Leveling and aligning device

Leveling and aligning device by which the distance at which a member is supported with respect to a base may be altered and firmly locked in the given adjustment without creating stresses in either the body of the member and the base or the device by itself. The leveling and aligning device allows continuation of the adjustment process even in case of inadvertent disengagement of components of the device.

TECHNICAL FIELD OF INVENTION

Generally, the invention relates to devices, which adjustably support a member with respect to a base anchored to the ground, or standing on the floor, a machine or another device. This type of adjustable support is used in situations requiring precise leveling or alignment of a supported member. Typical applications would include leveling and controlling the height of tables, machines and instruments, or adjusting the vertical alignment of objects like lampposts, masts, and vertical rods. Other typical applications include alignment of assemblies such as lasers, robotic systems, and winding and reeling assemblies for films and tapes. Typically, these devices feature easy accessibility for readjustment and semi-permanent, firm locking of the member in the given adjustment.

There are many ways of creating adjustable support of a member with respect to a base, patented or not. It is common knowledge that the member should be supported at three points to minimize stresses in the material, but the most commonly used procedures to make fine adjustments are shimming and using setscrews in close proximity of three holding screws. This violates the three-point support principle since the member is now actually supported not in three, but in six points.

There are devices providing adjustable support of a member, which satisfy the requirement of three-point support. One of them is disclosed in Paine, et al U.S. Pat. No. 3,669,393. The device provides reliable results, but is bulky, cannot be hidden in the body of the member, and is difficult to adjust. In many applications, the device cannot be used at all due to limited accessibility.

Another device is described in July 2004 edition of the Silicon Valley Automation catalog entitled “A Better Way to Level Your Hardware”. The PDF version of this catalog is included as an IDS. This device is known as the AFAB™ Alignment System. The devices is compact and easy to adjust. There is a significant drawback to this solution, however. If, during the adjustment process, a driving washer and an adjustment nipple lose connection, an assembler may be forced to perform a cumbersome recovery procedure. Another drawback of this solution is existence of strong stresses in the bodies of the leveling devices.

There are devices that address the problem of stresses in the body of the member and in the bodies of the leveling devices. Examples of such devices are Fernau, U.S. Pat. No. 843,641, Kotler, U.S. Pat. No. 2,327,050, Butler U.S. Pat. No. 2,403,338 and Burr, U.S. Pat. No. 6,520,459 B2. Although these devices reduce the stresses, all of them are related to leveling of equipment that is freestanding on floors, tabletops, or top surfaces of other machines. Additionally, none of these solutions provides a means for locking the member in the given adjustment in relationship to the base, relying exclusively on gravity.

There are other devices that theoretically release the stress in the bodies of the leveling devices and at the same time allow locking the required position of the member in relationship to the base. Such devices are disclosed by Attermeyer, U.S. Pat. No. 3,356,324, Paine, U.S. Pat. No. 3,669,393, Kober, U.S. Pat. No. 4,061,298, Cable, U.S. Pat. No. 4,108,407 and Kambara, U.S. Pat. No. 5,511,760. Practically components that are supposed to release the stress—a combination of a convex half-sphere inside a concave half-sphere of slightly larger diameter are causing even stronger stress. In theory, they have only one point of contact, which by definition generates high stress. In practice, the theoretical point of contact appears in non-existing areas of the spheres, in the areas occupied by openings for a locking screw. Instead, the components touch each other somewhere on the edge of the opening, generating a very strong stress.

BRIEF SUMMARY OF INVENTION

It is the principal object of the present invention to provide adjustable support of a member with respect to a base. The adjustable support can be easily adjusted, yet can be firmly locked in a given adjustment without stressing the material of either the base and the supported member or the adjustable support itself.

To achieve this object, the invention employs a threaded jacking sleeve, which can be threaded in and out of the body of the member. The bottom end of the jacking sleeve has a convex, spherical shape and mates with a concave, cone-shaped nest of a self-adjusting insert freely resting in a counterbore into the base surface. The insert further has a through hole in the center of the insert. Such solution gives so-called “line contact” distributing forces equally over a circle marked by the contact line between the ball and the cone. As the jacking sleeve is screwed in an out, the member rides down or up, resulting in precise setting of the required distance between the member and the base. The threaded jacking sleeve is turned by a driving washer with two protruding prongs on bottom. The driving washer has a through hole to accommodate a locking screw, and a coaxial counterbore to accommodate the head of the locking screw. The prongs engage a corresponding slot in the top of the jacking sleeve. When the jacking sleeve has been turned to achieve the desired distance between the member and the base, the adjustment can be securely locked in place by tightening a socket-head locking screw that is installed through the hole of the driving washer, the threaded jacking sleeve, the hole in the insert, and an opening in the base. The socket-head locking screw is threaded into a captive nut located in an oval groove in the base. The groove allows the captive nut to perform small x-y movements, but not to rotate. This solution effectively reduces stresses in the body of the member and in the adjustment device itself.

Although the phrase “with respect to a base” may suggest horizontal applications, devices employing the present invention can be used or placed at any angle, including up side down position, due to the ability of the device to securely lock an adjustment in place.

Another object of the present invention is to provide a solution for the problem described in the Background of the Invendon, and allow to continue the adjustment process, even if the assembler over rotates the jacking sleeve to the extent that the connection between the driving washer and the threaded jacking sleeve is lost.

To achieve this object, the ends of the prongs on the driving washer are slanted in such a way that during clockwise rotation, the prongs easily disengage from the threaded jacking sleeve's slot a fraction of a rotation earlier than they would if both sides of the prongs were of equal length and the prongs had flat ends. When the driving washer is turned counterclockwise, the prongs engage with the threaded jacking sleeve's slot wall, allowing the threaded jacking sleeve to be turned into the body of the member. To enhance effectiveness of this feature another pair of slants could be cut on corresponding edges of the threaded jacking sleeve's slot.

Another object of the present invention is to enable the leveling device to maintain a given adjustment when subjected to vibrations.

To achieve this object, an optional spring washer is placed between the bottom of a counterbore of the driving washer and the head of the locking screw.

As shown in the accompanying drawingsFIG. 1,FIG. 2, andFIG. 3the preferred embodiment of the present invention that we will refer to as “Leveling and Aligning Device” comprises base15having round opening23, and a shallow counterbore24for reception of insert25on the top. The bottom of base15also has an oval groove22for reception of captive nut20and grooved counterbore21for reception of washer16and internal retaining ring18.FIG. 3is a cross sectional view taken along line3-3inFIG. 2and shows how the oval groove22prevents captive nut20from rotation. Grooved counterbore21, washer16and internal retaining ring18are an example of providing a means for loosely securing captive nut20in oval groove22, and can be replaced with any means providing the same function.

Means are provided for supported member7to be variably positioned with respect to base15. Member7is adjusted with threaded jacking sleeve13, which has slot27that engages with two prongs9of driving washer3. The adjustment is achieved when driving washer3, located inside of counterbore31of member7, is turned, employing prongs9to cause jacking sleeve13to turn within member7, thus adjusting position of member7up or down with respect to base15.

Optional spring washer6is installed loosely around locking screw19, and is used for applications where the entire mechanical device is subjected to vibrations or heavy mechanical impacts. Spring washer6is positioned between the bottom of counterbore4and head2of locking screw19.

Bottoms12of prongs9are slanted or have a ramp surface in such way that, during clockwise rotation of driving washer3, the attacking sides30of prongs9are shorter than their opposite sides8. Such design allows prongs9of driving washer3to disengage from the threaded jacking sleeve's slot27a fraction of a rotation earlier they would if the ends of the two prongs9were flat and parallel to top of jacking sleeve13. The disengagement will occur providing there is sufficient gap5between the bottom of counterbore4of driving washer3or spring washer6and head2of screw19. When the driving washer3is turned counterclockwise the sharp edges11of long sides8of prongs9engage with sharp edges10of slot27of threaded jacking sleeve13allowing threaded jacking sleeve13to be turned back into threaded opening29of the body of member7. To enhance effectiveness of this feature another pair of slants or ramp surfaces28can be cut on corresponding edges of slot27of the threaded jacking sleeve13.

The bottom end of threaded jacking sleeve13presents a convex, spherically curved surface14concentric with a through hole25a, which rests in a concave, cone-shaped nest26of the self-adjusting insert25.

Driving washer3is rotated with a special tool not shown on the drawing, which has two prongs that engage slit32in the body of driving washer3.

A locking screw19and a captive nut20are provided for locking a given adjustment of member7with respect to base15with an Allen wrench inserted into an opening1of the locking screw19. The locking screw19which is inserted into a through opening31aof the driving washer3, the jacking sleeve13, the through hole25aof the insert25and the opening23in the base15, engages with the captive nut20located in oval groove22of base15. The self-adjusting captive nut20is protected with washer16and held in place by internal retaining ring18, which is snapped into groove17of counterbore21.