Geometrical instruments – Distance measuring – By flexible tape
Reexamination Certificate
1999-05-05
2001-05-01
Bennett, G. Bradley (Department: 2859)
Geometrical instruments
Distance measuring
By flexible tape
C033SDIG002
Reexamination Certificate
active
06223446
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to level and grade measuring devices and more particularly to a simple and easy-to-use level and grade measuring device employing tape measures, bubble indicators and a light beam.
2. Description of Related Art
Numerous devices have been developed to assist in the measurement and checking of site contours and elevations. The elevations of landmarks are, in the majority of cases, surveyed by means of a linear measuring instrument which requires the presence of two operators using complex and sensitive equipment. Such an operation is tedious, long and expensive. Moreover, the surveying done by two operators is conducted at the beginning of a project to determine the site topography. The survey instruments are not practical for quickly and easily checking grade levels and contours. For quick on-site use, the device should be small, self-contained, portable and easy-to-use.
Other devices have been developed that allow for use by a single operator. For instance, in U.S. Pat. No. 5,551,159 to Mooty, a laser level apparatus is disclosed for use by a single operator. The operator uses a grade pole having a movable laser level receiver. The receiver detects a laser signal from a mounted laser transmitter usually fixed on a tripod some distance from the device. An indicator electronically coupled to the receiver is used to provide the operator a response when the laser beam is detected. Although fairly accurate, this apparatus is complex, heavy and expensive. It requires the operator to first properly level the transmitter on the tripod, align the laser beam and then reposition the receiver to properly align the receiver to the laser beam.
U.S. Pat. No. 4,274,203 to Vasile also discloses a complex and bulky grade measuring device. The device is generally mounted on a tripod and uses two tape measures along with a conventional sighting device for aligning to a known point. One of the tape measures is used to measure the horizontal distance to the point and the other is used to measure the vertical height of the device above the ground. Bubble levels are mounted on the sighting mechanism to determine if it is level. The device also uses complex electronics to provide a digital display of the distance that the tape measures are extended. Again, the device is too bulky and complicated for quick and easy grade checking.
U.S. Pat. No. 4,459,758 to Halle also discloses a device for measuring and checking site contours and elevations. The patent discloses a rotatable table mounted on a tripod. The table holds a device which transmits a laser beam parallel to the table. The device also provides a measuring tape that can be extended parallel to the laser beam. When the table and tripod elevation is fixed, the laser beam illuminates an aimed point for the operator and the distance to the aimed point can be measured with the tape. Because of the tripod and table arrangement, this device is not capable of quick and easy measurements. In addition, the device does not provide a means for measuring the elevation of the table.
U.S. Pat. No. 5,784,792 to Smith discloses a hand held tool for use in checking the level or grade of ground surface at a construction area. The cylindrical device emits a laser beam from one end which is in axial alignment with the device housing. The housing contains a bubble level to ensure that the device is held level to the ground.
In use, the operator holds the device alongside an engineer's side stick or other measuring stick that rests on the ground. The device is aimed at a previously marked location. The user can check the level of the grade by sliding the device up or down the measuring stick. However, this device provides no means of measuring the horizontal distance from the device to the previously marked location. Also, the user must always possess a separate measuring stick to determine grade level.
Devices have also been developed to measure horizontal points above a reference point. U.S. Pat. No. 5,092,057 discloses a device with a bubble level to ensure that the device is horizontal. It includes a perpendicular measuring tape to determine the vertical distance to a point. The device also has slidable locator members to mark two horizontal points at a desired distance apart. However, this device provides no means to measure the horizontal distance to a point.
SUMMARY OF THE INVENTION
The present invention provides a small, simple and easy-to-use elevation checking and measuring device that can also be used to measure points to the same level as a known point. The invention comprises a primary tape measure assembly which can be used alone or in combination with a secondary tape measure assembly. Both assemblies have mounting means for effecting their engagement. The primary assembly comprises a housing with a first mounting structure and the secondary assembly comprises a casing with second and third mounting structures. Such structures may include mechanical fasteners, Velcro fasteners, clamps, magnets, clips and matching undercut parts known in the art.
The housing and casing both include a retractable tape measure mechanism with a blade that can be extended to a desired length. The primary assembly blade is provided with an end part having a target portion for illumination from a focused light source emitted from the primary assembly.
For illustrative purposes, the first mounting structure is shown in the drawings as a vertical slot on at least one housing sidewall. The slot is designed to mate with a second or third corresponding mounting structure shown as a projection extending from the casing of the secondary tape measure assembly. This construction permits releasable engagement of the assemblies in multiple orthogonal orientations.
In one preferred orientation of the combined assemblies, the secondary blade, when extended from the secondary assembly casing, will be perpendicular to the primary blade when it is extended from the primary assembly housing. As so disposed, the primary blade can be used to measure horizontal distance to a point, while the secondary blade can be used to measure vertical distance.
In another preferred orientation, the extended blades are perpendicular to each other, but the secondary blade from the casing will be in a horizontal plane that is parallel to the primary blade. As so disposed, the primary blade will measure the distance to a known point and the secondary blade can measure the distance to a point in a related horizontal plane which is perpendicular to the primary blade.
The primary housing may have one or more level indicating means to show whether the primary housing is horizontal and not angularly canted. The primary housing also has a light source that projects a light beam adjacent to and longitudinally aligned with the primary measuring blade. When the primary blade is extended and the primary housing is horizontal, the light beam will illuminate the blade end part target portion. The primary housing includes a light actuation switch, electronic componentry and internal batteries to power the light source.
The invention provides a simple, quick and easy to use device to coordinate height and elevation measurements and to check the grade on a construction site. A single operator can use the device which is small enough to be stowed in a tool box or on a tool belt. The device can also be used to determine horizontal points on a wall from a known point. This is particularly useful in hanging pictures and wall decorations.
REFERENCES:
patent: D. 299437 (1989-01-01), Kull
patent: D. 311874 (1990-11-01), Ingram, II
patent: D. 332413 (1993-01-01), Douglas
patent: D. 349462 (1994-08-01), Douglas
patent: D. 373090 (1996-08-01), Bennett
patent: 1473877 (1923-11-01), Rome
patent: 2240753 (1941-05-01), Bouchard et al.
patent: 3191308 (1965-06-01), Lindenau
patent: 3514863 (1970-06-01), Moll
patent: 3526964 (1970-09-01), Clark, Jr.
patent: 3568322 (1971-03-01), Showers
patent: 3763569 (1973-10-01), Merlat
patent: 3812587 (1974-05-01), Elkins e
Bennett G. Bradley
Hovet Kenneth J.
Samora Arthur K.
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