Patent Application
20150000493
The following is a tabulation of some prior art that presently appears relevant:
A table saw is a power tool commonly used to facilitate forming a work-piece to a desired shape. To shape or cut the work-piece, a circular saw blade exposed above the table surface is rotated at a fixed point while the work-piece is slid on the table surface towards the blade. All table saws present a safety concern because saw blades are inherently sharp by design and rotate at a high rate of speed. Accordingly, injury such as severed digits and deep lacerations can occur almost instantaneously. In response to the dangers inherent with an exposed blade moving at high speed, a number of safety systems have been developed. One such safety system is a blade guard. Blade guards movably enclose the saw blade, thereby providing a physical barrier that must be moved before the rotating blade is exposed. While blade guards are effective in preventing injuries they can be removed for better convenience of use or removed because the blade guard is not compatible for use with a particular shaping device. For example, a blade guard is typically not compatible with a dado blade and must typically be removed when performing non-through cuts.
Table saw safety systems have also been developed which are intended to stop the blade when a user's hand or fingers touches the blade. This type of safety feature is commonly employed thru braking devices that are physically inserted into the teeth of the blade. Upon actuation of this type of braking device, however, the blade and breaking member are typically ruined and for each time the safety device is actuated, significant resources must be expended to replace the blade and the braking member. Moreover, if spare blade and braking member are not on hand, a user must travel to a store to obtain replacements. Another shortcoming of this type of safety device is that, without having to damage the blade and braking member, the user has no means of testing whether the electronic controls responsible for stopping the blade are properly functioning. Defects in manufacturing and quality control failures are always a possibility and in the event the electronic controls are defective, the user will have no way of knowing whether the safety feature is functioning. This could lead to a fake sense of security that might perpetuate increased risk taking on part of the user and thus, increase the risk of injury. A further disadvantage of such a system is that the shaping device must be toothed and the safety system is prone to actuate when the material being cut is damp or wet. As such, wet or damp materials must be dried first before cutting, otherwise the user risks the chance of the safety system actuating and causing the needles expense of replacing the blade and the braking member. Thus, while effective, this type of safety system can be expensive, inconvenient and uncertain.
Other devices commonly called jigs have also been developed in a variety of configurations to again reduce the possibility of having a hand or finger contact the blade. The various jig configurations generally enhance the operator's safety by increasing the distance of the user's hand away from the blade while making a cut. Although the risk to the user is reduced, the user must still assume a considerable amount of risk, such as the slip of the hand while holding and sliding the jig in relative close proximity to the blade. Another shortcoming of such systems is that they are typically designed for a specific cut. For example, a tenoning jig is only useful for making tenons. Since table saws are commonly used to cut various materials in a variety of ways, the user will have to expend resources for each kind of cut that can be more safely accomplished by use of a jig.
Table saws are also currently configured with manual blade height and angle mechanisms, where the operator must turn a handle to adjust the blade height or angle, also called bevel. Although the height and angle of the blade can be set by slowly turning the handle and carefully aligning needle and tick mark height and angle indicators, setting the height and angle of the blade by this method is prone to inaccuracies because needle and tick mark indicators are susceptible to being thrown out of calibration and because accuracy depends on the user's ability to align the needle and tick mark using the naked eye. To achieve blade height and angle precision, manual measurement of the blade height and angle with a machinist's rule and protractor is typically required. This process often necessitates touching and manually rotating the sharp blade to make an accurate measurement. Although the blade is not rotating at a high rate of speed, the sharp blade can still be a safety concern for the user who will have to physically contact the blade to make the necessary blade height or angle measurements. Moreover, while manually adjusting the blade height and angle in this manner is effective, it is inconvenient because the user must crouch at an awkward position to align his or her eyes to the measuring device and blade while turning the blade height or angle adjustment handle.
Other saw designs such as radial arm saws and slide miter saws have also been developed to provide stationary cutting from above the working platform. However, the rip cut (longitudinal cuts) widths are limited by the blades range of motion and they do not provide moving work-piece cutting capabilities. Furthermore, because the blade is mounted above the working platform, the height of the material that can be cut is limited by the space between the working platform and the blade's supporting mechanism.
In view of the foregoing, it would be advantageous to enhance user safety and convenience by providing the user with a means of making a cut without having the user physically hold and slide the work-piece and without the height limitations inherent in radial arm saw and slide miter saw designs. It would be advantageous to simply clamp the work-piece onto the table surface and have the blade traverse towards the work-piece to make the cut by the simple press of a user interface button or screen. In addition to the stationary work-piece cutting capability just described above, it would be advantageous to be able to also provide the user with a moving work-piece cutting capability. This can be especially useful when conducting rip cuts. For example, a user conducting rip cuts can set the blade in a stationary mode and slide the work-piece towards the blade, but before the user's hand approaches the blade at an unsafe distance, the user can clamp the work-piece, move his/her hands away, adjust the table saw setting via a user interface panel and traverse the blade to complete the cut. It would also be advantageous to adjust the height and angle of the table saw blade by simply entering the desired height and or angle into the user interface panel to automatically and precisely adjust the blade to the desired height or angle via an electronic controls.
In order to overcome the deficiencies noted above, the present table saw with an automated traversing mechanism has been devised. The object of the embodiment is to improve upon known prior art by enhancing user safety, convenience, and work-piece cutting capability by providing the user with an automated means of traversing the blade via electronic controls for conducting stationary work-piece operations as well as moving work-piece operations without the work-piece height limitations of radial and slide miter saw designs. It is also the object of the embodiment to provide the user a convenient means of accurately adjusting the height, angle, and traversing speed of the blade through electronic controls via a user interface panel. As will be more fully described herein, the present saw comprises a horizontally disposed working platform with an elongated blade slot coupled to a main frame and a support frame, a traversing mechanism comprising a carriage coupled to linear guide rails and movable along a traversing path parallel to the blade slot. The carriage mounted beneath the working platform is coupled to a saw blade that protrudes through the slot to cut work-pieces on the platform. Linear actuators operatively coupled to the carriage advance and retreat the carriage along the guide rails at a plurality of positions. Pivotally mounted to the carriage is a tilt plate that supports a blade drive assembly where the blade is mounted and provides a means to rotate the blade wheel and adjust the height of the blade wheel relative to the table surface. The table saw further includes a tilting mechanism used to rotate the tilt plate and the mounted blade drive assembly at an angle desired by the user. Whereby the tilting mechanism supported by the carriage contains a linear actuator in a translating engagement with the tilt plate rotate the tilt plate about its pivot axis relative to the carriage.
The foregoing aspects and many of the attendant advantages of this invention will become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
To site some of the advantages of the table saw 100 compared to a typical table saw that has a blade wheel rotating in a substantially stationary axis in the horizontal direction, as an example, when cutting generally small work-pieces where there is limited work-piece body to firmly hold and slide the work-piece safely by hand towards the rotating blade wheel 113, the user of the table saw 100 can secure the work-piece on the work-piece support platform 110 by any suitable means or using accessories that are typically available for table saws such as hold down clamps 119, which can be anchored and positioned along track 117. Once the work-piece is positioned and secured as desired by the user, the user can traverse the blade wheel 113 using the control panel 115 to make the desired cut. In this manner, a user can perform cuts on generally small work-pieces without bringing their hands in close proximity to the rotating blade wheel 113. Thus, the risk of injury is greatly reduced. Another example is when the user is nearing the end of a cut where the user is running out of sufficient work-piece body to firmly hold and continue feeding the work-piece safely, once the work-piece is within the traversing path of the blade wheel 113, the user can once again secure the work-piece as described above and finish the cut by traversing the blade wheel 113 with the control panel 115.
The components of the table saw 100 that drives the blade wheel 113 to rotate and provide the means to translate the blade wheel 113 in the horizontal, vertical, and angular directions are disposed under the work-piece support platform 110. To that end, please refer now to
Referring now to
The main frame lateral members 111c and 111d form the bases of the linear guide rails 210 and 211 for the traversing mechanism 200. The linear guide rails 210 and 211 are rigidly attached to the main frame lateral members 111c and 111d, respectively, and are configured generally parallel to the lateral direction 150.
The traversing mechanism 200 further includes a carriage assembly 212 slidably coupled to the linear guide rails 210 and 211 via a plurality of linear bearings 214, a traversing motor 215 mounted to a traversing motor mounting frame 217 that is fixedly attached to the main frame longitudinal member 111a, a traversing threaded rod 218 coupled to a traversing motor output shaft 216 on one of its ends and coupled to a traversing hand wheel 219 on its other end, shaft mount bearings 220 and 221 for supporting the traversing threaded rod 218, a vertical support plate 222 attached to a carriage extended member 213, and a traversing nut 223 fastened to the vertical support plate 222 and threadably engaged with the traversing threaded rod 218.
The carriage assembly 212 is composed of a longitudinal member 212c and extended member 213 that extend in the longitudinal direction 151 and lateral members 212a and 212b that extend in the lateral direction 150. The main frame assembly 111 and the carriage assembly 212 are configured and sized to allow the tilt frame 400 (see
Also, as shown best in
In operation, the traversing motor 215 rotates the traversing threaded rod 218, which in turn, moves the traversing nut 223. The traversing motor 215 is selectively reversible so that the traversing threaded rod 218 can be rotated in either direction, thereby allowing the traversing nut 223 to transmit an actuating force on the vertical support plate 222, that is attached to the carriage extended member 213, to advance and retreat the carriage assembly 212 to a plurality of positions along the linear guide rails 210 and 211. Alternatively, the traversing hand wheel 219 can be used to rotate the traversing threaded rod 218 to move the carriage assembly 212, as the user desires. The traversing threaded rod 218 and traversing nut 223 acts like a jack screw, thereby, when the traversing motor 215 is in stop, it holds the carriage assembly 212 firmly in position.
The linear actuator for traversing the carriage assembly 212 is shown as a threaded rod linear actuator and a nut. While the linear actuator is shown as threaded rod linear actuator, it may be any type of closed length linear actuator that can be attached to frame assembly 111 at both ends and can allow the carriage assembly 212 to translate linearly, including, for example, nut and screw, acme threaded rod, linear ball screw, linear track, rack and pinion, or linear slide. The traversing mechanism 200 may include two linear actuators of the same type, or each actuator may be of a different type.
Referring now to
The blade height adjusting device 350 is used to translate the blade wheel 113 from a stowed position to a plurality of raised positions relative to the work-piece support platform 110 (see
Accordingly, the reader will see that the carriage assembly 212 is the framework that supports the tilt frame 400, which the blade driving mechanism 300 and the height adjusting device 350 are mounted to. The tilt plate 400 is pivotably mounted to the carriage via pivot blocks 224 and 225 and pivot about an axis generally parallel to the guide rails 210 and 211.
In accordance with the aspects of the present disclosure, the blade arm 313 and counter arm 315 are configured to ensure a sufficient wrap-around frictional engagement of the drive belt 317 to the pulleys when adjusting the height of the blade wheel 113 between a raised position and a stowed position. To that end, please refer to
The counter arm 315 includes a counter pulley shaft 325 rotationally coupled thereto and a counter pulley 316 is fastened to the counter arm shaft 325. The counter arm 315 has a hole 326 sized to axially fit the axle 318 and cooperatively pivot with the blade arm 313.
The blade arm 313 has a lip 327 that extends from a vertical face of the blade arm 313. The lip 327 is oriented in a generally diagonal direction. Similar to the blade arm 313, the counter arm 315 also has a lip 328 and oriented in the same manner. The lip 327 and lip 328 face each other and are sized and spaced to receive springs 329 to bias the blade arm 313 and counter arm 315, in an opposing manner, causing the blade arm 313 to apply a compressive force against the counter arm 315. Each spring 329 is fastened to lip 327 on one end and fastened to lip 328 on its other end, preferably by fasteners. As shown best in
In operation, as depicted in
With the blade driving motor 310 remaining substantially stationary relative to the tilt frame 400, the blade arm 313 and counter arm 315 are configured to turn in unison such that, as shown in
As shown in
Referring now to
A tilting nut coupling plate 510 is pivotally joined to the tilt plate 400 via pivot frames 513 and 514. The pivot frame 513 and 514 have pivot holes 511 and 515, respectively, and are sized to fit pins 512 that are fixedly attached to the coupling base plate 510. The coupling base plate 510 is retained by the pivot frame 513 to the tilt frame 400 by fasteners.
Still referring to the embodiment of
Referring now to
In operation, the tilting motor 516 rotates the tilting threaded rod 522, which in turn, translates the tilting nut 523 along the axis of the tilting threaded rod 522. The tilting motor 516 is selectively reversible so that the tilting threaded rod 522 can be rotated in either direction. The tilting nut 523 is coupled to the tilting nut coupling plate 510, which is pivotally mounted to the tilt frame 400. When the tilting threaded rod 522 rotates, the tilting nut 523 applies a push or a pull on the tilt frame 400 to rotate about its pivot axis, depending on the direction of rotation of the tilting motor 516.
The universal joint 521 and the tilting nut coupling plate 510 are configured to allow the tilting threaded rod 522 axis to gradually incline as the tilt frame 400 rotates away from it nominal operating position and to gradually recline as the tilt frame 400 rotates towards its nominal operating position. The tilting threaded rod 522 and tilting nut 523 acts like a jack screw; so when the tiling motor 516 is in stop, it holds the tilt frame 400 firmly in position.
With respect to the above description, before explaining at least one preferred embodiment of the herein disclosed invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangement of the components in the following description or illustrated in the drawings. The invention herein described is capable of other embodiments and of being practiced and carried out in various ways which will be obvious to those skilled in the art. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for designing of other structures, methods and systems for carrying out the several purposes of the present disclosed device. It is important, therefore, that the claims be regarded as including such equivalent construction and methodology insofar as they do not depart from the spirit and scope of the present invention.
While all of the fundamental characteristics and features of the invention have been shown and described herein, with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure and it will be apparent that in some instances, some features of the invention may be employed without a corresponding use of other features without departing from the scope of the invention as set forth. It should also be understood that various substitutions, modifications, and variations may be made by those skilled in the art without departing from the spirit or scope of the invention.
