Assistive apparatus for a grinding tool

Abstract

An apparatus to assist a worker in grinding residue from target weld sites on a beam having a width and a longitudinal axis may include a rolling cart configured to traverse the peaks and valleys of a corrugated deck pan in a direction parallel to the longitudinal axis. The rolling cart may carry a support arm having a tool holder for retaining a hand-held grinding tool. A slidable rod assembly may be coupled to the support arm to enable movement of the support arm horizontally between retracted and extended positions across the width of the beam. A hinged arm may be connected between the slidable rod assembly and the support arm to enable movement of the support arm between an upward position where the hand-held grinding tool is disengaged from the beam and a downward position where the grinding tool engages the target weld site for grinding.

Description

BACKGROUND

[0001] The present invention relates generally to grinding equipment used to grind surface residue from pre-defined weld sites on structural I-beams used in bridge and building construction, and in particular to a system that assists a worker in performing this grinding operation to reduce required physical effort and injuries associated with grinding, and to increase productivity.

[0002] In steel erection projects, for example, bridge and building construction, steel studs are typically manually placed onto the surfaces of steel beams into ceramic ferrules, and then are welded in place onto the beam, typically an I-beam. Concrete is poured over a corrugated deck pan connected to the beam. The concrete hardens around and engages the shear studs in a manner which allows the beam to become more resistant to bending.

[0003] In advance of welding, the pre-defined weld sites on the beam are preferably prepared by removing all surface contaminants and residue to help ensure the integrity of the welds. Often, these weld sites are marked for grinding using paint marking, for example. Presently, grinding of the weld site is accomplished by manual grinding the surface of the beam using a hand-held power grinding tool or deck saw. Unwanted surface contaminants and residue are removed by using the grinding tool to scrape the weld site from side to side until an area typically at least 1.5” square or larger is treated. For heavier debris, the worker may utilize angle grinders or various other power tools. This is a slow and arduous process requiring the worker to repeatedly bend over and apply force on the grinding tool at each of numerous welding sites. The slow speed of this process increases construction time and costs. This repetitive and physically demanding work leads many workers to suffer significant lower back and knee injuries due to repeated stress while bending over for long periods of time.

[0004] Attempts have been made to develop technology to remove pressure from the worker’s back while utilizing these tools, as the tools are heavy and require application of significant downward force during the grinding process. Significant sums are paid for compensating workers for injuries sustained while utilizing these tools, and many workers are left with permanent back injuries. Some of these efforts have involved fully automated grinding systems that are very large, heavy, expensive, and complex. Accordingly, such systems are complex to operate and require powerful equipment to lift and move them into place.

[0005] Accordingly, there is a need for an apparatus that will reduce stress on the operator, but is relatively lightweight, simple to operate, and is easily maneuverable without the use of heavy lifting equipment.SUMMARY

[0006] An apparatus to aid in grinding the surface of a steel beam at pre-marked target weld sites is disclosed. The apparatus is arranged to be situated on the surface of a corrugated deck pan aligned with the I-beam having a width and a longitudinal axis. The apparatus includes a rolling cart arranged to traverse the peaks and valleys of the corrugated deck pan as it moves parallel to the beam’s longitudinal axis. A support arm carried by the rolling cart provides a tool holder arranged to retain a hand-held grinding tool therein. A slidable rod assembly positioned on the rolling cart is coupled to the support arm to enable movement of the support arm between retracted and extended positions across the width of the beam. A hinged arm connected between the slidable rod assembly and the support arm pivots about a horizontal axis to enable movement of the support arm vertically between an upward position where the hand-held grinding tool is disengaged from the beam surface and a downward position where the hand-held grinding tool engages the target weld site for grinding.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a more complete understanding of the present invention, reference is made to the following detailed description of embodiments considered in conjunction with the accompanying drawings, in which:

[0008] FIG. 1 is a perspective view of a first embodiment of an assistive apparatus for a grinding tool positioned over a corrugated deck pan at a site of construction of a building or bridge;

[0009] FIG. 2 is a perspective view the first embodiment of the assistive apparatus for a grinding tool;

[0010] FIG. 3 is side elevational view of the first embodiment of the assistive apparatus for a grinding tool;

[0011] FIG. 4 is an image of a second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly in a straight, retracted, and disengaged position;

[0012] FIG. 5 is an image of the second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly in a straight, retracted, and engaged position on a weld site;

[0013] FIG. 6 is an image of the second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly disposed in a straight, extended, and disengaged position;

[0014] FIG. 7 is an image of the second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly disposed in a straight, extended, and engaged position on a weld site;

[0015] FIG. 8 is an image of the second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly disposed in a rotated, extended, and disengaged position;

[0016] FIG. 9 is a perspective view of a third embodiment of the assistive apparatus for a grinding tool;

[0017] FIG. 10 is a perspective view of the third embodiment assistive apparatus for a grinding tool;

[0018] FIG. 11 is a partial perspective view of a portion of the third embodiment assistive apparatus for a grinding tool of FIGS. 9 and 10, showing a quick-release assembly; and,

[0019] FIG. 12 is second partial perspective view of a portion of the third embodiment assistive apparatus for a grinding tool of FIGS. 9 and 10, showing a quick-release assembly.DETAILED DESCRIPTION

[0020] The following disclosure is presented to provide an illustration of the general principles of the present invention and is not meant to limit, in any way, the inventive concepts contained herein. Moreover, the particular features described in this section can be used in combination with the other described features in each of the multitude of possible permutations and combinations contained herein.

[0021] All terms defined herein should be afforded their broadest possible interpretation, including any implied meanings as dictated by a reading of the specification as well as any words that a person having skill in the art and / or a dictionary, treatise, or similar authority would assign particular meaning. Further, it should be noted that, as recited in the specification and in the claims appended hereto, the singular forms “a,”“an,” and “the” include the plural referents unless otherwise stated. Additionally, the terms “comprises” and “comprising” when used herein specify that certain features are present in that embodiment but should not be interpreted to preclude the presence or addition of additional features, components, operations, and / or groups thereof.

[0022] The following disclosure is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of the invention. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In this description, relative terms such as "horizontal," "vertical," "up," "down," "top," "bottom," as well as derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including "inwardly" versus "outwardly," "longitudinal" versus "lateral" and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as "connected" and "interconnected," refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both moveable or rigid attachments or relationships, unless expressly described otherwise, and includes terms such as "directly" coupled, secured, etc. The term "operatively coupled" is such an attachment, coupling, or connection that allows the pertinent structures to operate as intended by virtue of that relationship.

[0023] Referring FIGS. 1-3, an assistive apparatus for a grinding tool is shown and is generally designated at 100 and includes a tool support assembly 112 having a tool mount 110, a sliding assembly 114, a turntable 116, and a roller undercarriage 118.

[0024] In FIG. 1, the grinding cart 100 is shown positioned on a corrugated deck pan 120 and adjacent a conventional steel I-beam 122. The deck pan 120 and I-beam 122 may be utilized in the construction of buildings and bridges. The deck pan 120 is formed of standard gauge metal decking such as 16-gauge, 18-gauge, and 20-gauge steel, and may comprise a variety of configurations. However, as best shown in FIG. 1, it is common for the deck pan to have an undulating structure having alternating peaks and valleys. The deck pan 120 is configured to hold poured concrete that eventually forms a floor for a building or a road bed for an elevated road surface. The I-beam 122 may include a planar top surface 124 and a longitudinal axis that runs perpendicular to the sequential peaks and valleys of the deck pan 120 positioned adjacent thereto. The I-beam 122 may include a plurality of target weld sites on the top surface 124 that must be prepared in advance of welding the shear studs thereto. The target weld sites may be equally spaced along the length of the I-beam. Some target weld sites may be positioned in a line along the length of the I-beam 122 located closer to the deck pan, and other target weld sites may be positioned along another line located further away from the deck pan120.

[0025] The grinding cart 100 may include a base 111, sized and shaped to support the other components, including the turntable 116, the tool mount 110, the tool support assembly 112, and the sliding assembly 114. The turntable 116 and sliding assembly 114 are also collectively referred to as a mount assembly, the purpose of which is to support and provide for movement of the tool mount 110.

[0026] A roller undercarriage 118 (also referred to more generally as running gear) is located beneath the base 111 and is shown positioned on the corrugated deck pan 120. The roller undercarriage 118 is adapted to enable the grinding cart 100 to be moved along the deck pan in a direction parallel to the length of the I-beam 122 (shown by Axis A in FIG. 2), to assist the worker in positioning a hand-held grinding tool 134 retained within the tool mount 110 over the target weld sites. As best shown in FIG. 3, in this embodiment, the roller undercarriage 118 comprises plurality of closely-spaced and parallel rollers 164 mounted to rails 162a and 162b positioned at opposite ends of the roller undercarriage 118.

[0027] Many other types of powered and unpowered running gear could be used in alternate embodiments. For example, and as shown in FIGS. 4 through 8, an electric track drive system could be used, comprising two rubber tracks driven by a DC motor which is powered by least one battery. An electric motor powered rubber track system is particularly suitable for this application because it provides stability as the mobile platform moves across the undulations of the corrugated deck pan and because generators are commonly available on job sites in which the mobile platform is used. Other embodiments, different types of ground-engaging elements could be used, such as rollers, tracks (rubber, rigid plastic, or metal), and wheels. In addition, any suitable means for powering the running gear could be used, such as other types of electric motors, petroleum-powered engines, and fluid-driven pumps. In embodiments in which the running gear is powered, movement of the running gear may be controlled from the handlebars 146 located on the tool support assembly 112.

[0028] The tool mount 110 may include a collar 136 through which the hand-held grinding tool 134 may be disposed, and a support plate 138 to retain the collar 136 against the tool support assembly 112. Once retained within the tool mount 110, the grinding tool may be plugged into a conventional AC outlet available on the jobsite for grinding.

[0029] Referring now to FIGS. 9-12, in an alternative embodiment, the tool mount 310 is shown as including a collar 336, a support plate 338, and a thumb screw. The collar 336 may include a central opening through which the grinding tool 134 may be disposed and may include captive screws to retain the grinding tool 134 therein. By loosening the thumb screw, the collar 336, with the grinding tool 134 retained therein, may be quickly released from the support plate 338 without the need for special tools. In this manner, the tool mount 310 provides the ability quickly exchange different grinding tools onto the grinding cart 100 based upon the surface residue encountered on the I-beam 122 or to replace worn out grinding wheels and blades. In an alternative implementation, the tool mount 110 could be adapted to permanently retain a dedicated grinding tool.

[0030] In the embodiments shown herein, the grinding tool is a rotary grinder. In other embodiments, the tool mount 110 could be adapted to removably retain other types of abrasive tools, such as drum-based surface conditioning tool, a belt sander, an orbital sander, an oscillating tool with an abrasive attachment. In yet other embodiments, a permanent, built-in abrasive tool could be provided in place of the tool mount 110.

[0031] The tool assembly may include a telescoping handle 144 and handlebars 146 extending horizontally therefrom. The telescoping handle 144 may be provided in separate parts such that a first part moves or slides in and out with respect to a second part to adjust the length of the handle 144 and height of the handlebars 146. The handle 144 may include a plurality of equidistantly spaced through-holes to fix the handlebars 146 at a suitable height to enable a worker to remain standing in an upright position during grinding. As shown in FIGS. 1-3, the handlebars 146 may bend at a slight angle and may include handgrips at each end. The tool support assembly 112 is adapted to enable the user to perform a grinding operation and move the grinding tool to the next weld site without bending over.

[0032] Referring now to FIG. 2, the tool support assembly 112 may be attached to a frame 142 through a hinged arm 140 having pins located at its opposite ends. The pins enable pivotal movement of the hinged arm 140 about axes C and D to enable movement of the tool support assembly 112 from an upward position (see FIG. 4) where the grinding tool 134 is disengaged from the target weld site on the I-beam 122 to a downward position (as shown in FIG. 2) where the grinding tool 134 engages the target weld site for removal of surface contamination therefrom.

[0033] When performing a grinding operation, the worker may apply a downward force on the handlebars 146, causing the tool support assembly 112 to move from the upper position to the lower position. Preferably the range of motion provided by the tool support assembly 112 is sufficient to enable an abrasive element (such as a grinding disk) of the grinding tool 134 to extend below the running gear when the lower position. This ensures that the grinding tool 134 is able to grind weld spots in a variety of job site environments. The range of motion preferably enables the grinding tool 134 to be positioned well above the i-beam 122 when in the upper position, to provide clearance during movement of the grinding cart 100, as well as to facilitate maintenance and replacement of the grinding tool 134.

[0034] The tool support assembly 112 may be provided with a tensioning spring 166, also shown at 266 in FIGS. 4 through 8, to apply a biasing force against this downward force. In this manner, the upward force needed by the worker to lift the grinding tool 134 from the target weld site is lessened due to assistance provided by the tensioning spring 166. This also will cause the tool support assembly 112 to return to the upper position when released. In other words, the support assembly 112 is biased into the upper position by the tensioning spring 166.

[0035] As best shown in FIGS. 4-8 of the second embodiment, the tensioning spring 266 may be connected between a spring plate 268 and a support plate 238 of the tool mount 210. The tensioning spring 266 may be adjustable to adjust the amount of biasing force where grinding tools of different weights are utilized. Alternatively, multiple alternative tensioning springs may be provided based upon the weight of the grinding tool employed and the amount of biasing force required. In other embodiments, other types of linear force elements could be substituted for the spring, such as a gas cylinder, elastomeric rubber strap, or flexible leaf spring element.

[0036] The tool support assembly 112 may attach to the sliding assembly 114 through the hinged arm 140 and the frame 142. The sliding assembly 114 may include a plurality of rods 150a, 150b, and 150c, each rod extending through a corresponding rod gliders 152a, 152b, and 152c, the rod gliders mounted to the turntable 116. At their distal ends, the rods 150a, 150b, and 150c connect to a rod block 148c. The rods 150a, 150b, and 150c extend through openings in a rod block 148b and are attached at their proximal ends to a rod block 148a. The rod blocks 148a and 148b may be mounted to the frame 142 in a spaced-apart relationship. As the worker pushes forward or pulls back on the handlebars 146, the rods 150a, 150b, and 150c travel through the rod gliders 152a, 152b, and 152c along an axis 2 (FIG. 2 ) from a retracted position to an extended position. In this manner, the worker can position the grinding tool 134 at desired locations between these positions to reach target weld sites on the I-beam 122 positioned at locations closer to and further away from the deck pan 120. Once the worker applies a downward force on the handlebars 146 to engage the grinding tool 134 with the target weld site, the handlebars 146 may be utilized to move the grinding tool 134 back and forth between the extended and retracted positions for effective grinding.

[0037] The worker can also apply a lateral force to the handlebars 146 to rotate the turntable 116 in either a clockwise or counterclockwise direction to adjust the position of the grinding tool 134 along an arc to reach desired locations of target weld sites. Once engaged with the target weld site, in addition to moving the grinding tool 134 in the back-and-forth directions, the worker can apply lateral forces to the handlebars 146 to rotate the grinding tool 134 along an arc to grind out a substantial surface area of the target weld site without needing to move the grinding cart 100. The turntable 116 may optionally include a pin, other structure, to selectively lock rotation of the turntable 116.

[0038] In one embodiment, the sliding assembly 114 may include a motor assembly coupled to a gear assembly to control sliding movement of the rods 150a, 150b, and 150c through the rod gliders 152a, 152b, and 152c to reduce the amount of effort required by the worker.

[0039] The sliding assembly 114 may include an electrical or mechanical braking system responsive to worker actuation to apply a braking force to the rods 150a, 150b, 150c to retain the grinding tool 134 in a particular extended or retracted position. The braking force may be a compressive force applied in a normal direction to opposite sides of the rods 150a, 150b, 150c. Optionally, the braking system may continually apply a braking force onto the rods 150a, 150b, and 150c, and only in response to the worker actuating a button, such as located on the handlebars 146, will the braking force be released. A signal may be sent to actuate an electrical solenoid or mechanical component to release the brake. By utilizing the brake, the worker can easily move the head of the grinder tool to a target weld site.

[0040] Referring now to FIGS. 4-8, a second exemplary implementation of a grinding cart 200 is shown. It should be understood that elements of grinding cart 200 that are shared with the first embodiment (grinding cart 100) are represented by reference numerals increased by a factor of 100. For example, the tool support assembly 112 of the grinding cart 100 corresponds to the tool support assembly 212 of the grinding cart 200. In the interest of clarity, some features of this embodiment that are shared with the first embodiment are numbered in FIGS. 4-7, but are not repeated in the specification.

[0041] In FIG. 4, the worker has moved the tool support assembly 212 to a retracted and upward / disengaged position such that the head of the grinding tool 234 is positioned over but not in contact with a target weld site located on the I-beam 222 at a position closer to the corrugated deck pan 220. In FIG. 5, the worker has applied a downward force to the handlebars 246, moves the tool support assembly 212 into a downward / engaged position, which enables the grinding tool 234 to grind that target weld site. In FIG. 6, the worker has moved the tool support assembly 212 to an extended and disengaged position such that the head of the grinding tool 234 is positioned above but not in contact a target weld site located on the I-beam 222 at a distance further from the corrugated deck pan 120. In FIG. 7, the worker has applied a downward force to the handlebars 246 to grind that target weld site. In FIG. 8, the worker has applied a lateral force to the handlebars 246 resulting in a counterclockwise rotation of the tool support assembly 212 for grinding another target weld site.

[0042] FIGS. 9 - 12 illustrate a third exemplary implementation of a grinding cart 300. It should be understood that elements of grinding cart 300 that are shared with the first and / or second embodiments (grinding carts 100 and 200) are represented by reference numerals increased by a factor of 100 or 200 (respectively). For example, the tool support assembly 212 of the grinding cart 200 corresponds to the tool support assembly 312 of the grinding cart 300. In the interest of clarity, some features of this embodiment that are shared with the first or second embodiment are numbered in FIGS. 9 through 12, but are not repeated in the specification.

[0043] One advantage of the grinding cart 300 is that the sliding assembly 314 is sufficiently elevated above the turntable arranged to be positioned a sufficient distance above the turntable 358 so as to enable a full 360-degree unobstructed rotation of the sliding assembly 314. This expands the ability of the grinding tool 334 to reach more target weld sites on the I-beam 122 as well as on I-beams located adjacent thereto without moving engaging the drive assembly of the grinding cart 300.

[0044] Movement of the sliding assembly 314 is controlled by a ball gear drive system 376. The ball gear drive system 376 is preferably controlled by a two-way temporary switch (not shown) located on the handlebars 346 that enables the user to selectively extend or retract the sliding assembly 314. The ball gear drive system 376 prevents the ball gear drive system 376 from extending or retracting when it isn’t energized, which eliminates the need for a separate braking system.

[0045] Referring to FIGS. 11 and 12, the tool mount 310 is shown in greater detail. In this exemplary embodiment, a quick-release plate 378 is releasably affixed to the support plate 338 by a pair of bolts 380a. 380b. When the thumb screw 382 is tightened, the bolts 380a, 380b hold the quick-release plate 378 in place with a friction fit. When a tool change is desired, the user loosens the thumb screw 382, which loosens the bolts 380a, 380b and allows the quick-release plate 378 to be moved downwardly. This results in the bolt 380a disengaging an upper slot 384 and the bolt 380b to move to an enlarged portion 386 of a lower slot 388, which enables the quick-release plate 378 to be removed from the support plate 338.

[0046] In an embodiment, a pedal may be placed near the end of the head of the grinding tool to align the grinding tool head over the target weld site as well as to enable the application of force that may be required in addition to the force applied through the handlebars by the operator’s upper body. Because the pedal would be placed in proximity to the head of the grinding tool, it may be necessary to provide a protective shield for the operator’s foot and lower leg in the event of a malfunction of the grinding tool or its blade while using the assistive apparatus. The shield may be formed of any suitable metallic or rigid plastic material typically used for such applications, e.g., a polycarbonate.

[0047] In an embodiment, the grinding cart 100 may be fitted with a lifting jack at one end that may be controlled through an operator interface for the purpose of lifting and transporting heavy materials on the jobsite through use of the motorized capabilities of the grinding cart 100.

[0048] In another embodiment, the grinding cart 100 may be sized to fit within the dimensions of a standard doorway width so that the grinding cart 100 can be utilized for grinding surface residue on floors such as concrete in buildings and scraping carpet up inside.

[0049] In another embodiment, the grinding cart 100 provides for autonomous operation in that an operator can move the entire grinding cart 100 through the use of additional operator controls placed on the handlebars 146 to control a motorized conveyor system to move the grinding cart 100 in any desired direction. This conveyor system will include two separate sides with a separate motor and gearbox for each side that will be connected to a controller. The output of the gearboxes will drive a sprocket that connects to a belt of frictional rubber-like material for movement on a variety of surfaces but in most cases on the top surface of the corrugated deck pan which is galvanized stainless steel. During the operation of the grinding cart 100, the direction will be parallel to the length of the I-beam surface 124 which would also be parallel to the path of travel on the resulting road surface. The controls would allow for adjustment of speed as well as the ability to rotate and to move backward and forward along the length of the I-beam surface. The system can move at a variety of speeds as indicated by operator controls that can approach human walking speeds.

[0050] In another embodiment, the grinding cart 100 may include an automated indexing feature allowing for pre-programmed spacing and timing to allow for the cart to be programmed to move in predetermined distances in predetermined durations of time. This functionality would enable the operator to relinquish control of motion of the cart and focus solely upon using the grinding tool to grind the target weld sites on the I-beam. During autonomous operations, the system may have the ability to auto-detect obstacles using, for example, a SICK safety scanning lidar for detection and registration of obstacles that would impede the motion of the cart. This would prevent unwanted collisions with disregarded materials and debris on the jobsite as well as workers walking in the motion path of the system. During autonomous operation of the grinding cart 100, a lidar system, possibly 2D, could be used to scan the surface to detect proximity to the end lip of the corrugated deck pan to correct for alignment to prevent the grinding cart 100 from moving off the deck pan 120 and onto the surface of the I-beam beam 122. The motorized track system provides the ability to move off of the deck pan onto the beam surface or vice versa. The motorized track system also enables motion of the grinding cart 100 across a variety of surfaces on the construction site to reach a destination where a road surface or similar flat surface may not be readily available.

[0051] In another embodiment, the motion of the operator during the rotation and retraction / extension can be assisted or fully automated through motorized enhancements. This can be accomplished for the extended and retracted movement by placement of a linear actuators controlled through a motor linked to various buttons located on the operator’s handle interface to enable the operator to easily extend or retract the rods 150a, 150b, and 150c. This actuator could be a ball-screw drive to eliminate the need for an electrically or mechanically actuated brake system. It could also be a conventional belt drive or similar actuator. Alternatively, movement of the turntable 116 could be accomplished through an actuable button disposed on the handlebar interface to effect clockwise or counterclockwise rotation of the turntable enabling the operator to apply minimal force to rotate the turntable. This could be performed through an electrical motor system coupled to a gearing system connected to the turntable with a toothed gear exterior.

[0052] In another embodiment, the grinding cart 100 may include an additional set of rods 150a, 150b, and 150c that would be controlled in the same manner as described above. This set of rods would run perpendicular to the original set used for extensions / retraction movement to allow for an X-Y Cartesian motion. This secondary set of rods would provide for motion of the grinding tool in a direction parallel to the length of the beam and could be controlled through a similarly actuated mechanical or electrical braking system, or alternatively, through an electrically assisted motion as described with the extension / retraction rods through operator switch controls on the handlebar interface. Additionally, the use of linear sliding rails could be replaced entirely with purely linear actuators.

[0053] In another embodiment, the indexing motion feature could be expanded to the motion of these two perpendicular motorized assisted rod systems. The grinding cart 100 could move to the appropriate indexed position and wait for the operator to perform the grinding operation before moving to the next position as indicated through an operator input command or through a sensor detecting quality of surface residue.

[0054] Additionally, wireless controls can be provided to transmit information to a controller computer on the grinding cart 100 instead of requiring hard-wired connections for controlling the various operator controls of the grinding cart 100. This wireless system will consist of an operator handle box powered through a DC battery and RF link coupled to a compatible RF device in the control box directly mounted on the cart. This will eliminate the need for hard wiring and will prevent cable damage resulting from rotational and translational movement of the grinding cart 100 during use. The RF controls could also be embedded in a controller entirely off of the grinding cart 100 to allow a second worker not performing the grinding to move the grinding cart 100 through the controls just as the grinding tool operator could.

[0055] In a motorized embodiment, the grinding cart 100 can connect to an AC power source used to distribute power to the grinding tool as well as to the locomotion and control systems. The AC power source can also be used to charge a DC battery. The DC battery could be used to power to the grinding tool as well as to the locomotion and control systems. Alternatively, the grinding cart 100 could be adapted to only power the grinding tool through AC power.

[0056] In another embodiment, the rolling cart may be provided with rubber material treads, the treads being wider than the valleys of the corrugated deck pan such that the rolling cart will not get caught in the valleys of the corrugated deck pan when in any direction over the corrugated deck pan.

[0057] In another embodiment, during the autonomous operation, the operator may want to halt system operation as it moves from indexed grind row to row, or from grind spot to grind spot. The operator may want to halt autonomous operation temporarily for safety reasons, to use the manual or manually-assisted controls, or to return to inadequately ground locations. The operator interface on the handlebar provides an actuator that can be depressed, or data entered when the operator wishes to halt system operation. The system may also be provided with an auditory or a hand-motion detection system enabling the operator halt a pre-programmed routine using auditory or hand-motion commands.

[0058] In another embodiment, a button may be provided on the handlebar interface for moving from one row of target weld sites to the next instead of employing the pre-programmed timing and spacing for the system and needing to fit into the time constraints which may not always be realistic as the operator requires breaks.

[0059] In another embodiment, during autonomous operation mode, a visual CMOS camera could be used to detect paint marks placed on the beam surface to represent the rows of target weld sites. This visual recognition can occur through machine vision object recognition techniques or possibly through the use of an AI system trained with a neural network with information on the expected paint markings. These paint markings can then be coordinated through a localized coordinate system to place the grinding tool head directly in line with the rows of target weld sites. The operator would then engage the grinds through retraction and extension of the tool support assembly 112. This would provide visual feedback for grinding tool placement on the system with the motion being able to be automated based on machine vision.

[0060] In another embodiment, the grinding cart 100 may collect data from various sensors throughout the operation period. This data could be time stamped and could include visual images, lidar data, operator inputs, safety warnings, motor actuation with respective encoder data, and motor positions for the rods used for the operator placement over the target grind areas. The data could be used to compute analytics relating to average grind times and grind efficiency, and for future AI training purposes.

[0061] In another embodiment, the grinding cart 100 may include surface restoring tools such as a debris removal blower or vacuum system to remove loose debris from the cleanly ground sites. This surface residue is commonly removed to prevent defective welds. Currently, workers use a leaf blower or shop vacuum to remove such surface residue and debris after grinding.

[0062] In another embodiment, an exoskeleton to assist in tool lifting could be used in combination with the grinding cart 100 to ease lifting. This exoskeleton can be worn by the operator to remove pressure from commonly stressed points like the lower back and hips by transferring weight into a belt-like harness. As well, a zero-gravity style assist can also be mounted onto the cart for similar purposes of easing lifting of tools.

[0063] In another embodiment, tool holders may be provided to enable changing out of a variety of available tools throughout a workday. These tool holder holders would permit the operator to easily swap an existing tool holder for one holding a needed tool as judged by the operator’s perception of the quality of the ground surface. The tool holder is intended to enable the interchangeability of the end tool depending on the degree of severity and type of surface residue. This could also be used in high-rise building construction, on decks of aircraft carriers for stud welding, and many others. Other tools could include but are not limited to chippers and scrappers.

[0064] In another embodiment, multiple grinding tools may be attached at the same time with adjustability for spacing between the grinding tools for purposes of grinding multiple rows of target weld sites simultaneously with a singular applied motion of the operator. The multiple grinding tools could also be used to grind away multiple grind spots on a single row simultaneously. A grinding tool such as a commercially available bench top grinder may be employed with its abrasive stone being applied to the target weld site with necessary modifications from the traditional use case. A single rotating shaft may be used with several grinding tool heads simultaneously that can be the same or vary in composition.

[0065] In another embodiment, surface residue can be detected through a laser system that produces a beam of a known radiance and then measures the radiance received back compared with an expected standard of reflection radiance.

[0066] In another embodiment, along with the aforementioned tools, a laser removal system may be used to remove surface debris. This system may include a point laser with a wavelength known to remove debris present on a target surface connected in a safety proofed enclosed box that gets lowered flush onto the surface and has the laser attached on an XY motion system that will move the laser point across the target weld location in an automated fashion. Sensors can be built into the enclosed box to contact the ground surface and engage magnets for purposes of more safely affixing the system onto the surface of interest at which point only the laser system can engage and begin material removal. This system can then disengage once lifted from the surface. The enclosed box can have a removal system for removing debris within the safety enclosed box.

[0067] In another embodiment, during autonomous indexed operation of the system, RF proximity localization technology along with GPS tracking of current and target locations can be employed to correct the roll cart’s trajectory and motion. Other automated features including but not limited to the use of edge detection technology may be employed to determine when the roll cart has reached the end of a bridge to prevent it from falling off.

[0068] In another embodiment, where there is excess moisture build-up on the surface of the I-beam that would prevent successful grinding and / or welding, the system may be provided with appropriate moisture detection sensors to allow for feedback to be provided to the operator on the usability of the various tools, if any them, during the day of operation.

[0069] In another embodiment, for autonomous operation modes, machine vision techniques such as CMOS visual light-based camera and / or infrared camera and / or lidar or scanning lidars can be used to scan over the weld sites after grinding. This will detect and report to a computerized system whether the quality of a weld site grind meets specification. The system will make determinations through the use of AI, trained through neural networks with data on various ground weld sites and report the quality of the weld site grind to assure it meets specification as programmed into the system. As well, a similarly trained AI system could use data on ground weld sites to advise on tool selection for the grinder system. It can use visual images, scanning lidar sensors, other sensors, and training data to provide advice on tool selection. A conductivity testing apparatus could also be used for the assessment of pre-ground or post-ground site conductivity for additional validation of surface debris severity or resulting surface grind quality.

[0070] In another embodiment, an autonomous paint dispenser could be provided to apply paint marks on the I-beam based on the positions entered for the stud placement. This eliminates the need for an additional worker to place the paint marks down.

Examples

Embodiment Construction

[0020]The following disclosure is presented to provide an illustration of the general principles of the present invention and is not meant to limit, in any way, the inventive concepts contained herein. Moreover, the particular features described in this section can be used in combination with the other described features in each of the multitude of possible permutations and combinations contained herein.

[0021]All terms defined herein should be afforded their broadest possible interpretation, including any implied meanings as dictated by a reading of the specification as well as any words that a person having skill in the art and / or a dictionary, treatise, or similar authority would assign particular meaning. Further, it should be noted that, as recited in the specification and in the claims appended hereto, the singular forms “a,”“an,” and “the” include the plural referents unless otherwise stated. Additionally, the terms “comprises” and “comprising” when used herein specify that ce...

BACKGROUND

[0001] The present invention relates generally to grinding equipment used to grind surface residue from pre-defined weld sites on structural I-beams used in bridge and building construction, and in particular to a system that assists a worker in performing this grinding operation to reduce required physical effort and injuries associated with grinding, and to increase productivity.

[0002] In steel erection projects, for example, bridge and building construction, steel studs are typically manually placed onto the surfaces of steel beams into ceramic ferrules, and then are welded in place onto the beam, typically an I-beam. Concrete is poured over a corrugated deck pan connected to the beam. The concrete hardens around and engages the shear studs in a manner which allows the beam to become more resistant to bending.

[0003] In advance of welding, the pre-defined weld sites on the beam are preferably prepared by removing all surface contaminants and residue to help ensure the integrity of the welds. Often, these weld sites are marked for grinding using paint marking, for example. Presently, grinding of the weld site is accomplished by manual grinding the surface of the beam using a hand-held power grinding tool or deck saw. Unwanted surface contaminants and residue are removed by using the grinding tool to scrape the weld site from side to side until an area typically at least 1.5” square or larger is treated. For heavier debris, the worker may utilize angle grinders or various other power tools. This is a slow and arduous process requiring the worker to repeatedly bend over and apply force on the grinding tool at each of numerous welding sites. The slow speed of this process increases construction time and costs. This repetitive and physically demanding work leads many workers to suffer significant lower back and knee injuries due to repeated stress while bending over for long periods of time.

[0004] Attempts have been made to develop technology to remove pressure from the worker’s back while utilizing these tools, as the tools are heavy and require application of significant downward force during the grinding process. Significant sums are paid for compensating workers for injuries sustained while utilizing these tools, and many workers are left with permanent back injuries. Some of these efforts have involved fully automated grinding systems that are very large, heavy, expensive, and complex. Accordingly, such systems are complex to operate and require powerful equipment to lift and move them into place.

[0005] Accordingly, there is a need for an apparatus that will reduce stress on the operator, but is relatively lightweight, simple to operate, and is easily maneuverable without the use of heavy lifting equipment.SUMMARY

[0006] An apparatus to aid in grinding the surface of a steel beam at pre-marked target weld sites is disclosed. The apparatus is arranged to be situated on the surface of a corrugated deck pan aligned with the I-beam having a width and a longitudinal axis. The apparatus includes a rolling cart arranged to traverse the peaks and valleys of the corrugated deck pan as it moves parallel to the beam’s longitudinal axis. A support arm carried by the rolling cart provides a tool holder arranged to retain a hand-held grinding tool therein. A slidable rod assembly positioned on the rolling cart is coupled to the support arm to enable movement of the support arm between retracted and extended positions across the width of the beam. A hinged arm connected between the slidable rod assembly and the support arm pivots about a horizontal axis to enable movement of the support arm vertically between an upward position where the hand-held grinding tool is disengaged from the beam surface and a downward position where the hand-held grinding tool engages the target weld site for grinding.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a more complete understanding of the present invention, reference is made to the following detailed description of embodiments considered in conjunction with the accompanying drawings, in which:

[0008] FIG. 1 is a perspective view of a first embodiment of an assistive apparatus for a grinding tool positioned over a corrugated deck pan at a site of construction of a building or bridge;

[0009] FIG. 2 is a perspective view the first embodiment of the assistive apparatus for a grinding tool;

[0010] FIG. 3 is side elevational view of the first embodiment of the assistive apparatus for a grinding tool;

[0011] FIG. 4 is an image of a second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly in a straight, retracted, and disengaged position;

[0012] FIG. 5 is an image of the second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly in a straight, retracted, and engaged position on a weld site;

[0013] FIG. 6 is an image of the second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly disposed in a straight, extended, and disengaged position;

[0014] FIG. 7 is an image of the second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly disposed in a straight, extended, and engaged position on a weld site;

[0015] FIG. 8 is an image of the second embodiment assistive apparatus for a grinding tool illustrating the support arm assembly disposed in a rotated, extended, and disengaged position;

[0016] FIG. 9 is a perspective view of a third embodiment of the assistive apparatus for a grinding tool;

[0017] FIG. 10 is a perspective view of the third embodiment assistive apparatus for a grinding tool;

[0018] FIG. 11 is a partial perspective view of a portion of the third embodiment assistive apparatus for a grinding tool of FIGS. 9 and 10, showing a quick-release assembly; and,

[0019] FIG. 12 is second partial perspective view of a portion of the third embodiment assistive apparatus for a grinding tool of FIGS. 9 and 10, showing a quick-release assembly.DETAILED DESCRIPTION

[0020] The following disclosure is presented to provide an illustration of the general principles of the present invention and is not meant to limit, in any way, the inventive concepts contained herein. Moreover, the particular features described in this section can be used in combination with the other described features in each of the multitude of possible permutations and combinations contained herein.

[0021] All terms defined herein should be afforded their broadest possible interpretation, including any implied meanings as dictated by a reading of the specification as well as any words that a person having skill in the art and / or a dictionary, treatise, or similar authority would assign particular meaning. Further, it should be noted that, as recited in the specification and in the claims appended hereto, the singular forms “a,”“an,” and “the” include the plural referents unless otherwise stated. Additionally, the terms “comprises” and “comprising” when used herein specify that certain features are present in that embodiment but should not be interpreted to preclude the presence or addition of additional features, components, operations, and / or groups thereof.

[0022] The following disclosure is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of the invention. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In this description, relative terms such as "horizontal," "vertical," "up," "down," "top," "bottom," as well as derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including "inwardly" versus "outwardly," "longitudinal" versus "lateral" and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as "connected" and "interconnected," refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both moveable or rigid attachments or relationships, unless expressly described otherwise, and includes terms such as "directly" coupled, secured, etc. The term "operatively coupled" is such an attachment, coupling, or connection that allows the pertinent structures to operate as intended by virtue of that relationship.

[0023] Referring FIGS. 1-3, an assistive apparatus for a grinding tool is shown and is generally designated at 100 and includes a tool support assembly 112 having a tool mount 110, a sliding assembly 114, a turntable 116, and a roller undercarriage 118.

[0024] In FIG. 1, the grinding cart 100 is shown positioned on a corrugated deck pan 120 and adjacent a conventional steel I-beam 122. The deck pan 120 and I-beam 122 may be utilized in the construction of buildings and bridges. The deck pan 120 is formed of standard gauge metal decking such as 16-gauge, 18-gauge, and 20-gauge steel, and may comprise a variety of configurations. However, as best shown in FIG. 1, it is common for the deck pan to have an undulating structure having alternating peaks and valleys. The deck pan 120 is configured to hold poured concrete that eventually forms a floor for a building or a road bed for an elevated road surface. The I-beam 122 may include a planar top surface 124 and a longitudinal axis that runs perpendicular to the sequential peaks and valleys of the deck pan 120 positioned adjacent thereto. The I-beam 122 may include a plurality of target weld sites on the top surface 124 that must be prepared in advance of welding the shear studs thereto. The target weld sites may be equally spaced along the length of the I-beam. Some target weld sites may be positioned in a line along the length of the I-beam 122 located closer to the deck pan, and other target weld sites may be positioned along another line located further away from the deck pan120.

[0025] The grinding cart 100 may include a base 111, sized and shaped to support the other components, including the turntable 116, the tool mount 110, the tool support assembly 112, and the sliding assembly 114. The turntable 116 and sliding assembly 114 are also collectively referred to as a mount assembly, the purpose of which is to support and provide for movement of the tool mount 110.

[0026] A roller undercarriage 118 (also referred to more generally as running gear) is located beneath the base 111 and is shown positioned on the corrugated deck pan 120. The roller undercarriage 118 is adapted to enable the grinding cart 100 to be moved along the deck pan in a direction parallel to the length of the I-beam 122 (shown by Axis A in FIG. 2), to assist the worker in positioning a hand-held grinding tool 134 retained within the tool mount 110 over the target weld sites. As best shown in FIG. 3, in this embodiment, the roller undercarriage 118 comprises plurality of closely-spaced and parallel rollers 164 mounted to rails 162a and 162b positioned at opposite ends of the roller undercarriage 118.

[0027] Many other types of powered and unpowered running gear could be used in alternate embodiments. For example, and as shown in FIGS. 4 through 8, an electric track drive system could be used, comprising two rubber tracks driven by a DC motor which is powered by least one battery. An electric motor powered rubber track system is particularly suitable for this application because it provides stability as the mobile platform moves across the undulations of the corrugated deck pan and because generators are commonly available on job sites in which the mobile platform is used. Other embodiments, different types of ground-engaging elements could be used, such as rollers, tracks (rubber, rigid plastic, or metal), and wheels. In addition, any suitable means for powering the running gear could be used, such as other types of electric motors, petroleum-powered engines, and fluid-driven pumps. In embodiments in which the running gear is powered, movement of the running gear may be controlled from the handlebars 146 located on the tool support assembly 112.

[0028] The tool mount 110 may include a collar 136 through which the hand-held grinding tool 134 may be disposed, and a support plate 138 to retain the collar 136 against the tool support assembly 112. Once retained within the tool mount 110, the grinding tool may be plugged into a conventional AC outlet available on the jobsite for grinding.

[0029] Referring now to FIGS. 9-12, in an alternative embodiment, the tool mount 310 is shown as including a collar 336, a support plate 338, and a thumb screw. The collar 336 may include a central opening through which the grinding tool 134 may be disposed and may include captive screws to retain the grinding tool 134 therein. By loosening the thumb screw, the collar 336, with the grinding tool 134 retained therein, may be quickly released from the support plate 338 without the need for special tools. In this manner, the tool mount 310 provides the ability quickly exchange different grinding tools onto the grinding cart 100 based upon the surface residue encountered on the I-beam 122 or to replace worn out grinding wheels and blades. In an alternative implementation, the tool mount 110 could be adapted to permanently retain a dedicated grinding tool.

[0030] In the embodiments shown herein, the grinding tool is a rotary grinder. In other embodiments, the tool mount 110 could be adapted to removably retain other types of abrasive tools, such as drum-based surface conditioning tool, a belt sander, an orbital sander, an oscillating tool with an abrasive attachment. In yet other embodiments, a permanent, built-in abrasive tool could be provided in place of the tool mount 110.

[0031] The tool assembly may include a telescoping handle 144 and handlebars 146 extending horizontally therefrom. The telescoping handle 144 may be provided in separate parts such that a first part moves or slides in and out with respect to a second part to adjust the length of the handle 144 and height of the handlebars 146. The handle 144 may include a plurality of equidistantly spaced through-holes to fix the handlebars 146 at a suitable height to enable a worker to remain standing in an upright position during grinding. As shown in FIGS. 1-3, the handlebars 146 may bend at a slight angle and may include handgrips at each end. The tool support assembly 112 is adapted to enable the user to perform a grinding operation and move the grinding tool to the next weld site without bending over.

[0032] Referring now to FIG. 2, the tool support assembly 112 may be attached to a frame 142 through a hinged arm 140 having pins located at its opposite ends. The pins enable pivotal movement of the hinged arm 140 about axes C and D to enable movement of the tool support assembly 112 from an upward position (see FIG. 4) where the grinding tool 134 is disengaged from the target weld site on the I-beam 122 to a downward position (as shown in FIG. 2) where the grinding tool 134 engages the target weld site for removal of surface contamination therefrom.

[0033] When performing a grinding operation, the worker may apply a downward force on the handlebars 146, causing the tool support assembly 112 to move from the upper position to the lower position. Preferably the range of motion provided by the tool support assembly 112 is sufficient to enable an abrasive element (such as a grinding disk) of the grinding tool 134 to extend below the running gear when the lower position. This ensures that the grinding tool 134 is able to grind weld spots in a variety of job site environments. The range of motion preferably enables the grinding tool 134 to be positioned well above the i-beam 122 when in the upper position, to provide clearance during movement of the grinding cart 100, as well as to facilitate maintenance and replacement of the grinding tool 134.

[0034] The tool support assembly 112 may be provided with a tensioning spring 166, also shown at 266 in FIGS. 4 through 8, to apply a biasing force against this downward force. In this manner, the upward force needed by the worker to lift the grinding tool 134 from the target weld site is lessened due to assistance provided by the tensioning spring 166. This also will cause the tool support assembly 112 to return to the upper position when released. In other words, the support assembly 112 is biased into the upper position by the tensioning spring 166.

[0035] As best shown in FIGS. 4-8 of the second embodiment, the tensioning spring 266 may be connected between a spring plate 268 and a support plate 238 of the tool mount 210. The tensioning spring 266 may be adjustable to adjust the amount of biasing force where grinding tools of different weights are utilized. Alternatively, multiple alternative tensioning springs may be provided based upon the weight of the grinding tool employed and the amount of biasing force required. In other embodiments, other types of linear force elements could be substituted for the spring, such as a gas cylinder, elastomeric rubber strap, or flexible leaf spring element.

[0036] The tool support assembly 112 may attach to the sliding assembly 114 through the hinged arm 140 and the frame 142. The sliding assembly 114 may include a plurality of rods 150a, 150b, and 150c, each rod extending through a corresponding rod gliders 152a, 152b, and 152c, the rod gliders mounted to the turntable 116. At their distal ends, the rods 150a, 150b, and 150c connect to a rod block 148c. The rods 150a, 150b, and 150c extend through openings in a rod block 148b and are attached at their proximal ends to a rod block 148a. The rod blocks 148a and 148b may be mounted to the frame 142 in a spaced-apart relationship. As the worker pushes forward or pulls back on the handlebars 146, the rods 150a, 150b, and 150c travel through the rod gliders 152a, 152b, and 152c along an axis 2 (FIG. 2 ) from a retracted position to an extended position. In this manner, the worker can position the grinding tool 134 at desired locations between these positions to reach target weld sites on the I-beam 122 positioned at locations closer to and further away from the deck pan 120. Once the worker applies a downward force on the handlebars 146 to engage the grinding tool 134 with the target weld site, the handlebars 146 may be utilized to move the grinding tool 134 back and forth between the extended and retracted positions for effective grinding.

[0037] The worker can also apply a lateral force to the handlebars 146 to rotate the turntable 116 in either a clockwise or counterclockwise direction to adjust the position of the grinding tool 134 along an arc to reach desired locations of target weld sites. Once engaged with the target weld site, in addition to moving the grinding tool 134 in the back-and-forth directions, the worker can apply lateral forces to the handlebars 146 to rotate the grinding tool 134 along an arc to grind out a substantial surface area of the target weld site without needing to move the grinding cart 100. The turntable 116 may optionally include a pin, other structure, to selectively lock rotation of the turntable 116.

[0038] In one embodiment, the sliding assembly 114 may include a motor assembly coupled to a gear assembly to control sliding movement of the rods 150a, 150b, and 150c through the rod gliders 152a, 152b, and 152c to reduce the amount of effort required by the worker.

[0039] The sliding assembly 114 may include an electrical or mechanical braking system responsive to worker actuation to apply a braking force to the rods 150a, 150b, 150c to retain the grinding tool 134 in a particular extended or retracted position. The braking force may be a compressive force applied in a normal direction to opposite sides of the rods 150a, 150b, 150c. Optionally, the braking system may continually apply a braking force onto the rods 150a, 150b, and 150c, and only in response to the worker actuating a button, such as located on the handlebars 146, will the braking force be released. A signal may be sent to actuate an electrical solenoid or mechanical component to release the brake. By utilizing the brake, the worker can easily move the head of the grinder tool to a target weld site.

[0040] Referring now to FIGS. 4-8, a second exemplary implementation of a grinding cart 200 is shown. It should be understood that elements of grinding cart 200 that are shared with the first embodiment (grinding cart 100) are represented by reference numerals increased by a factor of 100. For example, the tool support assembly 112 of the grinding cart 100 corresponds to the tool support assembly 212 of the grinding cart 200. In the interest of clarity, some features of this embodiment that are shared with the first embodiment are numbered in FIGS. 4-7, but are not repeated in the specification.

[0041] In FIG. 4, the worker has moved the tool support assembly 212 to a retracted and upward / disengaged position such that the head of the grinding tool 234 is positioned over but not in contact with a target weld site located on the I-beam 222 at a position closer to the corrugated deck pan 220. In FIG. 5, the worker has applied a downward force to the handlebars 246, moves the tool support assembly 212 into a downward / engaged position, which enables the grinding tool 234 to grind that target weld site. In FIG. 6, the worker has moved the tool support assembly 212 to an extended and disengaged position such that the head of the grinding tool 234 is positioned above but not in contact a target weld site located on the I-beam 222 at a distance further from the corrugated deck pan 120. In FIG. 7, the worker has applied a downward force to the handlebars 246 to grind that target weld site. In FIG. 8, the worker has applied a lateral force to the handlebars 246 resulting in a counterclockwise rotation of the tool support assembly 212 for grinding another target weld site.

[0042] FIGS. 9 - 12 illustrate a third exemplary implementation of a grinding cart 300. It should be understood that elements of grinding cart 300 that are shared with the first and / or second embodiments (grinding carts 100 and 200) are represented by reference numerals increased by a factor of 100 or 200 (respectively). For example, the tool support assembly 212 of the grinding cart 200 corresponds to the tool support assembly 312 of the grinding cart 300. In the interest of clarity, some features of this embodiment that are shared with the first or second embodiment are numbered in FIGS. 9 through 12, but are not repeated in the specification.

[0043] One advantage of the grinding cart 300 is that the sliding assembly 314 is sufficiently elevated above the turntable arranged to be positioned a sufficient distance above the turntable 358 so as to enable a full 360-degree unobstructed rotation of the sliding assembly 314. This expands the ability of the grinding tool 334 to reach more target weld sites on the I-beam 122 as well as on I-beams located adjacent thereto without moving engaging the drive assembly of the grinding cart 300.

[0044] Movement of the sliding assembly 314 is controlled by a ball gear drive system 376. The ball gear drive system 376 is preferably controlled by a two-way temporary switch (not shown) located on the handlebars 346 that enables the user to selectively extend or retract the sliding assembly 314. The ball gear drive system 376 prevents the ball gear drive system 376 from extending or retracting when it isn’t energized, which eliminates the need for a separate braking system.

[0045] Referring to FIGS. 11 and 12, the tool mount 310 is shown in greater detail. In this exemplary embodiment, a quick-release plate 378 is releasably affixed to the support plate 338 by a pair of bolts 380a. 380b. When the thumb screw 382 is tightened, the bolts 380a, 380b hold the quick-release plate 378 in place with a friction fit. When a tool change is desired, the user loosens the thumb screw 382, which loosens the bolts 380a, 380b and allows the quick-release plate 378 to be moved downwardly. This results in the bolt 380a disengaging an upper slot 384 and the bolt 380b to move to an enlarged portion 386 of a lower slot 388, which enables the quick-release plate 378 to be removed from the support plate 338.

[0046] In an embodiment, a pedal may be placed near the end of the head of the grinding tool to align the grinding tool head over the target weld site as well as to enable the application of force that may be required in addition to the force applied through the handlebars by the operator’s upper body. Because the pedal would be placed in proximity to the head of the grinding tool, it may be necessary to provide a protective shield for the operator’s foot and lower leg in the event of a malfunction of the grinding tool or its blade while using the assistive apparatus. The shield may be formed of any suitable metallic or rigid plastic material typically used for such applications, e.g., a polycarbonate.

[0047] In an embodiment, the grinding cart 100 may be fitted with a lifting jack at one end that may be controlled through an operator interface for the purpose of lifting and transporting heavy materials on the jobsite through use of the motorized capabilities of the grinding cart 100.

[0048] In another embodiment, the grinding cart 100 may be sized to fit within the dimensions of a standard doorway width so that the grinding cart 100 can be utilized for grinding surface residue on floors such as concrete in buildings and scraping carpet up inside.

[0049] In another embodiment, the grinding cart 100 provides for autonomous operation in that an operator can move the entire grinding cart 100 through the use of additional operator controls placed on the handlebars 146 to control a motorized conveyor system to move the grinding cart 100 in any desired direction. This conveyor system will include two separate sides with a separate motor and gearbox for each side that will be connected to a controller. The output of the gearboxes will drive a sprocket that connects to a belt of frictional rubber-like material for movement on a variety of surfaces but in most cases on the top surface of the corrugated deck pan which is galvanized stainless steel. During the operation of the grinding cart 100, the direction will be parallel to the length of the I-beam surface 124 which would also be parallel to the path of travel on the resulting road surface. The controls would allow for adjustment of speed as well as the ability to rotate and to move backward and forward along the length of the I-beam surface. The system can move at a variety of speeds as indicated by operator controls that can approach human walking speeds.

[0050] In another embodiment, the grinding cart 100 may include an automated indexing feature allowing for pre-programmed spacing and timing to allow for the cart to be programmed to move in predetermined distances in predetermined durations of time. This functionality would enable the operator to relinquish control of motion of the cart and focus solely upon using the grinding tool to grind the target weld sites on the I-beam. During autonomous operations, the system may have the ability to auto-detect obstacles using, for example, a SICK safety scanning lidar for detection and registration of obstacles that would impede the motion of the cart. This would prevent unwanted collisions with disregarded materials and debris on the jobsite as well as workers walking in the motion path of the system. During autonomous operation of the grinding cart 100, a lidar system, possibly 2D, could be used to scan the surface to detect proximity to the end lip of the corrugated deck pan to correct for alignment to prevent the grinding cart 100 from moving off the deck pan 120 and onto the surface of the I-beam beam 122. The motorized track system provides the ability to move off of the deck pan onto the beam surface or vice versa. The motorized track system also enables motion of the grinding cart 100 across a variety of surfaces on the construction site to reach a destination where a road surface or similar flat surface may not be readily available.

[0051] In another embodiment, the motion of the operator during the rotation and retraction / extension can be assisted or fully automated through motorized enhancements. This can be accomplished for the extended and retracted movement by placement of a linear actuators controlled through a motor linked to various buttons located on the operator’s handle interface to enable the operator to easily extend or retract the rods 150a, 150b, and 150c. This actuator could be a ball-screw drive to eliminate the need for an electrically or mechanically actuated brake system. It could also be a conventional belt drive or similar actuator. Alternatively, movement of the turntable 116 could be accomplished through an actuable button disposed on the handlebar interface to effect clockwise or counterclockwise rotation of the turntable enabling the operator to apply minimal force to rotate the turntable. This could be performed through an electrical motor system coupled to a gearing system connected to the turntable with a toothed gear exterior.

[0052] In another embodiment, the grinding cart 100 may include an additional set of rods 150a, 150b, and 150c that would be controlled in the same manner as described above. This set of rods would run perpendicular to the original set used for extensions / retraction movement to allow for an X-Y Cartesian motion. This secondary set of rods would provide for motion of the grinding tool in a direction parallel to the length of the beam and could be controlled through a similarly actuated mechanical or electrical braking system, or alternatively, through an electrically assisted motion as described with the extension / retraction rods through operator switch controls on the handlebar interface. Additionally, the use of linear sliding rails could be replaced entirely with purely linear actuators.

[0053] In another embodiment, the indexing motion feature could be expanded to the motion of these two perpendicular motorized assisted rod systems. The grinding cart 100 could move to the appropriate indexed position and wait for the operator to perform the grinding operation before moving to the next position as indicated through an operator input command or through a sensor detecting quality of surface residue.

[0054] Additionally, wireless controls can be provided to transmit information to a controller computer on the grinding cart 100 instead of requiring hard-wired connections for controlling the various operator controls of the grinding cart 100. This wireless system will consist of an operator handle box powered through a DC battery and RF link coupled to a compatible RF device in the control box directly mounted on the cart. This will eliminate the need for hard wiring and will prevent cable damage resulting from rotational and translational movement of the grinding cart 100 during use. The RF controls could also be embedded in a controller entirely off of the grinding cart 100 to allow a second worker not performing the grinding to move the grinding cart 100 through the controls just as the grinding tool operator could.

[0055] In a motorized embodiment, the grinding cart 100 can connect to an AC power source used to distribute power to the grinding tool as well as to the locomotion and control systems. The AC power source can also be used to charge a DC battery. The DC battery could be used to power to the grinding tool as well as to the locomotion and control systems. Alternatively, the grinding cart 100 could be adapted to only power the grinding tool through AC power.

[0056] In another embodiment, the rolling cart may be provided with rubber material treads, the treads being wider than the valleys of the corrugated deck pan such that the rolling cart will not get caught in the valleys of the corrugated deck pan when in any direction over the corrugated deck pan.

[0057] In another embodiment, during the autonomous operation, the operator may want to halt system operation as it moves from indexed grind row to row, or from grind spot to grind spot. The operator may want to halt autonomous operation temporarily for safety reasons, to use the manual or manually-assisted controls, or to return to inadequately ground locations. The operator interface on the handlebar provides an actuator that can be depressed, or data entered when the operator wishes to halt system operation. The system may also be provided with an auditory or a hand-motion detection system enabling the operator halt a pre-programmed routine using auditory or hand-motion commands.

[0058] In another embodiment, a button may be provided on the handlebar interface for moving from one row of target weld sites to the next instead of employing the pre-programmed timing and spacing for the system and needing to fit into the time constraints which may not always be realistic as the operator requires breaks.

[0059] In another embodiment, during autonomous operation mode, a visual CMOS camera could be used to detect paint marks placed on the beam surface to represent the rows of target weld sites. This visual recognition can occur through machine vision object recognition techniques or possibly through the use of an AI system trained with a neural network with information on the expected paint markings. These paint markings can then be coordinated through a localized coordinate system to place the grinding tool head directly in line with the rows of target weld sites. The operator would then engage the grinds through retraction and extension of the tool support assembly 112. This would provide visual feedback for grinding tool placement on the system with the motion being able to be automated based on machine vision.

[0060] In another embodiment, the grinding cart 100 may collect data from various sensors throughout the operation period. This data could be time stamped and could include visual images, lidar data, operator inputs, safety warnings, motor actuation with respective encoder data, and motor positions for the rods used for the operator placement over the target grind areas. The data could be used to compute analytics relating to average grind times and grind efficiency, and for future AI training purposes.

[0061] In another embodiment, the grinding cart 100 may include surface restoring tools such as a debris removal blower or vacuum system to remove loose debris from the cleanly ground sites. This surface residue is commonly removed to prevent defective welds. Currently, workers use a leaf blower or shop vacuum to remove such surface residue and debris after grinding.

[0062] In another embodiment, an exoskeleton to assist in tool lifting could be used in combination with the grinding cart 100 to ease lifting. This exoskeleton can be worn by the operator to remove pressure from commonly stressed points like the lower back and hips by transferring weight into a belt-like harness. As well, a zero-gravity style assist can also be mounted onto the cart for similar purposes of easing lifting of tools.

[0063] In another embodiment, tool holders may be provided to enable changing out of a variety of available tools throughout a workday. These tool holder holders would permit the operator to easily swap an existing tool holder for one holding a needed tool as judged by the operator’s perception of the quality of the ground surface. The tool holder is intended to enable the interchangeability of the end tool depending on the degree of severity and type of surface residue. This could also be used in high-rise building construction, on decks of aircraft carriers for stud welding, and many others. Other tools could include but are not limited to chippers and scrappers.

[0064] In another embodiment, multiple grinding tools may be attached at the same time with adjustability for spacing between the grinding tools for purposes of grinding multiple rows of target weld sites simultaneously with a singular applied motion of the operator. The multiple grinding tools could also be used to grind away multiple grind spots on a single row simultaneously. A grinding tool such as a commercially available bench top grinder may be employed with its abrasive stone being applied to the target weld site with necessary modifications from the traditional use case. A single rotating shaft may be used with several grinding tool heads simultaneously that can be the same or vary in composition.

[0065] In another embodiment, surface residue can be detected through a laser system that produces a beam of a known radiance and then measures the radiance received back compared with an expected standard of reflection radiance.

[0066] In another embodiment, along with the aforementioned tools, a laser removal system may be used to remove surface debris. This system may include a point laser with a wavelength known to remove debris present on a target surface connected in a safety proofed enclosed box that gets lowered flush onto the surface and has the laser attached on an XY motion system that will move the laser point across the target weld location in an automated fashion. Sensors can be built into the enclosed box to contact the ground surface and engage magnets for purposes of more safely affixing the system onto the surface of interest at which point only the laser system can engage and begin material removal. This system can then disengage once lifted from the surface. The enclosed box can have a removal system for removing debris within the safety enclosed box.

[0067] In another embodiment, during autonomous indexed operation of the system, RF proximity localization technology along with GPS tracking of current and target locations can be employed to correct the roll cart’s trajectory and motion. Other automated features including but not limited to the use of edge detection technology may be employed to determine when the roll cart has reached the end of a bridge to prevent it from falling off.

[0068] In another embodiment, where there is excess moisture build-up on the surface of the I-beam that would prevent successful grinding and / or welding, the system may be provided with appropriate moisture detection sensors to allow for feedback to be provided to the operator on the usability of the various tools, if any them, during the day of operation.

[0069] In another embodiment, for autonomous operation modes, machine vision techniques such as CMOS visual light-based camera and / or infrared camera and / or lidar or scanning lidars can be used to scan over the weld sites after grinding. This will detect and report to a computerized system whether the quality of a weld site grind meets specification. The system will make determinations through the use of AI, trained through neural networks with data on various ground weld sites and report the quality of the weld site grind to assure it meets specification as programmed into the system. As well, a similarly trained AI system could use data on ground weld sites to advise on tool selection for the grinder system. It can use visual images, scanning lidar sensors, other sensors, and training data to provide advice on tool selection. A conductivity testing apparatus could also be used for the assessment of pre-ground or post-ground site conductivity for additional validation of surface debris severity or resulting surface grind quality.

[0070] In another embodiment, an autonomous paint dispenser could be provided to apply paint marks on the I-beam based on the positions entered for the stud placement. This eliminates the need for an additional worker to place the paint marks down.

Examples

Embodiment Construction

[0020]The following disclosure is presented to provide an illustration of the general principles of the present invention and is not meant to limit, in any way, the inventive concepts contained herein. Moreover, the particular features described in this section can be used in combination with the other described features in each of the multitude of possible permutations and combinations contained herein.

[0021]All terms defined herein should be afforded their broadest possible interpretation, including any implied meanings as dictated by a reading of the specification as well as any words that a person having skill in the art and / or a dictionary, treatise, or similar authority would assign particular meaning. Further, it should be noted that, as recited in the specification and in the claims appended hereto, the singular forms “a,”“an,” and “the” include the plural referents unless otherwise stated. Additionally, the terms “comprises” and “comprising” when used herein specify that ce...

Claims

1. A mobile platform for grinding a plurality of weld sites on a metal surface, the mobile platform comprising:a base;a running gear secured to the base, the running gear adapted to enable movement of the base at least along a longitudinal axis;a tool support assembly comprising at least one control handle, a tool mount, and a mount engaging arm, the tool mount comprising an abrasive tool or a tool mount that is adapted to removably secure an abrasive tool, the abrasive tool having an abrasive element; anda mount assembly having a base engaging portion attached to the base, the mount assembly being attached to the tool support by the mount engaging arm;wherein the tool support assembly is adapted to enable the tool mount to move in a range of motion between an upper position and a lower position; andwherein the abrasive element is positioned lower relative to the running gear when the tool mount is in the lower position than when the tool mount is in the upper position.

2. The mobile platform of claim 1, wherein the running gear is unpowered.

3. The mobile platform of claim 1, wherein the running gear is driven by an electric motor.

4. The mobile platform of claim 3, wherein the running gear comprises at least two rubber tracks.

5. The mobile platform of claim 1, wherein the abrasive element is positioned below the running gear when the tool mount is in the lower position.

6. The mobile platform of claim 1, wherein the mount engaging is pivotally attached to the mount assembly.

7. The mobile platform of claim 6, further comprising a linear force element adapted to bias the tool mount into the upper position.

8. The mobile platform of claim 1, wherein the mount assembly is adapted to rotate the tool support assembly relative to the base.

9. The mobile platform of claim 8, wherein the mount assembly is adapted to enable 360 degree rotations of the tool support assembly relative to the base.

10. The mobile platform of claim 1, wherein the mount assembly comprises a sliding assembly that enables the tool support assembly to be moved between an extended position and a retracted position, wherein the tool mount is positioned closer to the base in the retracted position than in the extended position.

11. The mobile platform of claim 10, wherein the sliding assembly comprises at least one sliding rod slidably retained within a rod glider.

12. The mobile platform of claim 10, wherein the sliding assembly includes a braking system adapted to selectively apply a braking force that, when applied, prevents movement of the tool mount between the retracted position and the extended position.

13. The mobile platform of claim 12, wherein at least one handle bar includes an actuator adapted to selectively engage and disengage the braking force.

14. The mobile platform of claim 1, further comprising at least one battery and a DC motor that selectively drives the running gear.

15. The mobile platform of claim 14, further comprising a drive controller that is adapted to control movement of the running gear based on operator controls located on the at least one control handle.

16. The mobile platform of claim 1, wherein the abrasive tool is a rotary grinder.

17. An apparatus to assist a worker in grinding residue from a target weld site on a beam using a hand-held grinding tool while traversing a corrugated deck pan having sequential peaks and valleys aligned with the beam, the beam having a surface, a width and a longitudinal axis, the apparatus comprising:a rolling cart operably configured to traverse the peaks and valleys of the corrugated deck pan in a direction parallel to beam longitudinal axis;a tool holder for retaining therein the hand-held grinding tool;a support arm for retaining the tool holder; and,a slidable rod assembly positioned over the rolling cart, the support arm connected to the slidable rod assembly through a hinged arm, the slidable rod assembly configured to enable movement of the support arm horizontally between a retracted position and an extended position over the width of the beam surface, the hinged arm configured to pivot about a horizontal axis enabling movement of the support arm vertically between an upward position wherein the hand-held grinding tool is disengaged from the beam surface and a downward position where the hand-held grinding tool engages the beam surface at the target weld site for grinding.

18. A method for grinding residue from a target weld site located on the surface of a beam utilizing a hand-held grinding tool, the beam having a width and a longitudinal axis, the method comprising:a. providing a mobile cart having a tool support assembly coupled thereto, the tool support assembly movable horizontally between retracted and extended positions over the width of the beam and movable vertically between upward and downward positions, the tool support assembly including a tool mount connected thereto for retaining the hand-held grinding tool therein;b. placing a hand-held grinding tool into the tool mount;c. providing power to the hand-held grinding tool;d. instructing the mobile cart to traverse the peaks and valleys of a corrugated deck pan aligned with the beam in a direction parallel to the beam longitudinal axis to a target weld site;e. moving the tool support assembly horizontally to locate the hand-held grinding tool over the target weld site; and,f. moving the tool support assembly vertically downwardly to engage the hand-held grinding tool on the target weld site; and,g. grinding the target weld site of the beam to remove residue.

19. The method of claim 18, further comprising mounting a turntable to the mobile cart and coupling the tool support assembly to the turntable to enable rotational movement of the tool support assembly in clockwise and counterclockwise directions.

20. The method of claim 18, further comprising providing handlebars on the tool support assembly to enable movement of the tool support assembly between the retracted and extended positions, and between the upward and downward positions.

Images