This application is a non-provisional of U.S. Application Ser. No. 62/627,002 filed Feb. 6, 2018, which is incorporated herein by reference.
Commercial mowers, such as those often used for maintaining golf courses, for example, typically use reel-type mowing units which employ cylindrical cutting reels having a number of helical blades disposed about a central shaft. To maintain optimal cutting performance, the helical blades of the cutting reels must be regularly sharpened.
The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain principles of embodiments. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.
In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
It is to be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless specifically noted otherwise.
Commercial mowers, such as those often used for maintaining golf courses, for example, typically use reel-type mowing units which employ cylindrical cutting reels having a number of helical blades disposed about a central shaft. To maintain optimal cutting performance, the helical blades of the cutting reels must be regularly sharpened, preferably as close as possible to OEM (original equipment manufacturer) specifications. In view of the above, grinding systems have been developed to sharpen helical cutting blades of such mowing units.
Because of the helical design of blades 22, while mowing, grass clippings are pushed toward one end of the cylindrical cutting reel such that blade wear is uneven, with the wear increasing from one end the other such that, over time, the perimeter surface 21 of cutting reel 20 may assume a conical shape rather than a cylindrical shape.
One type of grinding process is referred to as a “touch-off” grinding process. Typically, during “touch-off” grinding, a shaft of a grinding wheel used to sharpen cutting reel 20 is adjusted to be parallel with perimeter surface 21 of cutting reel 20. According to such process, the grinding wheel is first positioned at a first end of cutting reel 21, and grinding wheel shaft is adjusted until the grinding wheel touches the perimeter surface 21 of cutting reel 21. The grinding wheel is then positioned at a second end of cutting reel 20, opposite the first end, and adjusted until the grinding wheel touches perimeter surface 21. The grinding wheel is then moved back and forth in a reciprocating fashion along perimeter surface 21 of cutting reel 21 in the direction of shaft 24 of cutting reel 20, while cutting reel 20 is being about spun about shaft 24 counter to the direction of spin of the grinding wheel in order to grind or “square off” the edges of the helical blades 22.
While “touch off” grinding squares the edges of each helical blade 22, because the shaft of the grinding wheel is paralleled with perimeter surface 21 of the cutting reel 20, a “touch off” process does not “square” or “true” the overall shape of cutting reel 20 (i.e., it does not remove the conical shape). Since the grinding wheel is parallel to perimeter surface 21 of cutting reel 20, if the perimeter surface 21 of cutting reel 21 had a conical shape before touch-off grinding, the perimeter surface 21 of cutting reel 20 will maintain the conical shape after completion of the touch-off grinding process. If the conical shape of the cutting real is severe enough, performance of the cutting reel can be adversely affected. Also, if the grinding wheel shaft does not align closely enough with the direction of the rotational shaft 24 of cutting reel 20, the entirety of the edges of each of the helical blade 22s may not be sharpened. Users sometimes carry out the “touch off” grinding or sharpening process in order to save time (due to simplicity of the process) and/or when wear on a cutting reel is minimal.
Another type of grinding process, sometimes referred to herein as a “squaring process” or “trueing process” is carried out to return the perimeter surface 21 of cutting reel 20 to a true cylindrical shape. According to such a process, rather than paralleling the shaft grinding wheel to perimeter surface 21 of cutting reel 20, the grinding wheel shaft is paralleled with the rotational shaft 24 of cutting reel 20 in both a vertical direction (x-z plane) and a horizontal direction (x-y plane). The grinding wheel is then moved back and forth in a reciprocating fashion in the direction of shaft 24 of cutting reel 20 as cutting reel 20 is spun counter to the grinding wheel to thereby square-off each helical blade and, thereby square or true to cutting reel to a true cylindrical shape (i.e., removes the coning).
A third type of grinding process, sometimes referred to as a “relief grinding process”, or simply “relief grinding” involves grinding a relief chamfer onto a back of each helical blade. According to one example, such process comprises a two-part process. In a first part, a “trueing” or “squaring” grinding process is carried out to ensure that the cutting reel has a true cylindrical shape. In a second part, a grinding wheel is successively guided along a back edge of each individual helical blade to create a relief or chamfer on the back edge which thereby forms a finer and more efficient cutting edge on each helical blade.
In order to ensure that the grinding process returns reel 20 and blades 22 to OEM specifications, reel 20, and thus, helical blades 22, must be properly positioned and aligned relative to the grinding wheel(s) used during the grinding process. Some grinding systems secure to the front roller of the mower unit, such as front roller 16 of mower unit 10 illustrated above by
In contrast to the distance dF between the centerlines of the front roller 16 and reel 20, while the vertical position of rear roller 14 may vary, the horizontal distance dR between the centerlines of the rear roller 14 and shaft 24 of cutting reel 20 of a given model of mowing unit is typically at a constant distance, or at least within a tight range of distances. Additionally, attachments and accessories, such as brushes, groomer, and thatchers, for example, are not typically mounted on the rear of the mowing units.
As described below, the rear mounting brackets are linearly moveable in the horizontal plane (x-y plane) to preselected positions corresponding to different types of mower units (e.g., different models and manufacturers), and are rotatable together as a unit about a pivot axis so as to provide quick and accurate horizontal alignment of reel 20 (i.e., in a horizontal x-y plane) relative to a grinding wheel axis that is at a fixed horizontal position to thereby enable accurate and reproducible spin grinding and relief grinding processes. Additionally, each end of the grinding axis of the grinding wheel is independently adjustable in the vertical direction (i.e., in the x-z plane) to enable touch-off grinding of reel 20. In other examples, grinding system 50 further includes a controller that provides automated paralleling of rotational axis 24 of reel 20 with the grinding wheel axis in at least the vertical plane based on inputs from one or more alignment gauges. As such, according to examples which will be described in greater detail herein, grinding system 50 enables accurate spin and relief grinding processes while also enabling touch-off grinding.
With reference to
A clamping assembly 70 includes a flange 72 to secure a rear roller 14 to mounting brackets 64 (v-brackets) via a locking mechanism 74 (e.g., a cam mechanism).
A front mounting assembly 80 includes a vertically adjustable support pedestal 82 and a clamping mechanism 84 to secure to a front roller 16 of a mower unit 10.
A spin drive motor 90 is employed to couple to shaft 24 and to drive/spin a reel 20 of a mower unit 10 mounted to grinding system 50. In one example, spin drive motor 90 is mounted to an articulating arm system 92.
A traverse base assembly 100 includes end plates 102a and 102b between which a guide system 104, such as guide rods 104a and 104b, and a grinding shaft 106 (having a grinding axis 108) extend. In one example, grinding shaft 106 is driven by a grinder drive motor 107 via a belt 109 (see
In one example, a spin-grinding assembly 120, including a spin-grinding carriage 122 and a spin-grinding wheel 124, is mounted to traverse base assembly 100, with carriage 122 slideably coupled to guide rods 104a/104b, and spin-grinding wheel 124 coupled to grinding shaft 106. In one example, spin-grinding assembly 120 is driven back and forth along guide rods 104a/104b and grinding shaft 106 by drive motor 130 via drive belt 132.
With reference to
In one example, spin-grinding assembly 120 and relief-grinding assembly 140 are separately coupled to guide system 104 via engagement mechanisms 128 and 148.
In one example, traverse base assembly 100, including guide system 104, grinding shaft 106, spin-grinding system 120, relief-grinding system 140, and drive motors 107 and 130, is vertically adjustable at each end (such as right end 101a and left end 101b) via respective vertical adjustment systems 150 and 160. In one example, vertical adjustment systems 150 and 160 each include respective hand wheels 152 and 162 for vertically adjusting (i.e., in the z-direction) the right and left ends 101a and 101b of traverse base assembly 100 (see arrows 103a/103b in
In one example, after the left end 101b is set to the zero position, spin-grinding carriage 122 is moved to location D2 (which is at a known distance D2 from left end 101b of traverse base assembly 100). With reference to
After the desired height dBR has been achieved, as illustrated by
Spin grinding carriage 122 is then moved to location D1 (which is at a known distance D2 from left end 101b of traverse base assembly 100). When at position D1, similar to that illustrated by
Based on the known distances D2 and D1 from the left end 101b of traverse base assembly 100 at which vertical distance measurements dV2 and dV1 were taken, controller 170 determines a distance dADJ by which to adjust right end 101a of traverse base assembly 100 so that grinding shaft 106 is vertically paralleled with rotational axis 24 of cutting reel 20. In one example, controller 170 adjusts the height of right end 101a of traverse assembly 100 by the distance dADJ by operating drive motor 154 via control line 173. In one example, a user may adjust the height of right end 101a by the distance dADJ via wheel 152 (with controller 170 providing indication of proper adjustment via a set of indicating lights, e.g., raise, lower, stop lights).
In one example, after vertical alignment has been achieved between grinding shaft 106 and rotational shaft 24, horizontal alignment is made between grinding shaft 106 and rotational shaft 24 of reel 20. Similar to that described above with regard to vertical alignment, during horizontal alignment, measurements dH2 and dH1 of the distance to the rotational shaft 24 of reel 20 are again taken at locations D2 and D1, except with the electronic linear distance gauge 180 mounted on pin 174 in instead of on pin 172 (see
After grinding shaft 106 has been both vertically and horizontally aligned with rotational shaft 24 of reel 20, a trueing/squaring grinding process is carried out to square or true reel 20 to a cylinder. In one example a relief grinding process may carried out thereafter using relief grinding assembly 140. It is noted that spin grinding assembly 120 and relief grinding assembly 140 are separately and independently coupled to grinding shaft 106 and guide assembly 104 during the spin and relief grinding processes.
Although illustrated as a mechanical gauge, any suitable type of measuring gauge may be employed for gauge 180, such as a laser gauge, for example. In one example, two laser gauges may be mounted to carriage 122, one at each location 172 and 174.
In another mode, grinding system 50 enables touch-off grinding via manual vertical adjustment of grinding shaft 106 via wheels 152 and 154, wherein such touch-off grinding is improved based on use of rear brackets 64 being moveable to horizontal positions corresponding to the type of mower unit being sharpened and to grinding shaft 106 being fixed in the horizontal plane. Such touch-off grinding is performed by independently moving the opposing ends 101a and 101b in the z-direction to parallel grinding shaft 106 with the perimeter surface 21 of cutting reel 20.
In a trueing/squaring grinding process, grinding system 50 provides accurate trueing or squaring of cutting reels to cylinder shapes based on the use of rear mounting brackets 64 and the paralleling of grinding shaft 106 with rotational shaft 24 of reel 20 via the gauging and alignment system described herein. In another mode, grinding system 50, in addition to providing spin-grinding for trueing the reels to their desired cylindrical shape, further provides relief grinding via relief grinding assembly 140.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
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62627002 | Feb 2018 | US |