The present invention relates to a brake lathe station, and more particularly to a station that combines a post supported vehicle lift with an integrated on-vehicle disk brake lathe positioner.
There have been a variety of brake lathes developed to reduce or eliminate the lateral run-out of brake disks that can develop when the brakes are in service. There are bench lathes where the brake disk must be removed from the vehicle, caliper lathes that attach to the brake calipers, and on-vehicle lathes where the lathe attaches to a hub associated with the disk to be resurfaced. These lathes, and in particular the on-vehicle lathes, are discussed in U.S. Pat. Nos. 5,974,878; 6,050,160; and 6,101,911.
Classically, the on-vehicle brake lathes are employed in combination with a vehicle lift employing one or more support posts, such as are currently available from a variety of suppliers. These lifts allow the vehicle to be suspended so that its wheels are free to rotate. The wheels are removed and the on-vehicle lathe is attached to a hub from which the wheel has been removed. The hub is affixed with respect to an associated brake disk, and the two share a common axis of rotation. After the on-vehicle lathe is attached to the hub, it is aligned with the hub and the disk such that an axis of rotation of the lathe is substantially coincident with the axis of rotation of the hub and disk. Details of the typical operation of the lathe are further described in the above referenced patents.
The attachment of the on-vehicle lathe with the hub is manually done by the operator who uses a positioning dolly to manually adjust the relative positions of the on-vehicle lathe with respect to the hub. While this procedure works, it requires that the floor space be free from obstructions so that the dolly can be rolled across the floor without encountering obstructions, and also introduces the dolly into a limited space which may hinder other operations. The use of a dolly also requires the operator to move the dolly across the floor and, at the same time, roughly align the on-vehicle lathe with the hub. This can be difficult and requires appreciable force to be applied by the user when the floor is irregular, and also can result in limited control of the response of the dolly to the user""s actions.
The problem of locating a tool at or near its in use position by remotely mounting the tool with respect to a stationary post via a series of interconnecting pivoting arms has been classically done in a variety of work stations. Such work stations are frequently used in maintenance employed for repairing vehicles. Similar support and transport systems are also used in dental offices to allow manipulation of instruments such as X-ray cameras. An alternative to using a stationary post for support has been to use a track mounted above the work area having a carriage mounted thereon, which in turn supports and transports a tool about a work space. The above described devices are well suited to allow the tool to be supported as it is brought into position, so that the operator can position the tool accurately without having to also support its weight. Frequently, when rail-guided carriages are used in automotive applications, they are employed in combination with a chain fall suspended therefrom to accommodate changes in the height of the tool, which is suspended in turn from the chain fall.
While these positioning devices have been in use for years, such have not been employed in combination with a lift and an on-vehicle brake lathe, which introduces certain special needs. Thus, there is a need for an on-vehicle lathe station for refinishing disk brakes that eliminates the need for a positioning dolly.
It is an object of the invention to provide an on-vehicle brake lathe positioning and stabilizing mechanism that does not require a dolly.
It is another object of the invention to provide a on-vehicle brake lathe positioning and stabilizing mechanism which attaches to a lift.
It is still a further object of the invention to provide a removable on-vehicle brake lathe positioning and stabilizing mechanism from which the lathe can be removed for storage or use at a location remote to the lift.
A further object of the invention is to provide a positioning and stabilizing mechanism for an on-vehicle brake lathe which reduces the transmission of vibrations to the on-vehicle brake lathe while countering torque generated by the on-vehicle brake lathe as it turns the hub of a vehicle.
It is another object of the invention to provide a dual coupling for an on-vehicle brake lathe which is configured such that the lathe can be simultaneously attachable to a dolly and to a positioning and stabilizing mechanism, thereby facilitating transfer of the on-vehicle lathe between the dolly and the positioning and stabilizing mechanism.
The present invention is an improved brake lathe station which uses an on-vehicle brake lathe. Examples of such on vehicle brake lathes are described in U.S. Pat. Nos. 5,974,878; 6,050,160; and 6,101,911. The brake lathe station has a lift with one or more support posts, which in turn have vehicle undercarriage supports that are pivotally connected to the support post and raisable and lowerable thereon. Such lifts are commercially available, and frequently employ two support posts.
The improvement resides in providing a means for positioning the on-vehicle brake lathe with respect to a horizontal plane, hereinafter referred to as xe2x80x9chorizontal positioning meansxe2x80x9d. The horizontal positioning means is attached with respect to the one or more support posts of the lift to assist a user in positioning the lathe with respect to a wheel hub for mounting the lathe thereon. The hub has an associated brake disk, and the hub and disk share a common hub axis. To mount the lathe on the hub, the lathe must be positioned such that a lathe rotation axis of the lathe is roughly in line with the hub axis. After mounting, the lathe rotation axis and the hub axis can be effectively aligned by an alignment mechanism which can be an integral part of the lathe, as further discussed in the above referenced patents.
The horizontal positioning means is configured to support the lathe while allowing it to be moved with respect to a horizontal plane to positions in close proximity to each of the hubs. This allows the operator to readily position the on-vehicle lathe with respect to the hubs of the vehicle.
The improved brake lathe station also has a coupling for attaching the on-vehicle brake lathe with respect to the horizontal positioning means. Preferably, this coupling also is designed to prevent rotation of the on-vehicle brake lathe with respect to the hub to which the on-vehicle lathe is mounted. It is also preferred for the coupling to be lockably adjustable to allow the lathe to be rotated about the lathe rotation axis through a wide range of orientations to allow the lathe access to the brake disk and avoid obstruction with other elements of the brake system such as dust shields. Also, it is preferred for the coupling to accommodate tilting. The range of tilt should be such as to allow the lathe rotation axis to be tilted up to about 15 degrees from horizontal. Providing such a range of tilt permits the lathe rotation axis to be aligned with the hub when the hub becomes canted by the suspension of the vehicle when the vehicle is raised off its wheels.
In one preferred embodiment, the horizontal positioning means has a track for transporting the on-vehicle brake lathe. A lathe support carriage slidably engages the track and has a lathe brace attached thereto. The brace in turn is attached to the on-vehicle lathe by the coupling. In one preferred embodiment employing a track, a substantially vertical wand is employed as the brace. It is further preferred for the track to circumscribe the one or more support posts of the lift. When the lift employs multiple support posts, it is preferred for the track to attach to the support posts of the lift.
To facilitate the use of the lathe station with various sizes of vehicles and allow fine adjustment of the lathe position with respect to the hubs, the on-vehicle lathe is preferably mounted with respect to the track so as to provide motion substantially normal to the track. One preferred means for providing motion normal to the track is by having the brace slidably engage the carriage so as to provide a motion in a direction substantially normal to the track.
Another preferred embodiment has horizontal positioning means having at least two lathe supporting arms, which are pivotably attached to each other to allow them to be rotated so as to provide pivotal motion in a substantially horizontal plane. In this embodiment, one of the arms pivots about a point which is fixed with respect to each of the at least one support posts. The other arm is attached to a brace which supports the on-vehicle lathe and which is attached thereto by the coupling. In a further preferred embodiment, the fixed point of the lathe supporting arms resides over one of the support posts. This embodiment is well suited to lifts which employ a single support post.
Another preferred embodiment, which employs a lift having a pair of support posts connected by a stabilizing bar, employs horizontal positioning means having a single lathe supporting arm, which is pivotably mounted to an arm carriage. The arm carriage in turn traverses the stabilizing bar to provide an additional degree of freedom in positioning the lathe. Again, this lathe supporting arm is attached to a lathe brace which in turn is attached to the on-vehicle brake lathe by the coupling.
When one or more lathe supporting arms are employed, it should be noted that a means for rotation of the on-vehicle lathe with respect to the arms about a vertical axis is necessary to allow the lathe to be properly directed with respect to the hub. There are multiple ways in which such rotational freedom can be supplied. For example, the lathe brace can be pivotably mounted to the lathe support arm or the rotational freedom can be provided via the coupling.
The on-vehicle brake lathe must also be positioned with respect to the hub in a vertical plane. The vertical position of the on-vehicle lathe with respect to the hub can be adjusted by repositioning the undercarriage supports with respect to the support posts on which they are mounted. While this approach simplifies the structure of the brake lathe station, adjusting the elevation of the undercarriage supports with precision can be difficult. Thus, it is preferred to provide means for positioning the on-vehicle lathe with respect to a vertical plane independently of the elevation of the vehicle, hereinafter referred to as xe2x80x9cvertical positioning meansxe2x80x9d.
When the lathe brace is a wand, the vertical positioning means can be provided by making the wand extendable. The extendable wand can be driven by a variety of devices such as a rack and pinion, a linear actuator, or a jack screw.
In another embodiment, the lathe brace is provided by a pair of lathe height adjusting arms which are disposed between the horizontal positioning means and the on-vehicle brake lathe. The lathe height adjusting arms are configured to pivot about a substantially horizontal axis and, in combination with means for varying the included angle of the lathe height adjusting arms, can provide the vertical positioning means. It is further preferred for the lathe height adjusting arms to be pivotably mounted about a horizontal axis with respect to the horizontal positioning means. This allows the lathe height adjusting arms to provide adjustment of the position of the lathe toward and away from the hub.
It is preferred for the on-vehicle brake lathe to be mounted with respect to the horizontal positioning means such that it can be floatably coupled with respect thereto when the lathe is mounted on the hub. Since the lathe is supported by the hub when it is mounted thereto, it does not require support from the horizontal positioning means until the lathe is to be removed.
Floating the lathe with respect to the horizontal positioning means after the lathe has been mounted to the hub serves to damp vibrations that might otherwise be transmitted to the lathe through the horizontal positioning means and which might adversely affect the machining of the brake disk. When the coupling is designed to prevent rotation of the lathe, the ability to float the lathe should be designed to maintain the ability of the coupling to prevent rotation while the lathe is floated.
When vertical positioning means are employed for adjusting the height of the lathe, floatable coupling of the lathe with respect to the horizontal positioning means can be provided in a variety of ways. When, for example, a rack and pinion mechanism is employed as part of the vertical positioning means, separating the pinion from the rack can serve to decouple these elements and provide a floatable coupling of the lathe with respect to the horizontal positioning means.
In all cases, it is preferred that the coupling that attaches the on-vehicle brake lathe to the lathe brace be a detachable coupling. It is also preferred that a supplemental coupling be provided, to which a dolly can be attached to support and transport the on-vehicle brake lathe. The supplemental coupling allows the lathe to be mounted onto the dolly while still being supported by the horizontal positioning means. The lathe can thus be readily mounted to the dolly, detached from the horizontal positioning means, and removed for use at another station while the vehicle remains on the lift or when it is desired to make the lift of the brake lathe station available to perform other functions.