Patent Application
20210001720
Not applicable
Not applicable
The present invention relates to equipment used to prepare a floor for refinishing. More specifically, the present invention relates to such equipment that is self-propelled and steerable.
Various types of devices are employed to prepare a floor for refinishing. This includes machines designed to scrape tile and carpet from a floor, polishers, grinders, burnishers and shot blasters. National Flooring Equipment, Inc. of Minneapolis, Minn., has been a leading manufacturer and distributor of floor preparation equipment for sixty years.
Many concrete floors in commercial building and residential garages are finished with epoxy coatings. Over time resurfacing is required. The original surface must be roughened up to permit the new layer of epoxy to properly adhere to the floor. This step of roughening the floor may be performed using a grinder or a shot blaster.
A shot blaster is designed to blast small metal pellets (shot) onto the floor's surface. Shot blasters typically include a reservoir containing a supply of shot, a mechanism for metering the delivery of the shot, an impeller that provides the force to blast the metered shot at the floor, and a powerful vacuum that collects the used shot, as well as the dust and debris generated by the shot blasting processes. National Flooring Equipment offers a series of shot blasters of different sizes and configurations. These include the National HB5 handheld shot blaster, the National A30 self-propelled shot blaster, and the National A12 ride-on shot blaster.
While all shot blasters offered by National are of high quality and effectively treat the floor, National is continually trying to improve its equipment offerings.
The present invention provides various ergonomic improvements to the steering mechanisms for self-propelled shot blasters and other types of self-propelled floor preparation equipment. These improvements are directed to an ergonomic controller for controlling and steering the machine.
More specifically, the ergonomic controller comprises a mount, a joint and a control stick. The ergonomic controller may also include a height-adjustable column.
The mount is essentially a plate including a first handle and a channel, and a hub positioned and mounted within the channel. The hub is adapted to rotate about a first axis of rotation substantially perpendicular to the plate. The first handle may be an opening through the plate. An additional opening through the plate may be present to provide a second handle.
The joint may take several forms such as a hinge, a double hinge, or a ball joint. A single hinge allows rotation along a single axis of rotation. A double hinge allows rotation along two independent axes of rotation that are typically perpendicular to each other. A ball joint allows even greater flexibility of adjustment. In most cases, the joint has a first member coupled to a machine and a second member coupled to the mount. The joint also has at least one pivot member, e.g., a pin of a hinge or a ball of a ball joint. The pivot member allows the second member of the joint to be pivoted relative to the first member. The joint also includes a first lock. The lock is adapted to be loosened to permit the second member and attached mount to be pivoted relative to the first member and the machine. The lock is also adapted to be tightened to selectively fix the second member and mount in place at a selected orientation relative to the first member and machine.
The control stick, itself, is mounted to and extends from the hub. As such, the hub permits the control stick to rotate along the first axis of rotation either separately or along with the hub.
As noted above, the ergonomic controller may further comprise a height adjustable column. The height adjustable column is disposed between the first member of the joint and the rest of the machine. The height adjustable column has at least two sections that are adapted to telescope with respect to each other such that the length of the column is adjustable. A second lock is provided to selectively fix the length of the height adjustable column.
As should be clear from the foregoing, the height of the control stick is adjusted via the height adjustable column. At least the pitch of the control stick is adjustable using the joint. Depending on the joint used, the roll of the control stick may also be adjustable. The yaw of the control stick is adjustable by rotating the control stick about the first axis of rotation.
Those skilled in the art will understand that self-propelled shot blasting machines often have a steerable drive wheel driven by a first electric motor, a second electric motor driving a blast wheel, a hopper containing a supply of shot, a valve for metering shot from the hopper to the blast wheel, and a plenum coupled to a vacuum. The control stick of the ergonomic controller described above allows for one-handed control of at least the first electric motor and, thus, the speed and direction of travel of the machine. The control stick will typically include switches that may be manipulated to control speed and direction (forward or reverse) of the machine. Either the handles or the control stick may be grasped and used to steer the machine in a controlled manner.
The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts:
This description of the preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top” and “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 drawings under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a specific orientation. Terms such as “connected”, “connecting”, “attached”, “attaching”, “join” and “joining” are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece, unless expressively described otherwise.
A self-propelled shot blasting machine 1 is shown in
Machine 1 is driven by an electric motor 14 coupled to drive wheel 12. The machine 12 has a second motor 16 that drive a blast wheel (not shown).
The machine 1 also has a plenum 20 incorporating a hopper 22. The plenum 20 is coupled to a vacuum (not shown) by a vacuum tube 24.
Hopper 22 is filled with shot prior to use. The vacuum is then energized to create air flow through the plenum 20. The motors 14 and 16 are then energized. Energizing motor 16 causes the shot wheel to spin. Shot is metered from hopper 22 through a valve 23 to the shot wheel which accelerates the shot toward the floor in an area confined by a suction head 26. As the shot impacts the floor's surface, that surface is roughened. The shot, floor debris and dust are carried through the plenum 20 by the air flow. The dust and debris are carried to a collection bag (not shown) by the vacuum. The shot is deposited back into the hopper 22 and reused. Operation of at least motor 14 is controlled by ergonomic controller 30. As shown, the ergonomic controller 30 comprises a mount 32, joint 34, control stick 36, a guard rail 38 and a height adjustable column (mounting bar) 40.
One such mount 32 is shown in greater detail in
The joint 34 comprises a first member 60 coupled to the machine 1 via the height adjustable column (adjustable mounting bar) 40. The joint 34 further comprises a second member 62 coupled to the mount 32. The joint 34 also includes a pivot member 64. The pivot member 64 shown is a pin coupled to the first member 60 and having a threaded end 66 extending through an opening in the second member 62. The second member 62 is adapted to rotate about the pivot member 64.
The joint 34 also comprises a first lock 68. As shown, the first lock 68 comprises a locking knob that has a threaded opening 69 adapted to be coupled with the threaded end 66 of pivot member 64. When the first lock 68 comprises such a locking knob, the lock 68 is released by turning the locking knob in a first direction thereby loosened the locking knob and permitting the second member 62 and the mount 32 to be pivoted about pivot member 64 relative to the first member 60, the height adjustable column (adjustable mount bar) 40 and the machine 1. When the mount 32 is in a desired preselected position, lock 68 is engaged by turning the locking knob in a second direction to tighten the locking knob. Engaging the lock 68 by tightening the lock knob serves to selectively fix the second member 62 and the mount 32 in place in the selected position relative to the first member 60, the height adjustable column (adjustable mount bar) 40 and the machine 1.
As shown in
One skilled in the art should recognize that the rotatable connection between the control stick 36 and the mount 32 permit the yaw of the control stick 36 to be adjusted. Further, the joint 34 shown allows the pitch of the control stick 36 to be adjusted. When the pivot member 64 is a pin, this is achieved by orienting the pin so that the pin extends along a second axis of rotation perpendicular to the first axis of rotation 52. If a ball joint or a double hinge joint is employed as the joint 34, the roll of the control stick 36 is also adjustable.
Height adjustment is provided by the height adjustable column (adjustable mounting bar) 40. As shown in
Each of the telescoping sections 80/82 has a set of holes 84 along its length. The overall length of the height adjustable column (mounting bar) 40 is adjusted by telescoping the telescoping sections 80 and 82 relative to each other. A second lock 86 may be employed to secure the two sections 80 and 82 to fix the length of the height adjustable column (adjustable mounting bar) 40 as a selected length. This second lock 86 may be as simple as a locking pin extending through aligned holes in the sections 80 and 82.
All the adjustment features referenced above may be employed separately or in any combination together. When all are employed, the yaw, pitch, roll and height of the control stick 36 are all adjustable.
The drawings further show a guard 38 extending from the mount adjacent the control stick 36. Guard 38 includes a first leg 87 and a second leg 88 extend perpendicularly from the top of plate 42. The two legs 87 and 88 are joined together by a curved section 89. When in use, the operator's hand is positioned between the control stick 36 and the guard 38 such that the guard provides some level of protection for the hand if the guard engages some other object during operation of the machine. The guard 38 protects the control stick in the similar fashion.
As shown in
This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.
