Window frame deflection measurement device and method of use

A portable device for measuring deflection of a surface, comprising an elongate frame having a first end and a second end and a first datum surface, a first removable reference assembly adjacent the first end, a second removable reference adjacent the second end, a deflection gauge attached to the elongate frame between the first removable reference assembly and the second removable reference assembly, and wherein the deflection gauge engages and measures a deflection of the surface relative to the first removable reference assembly and the second removable reference assembly.

FIELD OF THE INVENTION

This invention relates generally to measurement of surface deflection of vertical surfaces and, more specifically, to measurement of deflection of a window or door frame.

BACKGROUND OF THE INVENTION

In many fields, it is often necessary to measure the amount that a vertical surface or frame has been bent or deflected. Such a situation arises in disaster recovery in response to wind damage or other accidents or natural disasters. Measurement of damage is necessitated by retrofit procedures which may be required as well as insurance recovery and insurance adjustment.

One of the major problems in measuring the deflection over longs spans, such as in large window frames, is the lack of convenient, portable tools to measure the deflection. A typical tool available is a mason's bubble level as well known in the art. A bubble level determines whether a surface is level and plumb (truly vertical or horizontal), but does not quantify the deflection of the surface.

U.S. Pat. No. 5,388,338 to Majors discloses an expandable screed level. The level has an open rectangular cross section and uses liquid bubble levels to determine slope. The device is expandable by adding additional sections at either end. The additional sections attach by means of a smaller rectangular cross section that fits inside the main body. The additional sections are retained in position by use of a latching mechanism. However, Majors makes no provision for measuring the displacement of a warp in a frame.

U.S. Pat. No. 5,433,011 to Scarborough et al discloses an expandable level. The level is expandable as a straight level, a square, a T-square and other shapes. Additional sections are added to the main body through a tongue and groove arrangement. A pressure screw is tightened to lock the pieces together. The device measures slope through use of liquid bubble levels. Each expansion piece contains at least one level. However, no provision for measuring deflection of a frame is provided.

U.S. Pat. No. 4,939,848 to Armstrong discloses an improved alignment gauge to check misalignment of the body of a vehicle. The device determines the distance between various physical points on the vehicle in order to aid in proper alignment. The device consists of a needle indicator attached at one end of a beam. The beam supports a horizontal and vertical liquid bubble level. The invention produces a precise result, but does not address the problems of ease of transport and use. It does not measure deflection along a long linear surface.

U.S. Pat. No. 7,497,022 to Aarhus discloses an extendable level. Telescopic extensions are contained within a main body of the level extension. Each terminates in an end piece. The extensions are supported by cross members. Each cross member and the main body includes a liquid bubble level. The invention does not measure depth or deflection.

U.S. Publication No. 2003/0033722 to Lanham discloses a telescopic leveling instrument having a body and telescopic extensions. The telescopic extensions are oriented horizontally or vertically. The extensions are marked to allow distance measurement. The main body includes a bubble level. The device does not measure depth or deflection perpendicular to the surface.

U.S. Pat. No. 5,303,480 to Chek discloses a device to measure the amount of deviation of a patient's facial symmetry from a “standardized norm.” The device consists of a rod shaped base and a portable probe that is movable horizontally. The base is placed against a patient's sternum and maintained at horizontal by monitoring a liquid bubble level. The probe is then set against various facial features and the horizontal and radial distance from the sternum to the probe is measured. However, the device does not provide a means to measure depth between two points on a particular surface or over long distances. Further, the device is incapable of measuring multiple points of deflection at the same time.

U.S. Pat. No. 4,691,443 to Hamilton, et al. discloses a vehicle alignment system. The system includes fittings connected to beams that allow access to a vehicle, while maintaining the measurement surfaces in horizontal or vertical orientation. Lasers are used to project X, Y and Z coordinates. The device is not portable. The device also does not provide a means to measure deflection of a freestanding vertical beam.

The prior art does not address the problem of measuring deflection in a vertical beam by a single individual. It is difficult and unwieldy for a single individual to hold prior art devices against such a window frame and measure the deflection accurately or consistently.

Therefore, a need exists for a device for measuring deflection of large surfaces, including window frames, which can be operated single-handedly. A need also exists for a deflection measurement device, which is portable and may be used in the field. Still further, a need exists for a simple uncomplicated device to measure deflection of a vertical beam at or around its center point. A further need exists for a device which is expandable to fit both large and small spans, without the need for additional tooling or calibration. A still further need exists for a device to measure many points of deflection over a surface simultaneously between a pair of reference points.

SUMMARY OF THE INVENTION

In one embodiment, the device comprises an elongate frame having an adjustable reference assembly located at each end. A gauge is located centrally in the elongate frame and positioned to measure a deflection from two calibrated reference assemblies. A centrally located handle is provided for ease of use, allowing a single individual to hold the device and manipulate the measurement gauge.

Expansion sleeves are provided that attach precisely and rigidly to each end of the frame in order to expand the span of the device. The reference assemblies are then removed and placed at the end of the additional lengths. The reference assemblies are designed and constructed so that re-calibration is not required. In another embodiment, the additional lengths incorporate additional pre-calibrated reference assemblies.

In another embodiment, the deflection at several locations along a given frame may be measured by repositioning the support frame, or, in another embodiment, by employing several gauges simultaneously.

In use, the device is first calibrated. Then, the reference assemblies are positioned against a span of window frame or other surface by manipulation of the elongate frame. The gauge in the elongate frame provides a reading of deflection.

DETAILED DESCRIPTION

Referring toFIGS. 1 and 2, the device includes elongate frame1. Elongate frame1is a rectangular tube having a base length of approximately three feet. Bottom surface1aof elongate frame1in a preferred embodiment is machined flat. The flat surface forms a first datum surface. Elongate frame1has a plurality of weight reduction holes4. Center cavity6is supplied for mounting of gauge2. End caps30and31are solid aluminum billets that are sized to fit precisely into the ends of the rectangular channel of elongate frame1.

In a preferred embodiment, the end caps are epoxied in place and machined flat and perpendicular to bottom surface1a. The end caps are perpendicular to bottom surface1a. End caps30and31each contain holes31aand31b, sized to receive reference assemblies15and16. End caps further include guide holes125and130. Recesses47aand48aare located at each end of elongate frame1. Catch support225aresides in recess47a. Catch support226aresides in recess48a.

In a preferred embodiment, elongate frame1may be made from an extrusion, milled from stock or cast. An aluminum magnesium alloy is preferred for cost and weight considerations. However, elongate frame1may be constructed of other rigid materials capable of maintaining a very low central beam deflection for moderate to light loads, on the order of 25 pounds. Lighter weight materials are preferred. For extremely high precision applications, stainless steel or titanium may be employed, resulting in extremely low deflections over large spans. Cross sectional shapes can vary. In a preferred embodiment, an “I” beam extrusion is employed having the highest rigidity to weight ratio available. Rectangular and box extrusions are also preferred as having high rigidity.

Handle8extends from the center of elongate frame1. The handle is centrally positioned between the reference assemblies to provide equal pressure to the reference assemblies when in use and to facilitate ease of positioning by a single user. Handle8is attached to the elongate frame1using screws8aand8bpassing through the inside of elongate frame1or by welding. Other methods of removable or permanent attachment may be employed as known in the art. A removable handle is preferred to aid in compact storage for shipment.

Gauge2is operatively positioned in mounting hole6. Gauge2includes probe12, retention knob10a, and data read out10b. Probe12extends radially from the bottom of gauge2through access hole12ain elongate frame1. Hole12ais sized to avoid interference with the radial movement of probe12. Similarly, retention knob10aextends radially through access hole12bin the top of elongate frame1. Access hole12bis sized to allow free motion of the retention knob. Probe12is spring loaded to facilitate ease of use. Retention knob10afollows the movement of probe12. Retention knob10asecures probe12to gauge2preventing over-extension or loss of probe12due to the spring.

In a preferred embodiment, gauge2is a 543-683B electronic digital indicator manufactured by Mitutoyo of Tokyo, Japan. Another viable option is a depth gauge manufactured under part number CEN44345 and offered for sale by Central Tools/Central Lighting. In another embodiment, the gauge can include an electronic memory including time and date indexing so that the time and date of measurements taken can be recorded. Furthermore, gauge2may include a memory for alphanumeric tagging of each measurement so that notes may be made as to the location of the window frame being measured. In this embodiment, electronic downloading of this data is provided to a laptop computer for later use. An RFID tag may be applied to the physical window frame corresponding to the deflection tagging for later positive location and correlation with the deflection measurement.

In another embodiment, gauge2may be an optical or acoustic distance measuring device. An example of an optical measuring device is Leica Disto's model 740690, which measures distance via a laser. An example of an acoustic measuring device is the Intellimeasure model 77-018 from Stanley Tools, which measures distance via ultrasonic waves. Other such measuring devices are known in the art and may include wireless data capture via a computer. Gauge2may also include a button to zero the readout at a given height during calibration.

While preferred embodiments of this device are described as having a manually adjustable gauge, other gauges and measurement devices may be utilized. Further, seals for moving parts are not required for all uses and types of gauges.

Referring toFIG. 3a, the span of the device may be increased by adding extensions40and41to each end of elongate frame1. Referring toFIG. 3b, in a preferred embodiment, extensions100,105, and110are different lengths of 3 inches, 6 inches and 12 inches, respectively. Other lengths of extensions may be utilized. Extensions100,105and110are constructed of hollow rectangular channel having solid ends101aand101b,106aand106b, and111aand111b. The solid ends are epoxied into each end of each extension, respectively. Bottom surfaces1009,1089, and1109are each machined flat to match bottom surface1aof elongate frame1. The bottom surfaces form datum surfaces for calibration. Each solid end is also machined to be perpendicular with the bottom surfaces.

Each extension includes a set of guide pins115and120and a set of guide holes116and121. Guide holes116and121are sized to provide a close fit with guide pins115and120. Guide pins115and120are different diameters and different lengths so that the extensions may be assembled with the elongate frame in the proper orientation.

Referring toFIG. 3c, the guide pins are engaged with corresponding guide holes until one or more extensions meets elongate frame1. The extensions are attached to the elongate frame singularly or in groups, thereby variably extending the length spanned by the device.

Referring toFIGS. 3dand4, an extension is removably engaged with elongate frame1with latch assembly200. Toggle arm245is advanced allowing latch210to engage catch230. Toggle arm200is then rotated forcing latch210under catch support225, thereby releasably securing the extension to the elongate frame.

Toggle support205resides in recess47alocated on each extension. Toggle support205is secured in recess47awith bolts235aand240a. Toggle arm245is pivotally supported by toggle support205through hinge pin215. Toggle arm245includes toggle pin220which pivotally supports latch210. Each catch support is secured to the elongate frame by way of retaining screws235and240. Each catch support includes a catch230.

By way of example,FIG. 4shows the construction of catch support226aand catch230as well as the location of the retaining screws235and240. Catch support226aand catch230are formed from stamped steel plate in a preferred embodiment.

In another embodiment, each extension includes a pre-calibrated reference assembly in relation to elongate frame1.

Referring toFIGS. 3eand3f, reference assemblies15and16are attached to elongate frame1. Elongate frame1also includes a set of threaded holes for receiving mounting screws for reference assemblies15and16. The threaded holes are shown by way of example inFIG. 3eas120and121. Reference assemblies15and16include mounting blocks3and5. Referring toFIG. 3f, by example, the top surface of mounting block50is machined flat to match the bottom surface1aof the elongate frame. The flat surfaces form second and third datum surfaces from which the device is calibrated. Mounting blocks3and5are removably attached to elongate frame1. Mounting blocks3and5include holes107and108. Bolts52and54pass through holes107and108in mounting blocks3and5and thread into holes120and121in end cap31. Each mounting block includes a threaded hole shown as17afor receiving a threaded contact support18. Threaded contact support18is retained in threaded hole17aby locking nut14. The threads are standard ASTM pitch. In high precision embodiments, threads with lesser pitch may be employed.

Each reference assembly further includes contact pad, shown by example as9. In a preferred embodiment, each contact pad includes a flexible neoprene gasket. In other embodiments requiring greater accuracy, each contact pad may be comprised of a suitable rigid material such as nylon, delrin, aluminum or polished stainless steel. In applications where static discharge or contact with high voltage is a concern, the contact assemblies can be formed of bakelite or asbestos.

In a preferred embodiment, when extensions are added, the mounting blocks, along with contact assemblies15and16are removed from elongate frame1and attached to an extension by use of threaded bolts52and54. Movement of contact supports17and18with respect to mounting blocks3and5is not required, and their calibrated height is retained by locking nut14. Thus, relocation of contact assemblies15and16onto the extension without recalibration of gauge2is accomplished. Other extensions are added in a similar manner.

Referring toFIG. 5, in another embodiment, the device is configured to simultaneously take multiple measurements, such as when a vertical surface has been deflected in more than one plane and/or in more than one location. In this embodiment, gauges51,53,55,57, and59reside in holes91,93,95,97, and99, respectively. Each gauge includes a retention knob61,63,65,67, and69, respectively, and probe71,73,75,77, and79, respectively.

In use, the device must first be calibrated. To calibrate the device, contact pads7and9are positioned on a flat calibration surface. A gauge block of known height, typically half of the probe's travel distance, is placed on the flat calibration surface and under the machined bottom surface1aof elongate frame1. Contact supports17and18are adjusted until elongate frame1comes to rest on the gauge block. Probe12of gauge2is spring loaded and provides a measurement of deflection when contact pads7and9come to rest against the surface. Gauge2is adjusted so that the gauge provides a neutral reading of the calibration surface. If additional contact assemblies are included on the extensions, they are attached to elongate frame1and calibrated in a similar fashion.

In another calibration embodiment, the gauge blocks may be replaced by a measurement device. A measurement device, such as a machinist square or a set of calipers is used to determine the distance between contact pads7,9and machined bottom surface1a. Contact pads7and9are then placed against a flat calibration surface and gauge2is zeroed against the surface. Alternatively, a measuring device may be used to set probe12at the same distance as contact pads7and9. Probe12is then zeroed. It will be appreciated by those skilled in the art that zeroing of the gauge and extensions may be accomplished utilizing a multitude of methods without departing from the intent and scope of the invention.

Where gauge2has been properly calibrated, a positive displacement reading will show a deflection of frame20inward22(away from the device), a negative reading will show a deflection outward24(toward the device) and a reading of zero will show no deflection.

Referring toFIGS. 6A and 6B, in use, the device is positioned on a vertical, free standing surface, such as frame26. Contact pads7and9are located at the extremities of the vertical surface and positioned by manipulating the elongate frame by the handle. Probe12meets frame26prior to either contact pad7or9. As contact pads7and9move toward the surface, gauge2makes a measurement. Generally, the device will be located so that probe12meets frame20in the center, as this is often the area of greatest deflection. However, the device may be used to measure multiple locations along frame26. Where RFID tag20ais to be employed, it is affixed to frame20, and its serial number is recorded and correlated with the deflection reading. In a multiple gauge embodiment, once contact pads7and9have been positioned, readings from each of the gauges may be taken and recorded simultaneously.

It will be appreciated by those skilled in the art that modifications can be made to the embodiments disclosed and remain within the inventive concept. Therefore, this invention is not limited to the specific embodiments disclosed, but is intended to cover changes within the scope and spirit of the claims.