Patent Application
20110237166
1. Field of the Invention
The present invention relates generally to a grinding technique for saw blade, and more particularly to a bed-type circular saw blade grinder.
2. Description of the Related Art
A circular saw is widely used in various fields such as machining and carpentry for sawing and processing a work piece. After a period of use, the circular saw blade will be inevitably worn out to affect the processing quality. Under such circumstance, it is necessary to grind the saw teeth of the circular saw blade and recover the sharpness of the saw teeth. Taiwanese Patent Application No. 076201481 discloses a grinder specifically for a circular saw blade. The grinder is characterized in that an electromagnetic retainer is used to retain a circular saw blade to be ground. A mechanical claw is used to control the pitch between the ground saw teeth. An advanced grinding motor transmission mechanism is used to drive a universally adjustable grinding head for multi-angle grinding each saw tooth three times. After ground, the circular saw blade is restored to its original sharp state for single-point cutting a work piece.
The above circular saw blade grinder has a complicated structure and is uneasy to use.
It is therefore a primary object of the present invention to provide a bed-type circular saw blade grinder, which has a simplified structure and is easy to manufacture at lower cost. Moreover, the bed-type circular saw blade grinder can be more conveniently used with the possibility of failure minimized.
To achieve the above and other objects, the bed-type circular saw blade grinder of the present invention includes: a bed section; a support section having a predetermined height, a first end of the support section being fixedly connected with the bed section, a second end of the support section being coaxially connected with a circular saw blade having a central shaft hole, whereby the circular saw blade is rotatable about an axis of the shaft hole; a rotary seat pivotally disposed on the bed section via a pivot shaft, which is spaced from the support section, the pivot shaft having an axis parallel to an axis of the support section, whereby the rotary seat is reciprocally rotatable about the pivot shaft between a first position and a second position, the rotary seat having a first connection section and a second connection section, which are respectively positioned on two sides of the pivot shaft; a circular saw blade restriction section disposed at the first connection section for driving the circular saw blade to intermittently rotate; and a grinding unit disposed at the second connection section. The grinding unit has a grinding piece for grinding saw teeth of the circular saw blade. When the rotary seat is pivotally rotated between the first and second positions, the rotary seat respectively via the first and second connection sections drives the circular saw blade restriction section and the grinding unit to move with the rotary seat. When the rotary seat is positioned in the first position, the grinding piece of the grinding unit is leant against a saw tooth of the circular saw blade to grind the saw tooth. When the rotary seat is positioned in the second position, the grinding piece of the grinding unit is spaced from the saw tooth of the circular saw blade. When the rotary seat is moved from the second position to the first position, the circular saw blade restriction section drives the circular saw blade to rotate.
The present invention can be best understood through the following description and accompanying drawings, wherein:
Please refer to
The bed section 20 is a board body with a certain weight as a base on which the other components of the bed-type circular saw blade grinder 10 are mounted. The bed section 20 also helps in stabilizing the operation of the bed-type circular saw blade grinder 10.
The support section 30 has a substantially U-shaped support body 31 with a certain height. Two wing plates 311 laterally extend from bottom ends of two sides of the support body 31. The wing plates 311 are attached to and fixedly connected with an upper face of the bed section 20. A top wall of the support body is formed with a shaft hole 32. The shaft hole 32 has an axis normal to the upper face of the bed section 20. A shaft rod 33 with a certain length is coaxially slidably fitted in the shaft hole 32. A middle section of the shaft rod 33 is formed with an annular shoulder section 331, which is directed downward. The annular shoulder section 331 abuts against an upper face of the top wall of the support body 31. A resilient member 34, which is a compression spring, is fitted around the shaft rod 33. Two ends of the resilient member 34 respectively abut against a lower face of the top wall of the support body 31 and a washer 332 of bottom end of the shaft rod 33 for providing resilient force to increase frictional force between the annular shoulder section 331 and the upper face of the top wall of the support body 31.
The rotary seat 40 has a case-like seat body 41 with a certain configuration. The seat body 41 is pivotally connected with the bed section 20 via a pivot shaft 411. The pivot shaft 411 has an axis parallel to the axis of the shaft rod 33. The pivot shaft 411 is spaced from the support section 30. The seat body 41 is formed with a perforation 42. A top end of the shaft rod 33 is coaxially positioned in the perforation 42. A slot-like first connection section 43 and a slot-like second connection section 44 are formed through the seat body 41 and positioned on two sides of the pivot shaft 411. A substantially vertical rocking rod 45 is fixedly disposed on the seat body 41. A user can apply a force to the rocking rod 45 to drive and rotate the rotary seat 40 about the pivot shaft 411 between a first position and a second position. The perforation 42 is arcuate and has a diameter larger than that of the shaft rod 33 slidably positioned in the perforation 42. The arc length of the arcuate perforation 42 corresponds to a distance between the first and second positions. Accordingly, the shaft rod 33 is positioned in the perforation 42 to restrict the rotary seat 40 to pivotally move within a range between the first and second positions.
The circular saw blade restriction section 50 is slidably disposed at the first connection section 43. The circular saw blade restriction section 50 includes a stepped first slide plate 51, which is slidably connected to the first connection section 43 via a conventional quick-release member 52. The circular saw blade restriction section 50 further includes a rock arm 53. A first end of the rock arm 53 is pivotally connected to the slide plate 51 via a pivot shaft. A pawl pin 54 is perpendicularly disposed at a second end of the rock arm 53. A torque spring 55 is fitted around the pivot shaft of the rock arm 53. Two ends of the torque spring 55 are respectively connected with the slide plate 51 and the rock arm 53, whereby the torque spring 55 can provide a resilient force to pull and swing the rock arm 53 toward the pivot shaft 411 of the rotary seat 40.
The grinding unit retainer seat 60 includes a flat second slide plate 61 formed with a square through hole 62. An elongated bar-like locating plate 63 is attached to the second slide plate 61. The locating plate 63 has a length larger than the maximum diameter of the square hole. A securing bolt 64 passes through the locating plate 63 to connect the locating plate 63 to the second connection section 44 so as to locate the second slide plate 61. An upright plate 65 is perpendicularly disposed on the second slide plate 61. A connection plate 66 is attached to the upright plate 65 and a retainer ring 67 is connected with the connection plate 66.
The connection plate 66 is not only used to connect the retainer ring 67 with the upright plate 65, but also used to adjust the position relationship between the retainer ring 67 and the upright plate 65. To speak more specifically, the connection plate 66 is formed with a connection hole 661 and an arcuate adjustment slot 662. Two fixing pins are passed through the connection hole 661 and the arcuate adjustment slot 662 to connect the connection plate 66 with the upright plate 65. Accordingly, the connection plate 66 can be rotated about an axis of the connection hole 661 to change the position relationship between the retainer ring 67 and the upright plate 65. After the adjustment is completed, the fixing pin in the arcuate adjustment slot 662 is tightened to locate the retainer ring 67 in the adjusted position.
The grinding unit 70 pertains to prior art and thus will not be described in detail hereinafter.
According to the above arrangement, in use of the bed-type circular saw blade grinder 10, the circular saw blade 80 is coaxially fitted on top end of the shaft rod 33, whereby the circular saw blade 80 can be rotated about the shaft rod 33. The pawl pin 54 of the circular saw blade restriction section 50 is engaged in a tooth space of the circular saw blade 80, whereby the circular saw blade 80 can be only one-way intermittently rotated. Such technique pertains to prior art and thus will not be described in detail hereinafter. However, it should be noted that when the rotary seat 40 is moved from the first position to the second position, the pawl pin 54 is slid along the tooth back to a second next tooth space. When the rotary seat 40 is restored from the second position to the first position, the pawl pin 54 draws the circular saw blade 80 and makes it rotate by two tooth spaces. Alternatively, as desired, the pawl pin 54 can draw the circular saw blade 80 and make it rotate by only one tooth space when the rotary seat 40 is restored from the second position to the first position.
Moreover, when the rotary seat 40 is positioned in the first position, one face of a grinding piece 71 of the grinding unit 70 is leant against the tip of a saw tooth of the circular saw blade 80 to grind the saw tooth. When the rotary seat 40 is moved from the first position to the first position, the grinding piece 71 leaves the saw tooth in a non-sliding manner. After the rotary seat 40 is restored to the first position, the grinding piece 71 approaches to and lean against a first next or a second next saw tooth in a non-sliding manner to grind the first next or second next saw tooth.
In conclusion, the present invention has the following advantages:
The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.
