X runs essentially horizontally through the portal, the translatory direction of movement Z runs essentially vertically, and the translatory direction of movement Y runs essentially horizontally and at right angles to the X-direction.
Compared with single-column milling machines in a C-type of construction, which have a single, essentially vertical column, to which an extension arm carrying the milling unit is attached at the top and which is firmly connected to the machine bed at the bottom, the machine bed carrying a work table, portal milling machines have advantages with regard to the rigidity of the machine. The structure closed upon itself, consisting of the portal and the machine bed, can absorb greater forces, given the same dimensioning, than the structure, open on one side, of a single-column machine in a C-type of construction.
On the other hand, portal milling machines are less suitable for automated operation than single-column machines in a C-type of construction. On the one hand, in portal milling machines, the chip disposal is problematic, since the chips produced during the milling tend to remain sitting on the linear guide leading through the portal or on the chip cover guard of the linear guide. On the other hand, the accessibility to the tool processing point lying in the region of the portal and thus to the tool and to the workpiece is restricted by the portal.
DESCRIPTION OF THE INVENTION
The object of the invention is to specify a milling machine in a portal type of construction which can be readily automated and in particular ensures good accessibility to the tool processing point and permits good chip disposal.
The solution of the object is defined by the features of the independent patent claims. According to the invention, a portal milling machine has an elongated machine bed, the longitudinal direction of which defines an X-direction (also designated as machine longitudinal direction). Furthermore, the portal milling machine is provided with a portal which is arranged at right angles to the X-direction and has an elongated plan form, the longitudinal direction of which defines a Y-direction (also designated as portal longitudinal direction) (running at right angles to the X-direction). A milling unit is arranged on the portal so as to be movable in a translatory manner in a first direction and a second direction transversely to the X-direction, and a linear guide which leads through the portal in the X-direction and is intended for a slide carrying a work mounting device and movable in the X-direction is attached to the machine bed. In plan form, a part of the machine bed projects beyond the portal in the X-direction at least on one side, in which case this projecting part of the machine bed may also be the entire machine bed. According to the invention, the machine bed, with regard to the portal, is offset in the Y-direction toward one longitudinal end of the portal in such a way that, in the region of the angle enclosed between the projecting machine bed part and the portal, good accessibility to the working region of the machine in the region of the portal center is ensured from the other longitudinal end of the portal.
Due to the asymmetrical type of construction with regard to a vertical center plane running in the X-direction through the portal center, good accessibility to the tool processing point in the optimum working region of the machine, namely in the region of the portal center, is provided on the one hand. An operator can come from the side comparatively close up to the slide carrying the work mounting device or to the work processing point. This proves to be advantageous, e.g. when setting the machine for new machining operations, and helps to improve the ergonomics of the portal milling machine according to the invention. On the other hand, space is also created on the portal side remote from the machine bed, and this space may be utilized for the installation of the chip conveying device. On the whole, this provides for the possibility of automated operation of the portal milling machine.
The machine bed, with regard to the portal center, may be offset in the Y-direction toward the one longitudinal end of the portal by more than one sixth, preferably even by more than two sixths, of the clear width of the portal passage, in order to create sufficient space in the region of the other longitudinal end of the portal.
In the portal milling machine according to the invention having an asymmetrical type of construction, the portal is preferably arranged relative to the machine bed such that the structure formed from the portal and the machine bed has essentially a plan form like a two-legged right angle, one leg being formed by the machine bed plan extending in the X-direction and the other leg being formed by the portal plan extending in the Y-direction. In this case, the machine bed is arranged so as to be offset completely toward one longitudinal end of the portal and it projects in the X-direction beyond the portal merely on one portal side. As a result, an especially simple and compact structure of the machine is achieved overall.
According to a preferred embodiment of the invention, the linear guide is a plane linear guide arranged essentially horizontally (i.e. running in the horizontal direction), the guide plane of the linear guide, relative to the horizontal, being inclined by an angle transversely to the X-direction in such a way that chips produced during the milling fall down solely on account of the force of gravity from the linear guide or from a cover protecting the latter from the chips.
Throughout the present description and the claims, the expression “linear guide” (also designated as straight guide) refers to a bearing for guiding parts moving rectilinearly. A linear guide is designated as plane if it defines a guide plane extending in the guide longitudinal direction. In the case of a linear guide having an essentially flat, plane guide bed, the guide plane is determined by the guide bed surface. In this case, the guide bed surface need not be completely plane, but rather may be provided with passages, recesses, reinforcing ribs or similar structures which deviate in sections from the plane form of the guide bed surface. In a linear guide which comprises essentially a single, flat guideway (e.g. a flat guide or a dovetail guide), the guideway surface may be designated as guide plane of the linear guide. If a linear guide comprises two parallel rails or slideways, the plane determined by the two parallel rails or slideways may be designated as guide plane. If a linear guide is designed as a profiled rail guide having an essentially plane profile surface, to which a plurality of parallel guide rails are attached, this profile surface may be
Geiger Michael
Meier Peter
Mikron Comp-Tec AG
Ross Dana
Wellington A. L.
LandOfFree
Portal milling machine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Portal milling machine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Portal milling machine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3154188