GB2346580A

GB2346580A - Cutting device with a safety lock for a pivotable tool housingand a cover

Info

Publication number: GB2346580A
Application number: GB9902894A
Authority: GB
Inventors: Chui-Tsun Chang
Original assignee: Corp P & F Brother Ind
Current assignee: Corp P & F Brother Ind
Priority date: 1999-02-09
Filing date: 1999-02-09
Publication date: 2000-08-16
Anticipated expiration: 2019-02-09
Also published as: DE29903177U1; GB9902894D0; GB2346580B

Abstract

A cutting device includes a tool housing 20 which is mounted pivotally on a support 11 in a raised position and turnable downward to a lower operative position. A saw blade 21 is mounted rotatably on the tool housing 20, and has a cutting portion extending out of a bottom open end 202 of the tool housing 20. A cover member 22 is mounted pivotally on the tool housing 20 to move inward or outward of the tool housing 20 so as to uncover or cover the cutting portion of the cutting tool 21. A safety lock 30 is mounted on the tool housing 20 for locking the cover member 22 relative to the tool housing 20. The safety lock 30 includes a latch pin 34 for projecting into the cover member 22 from the tool housing 20 so as to releaseably engage the cover member 22, and a handle 321 manually operable to control the latch pin 34.

Description

CUTTING DEVICE WITH A SAFETY LOCK FOR A PIVOTABLE TOOL HOUSING AND A COVER This invention relates to a cutting device, more particularly to a cutting device having a safety lock for preventing accidental downward movement of pivotal tool housing and a cover of a saw blade when the cutting device is not in use.

Fig. 1 shows a conventional cutting device. This type of cutting device is handy in use and suitable for machining various materials, and is a popular tool among cutting devices as well. Generally, the cutting device is mounted with a saw blade or emery wheel as cutting tool. Therefore, there resides potential risk if the saw blade or emery wheel is undesirably actuated by accidental touching of the on/off switch of the cutting device. To ensure user safety, the cutting device is generally provided with a safety lock-for preventing the cover from accidentally moving to an uncovering position.

The conventional cutting device 10 as shown in Fig. 1 includes a linkage member 12 pivotally mounted inside a tool housing 11. The linkage member 12 is an L-shaped rod with a stopper 121 projecting outward from a front end thereof. A safety lock mechanism is provided inside the tool housing 11 and includes an interference plate 13 having a recess 131 disposed on one end of the interference plate 13. When the recess 131 interlocks with the stopper 121, the tool housing 11 is restricted from being pressed downward, thereby achieving the desired function for safety. The interference plate 13 is also provided with a slot 132 on the other end. A lever member 14 is pivotally mounted inside the tool housing 11, and has one end slidably received in the slot 132. A pressing action on a pressing button 15 disengages the recess 131 from the stopper 121 and allows the tool housing 11 to be pressed downward to commence a cutting operation.

One main drawback of the conventional cutting device 10 is as follows: The interference plate 13 of the safety lock mechanism is directly connected to the lever 14 and the linkage member 12 and acts on the same so as to control or lock movement of the tool housing 11 and the cover. The arrangement as such requires accuracy in positioning the component parts in order-to ensure a proper locking action of the locking mechanism. Moreover, assembly of the components inside the tool housing 11 is difficult and laborious.

Therefore, it is an object of the present invention to provide a cutting device having a safety lock that is mounted on a pivotable tool housing and a pivotable cover independently of a linkage mechanism which is connected to both the tool housing and the cover for controlling the opening and closing of the cover in response to the pivoting movement of the tool housing.

Accordingly, a cutting device according to the present invention includes: a support; a tool housing mounted pivotally on the support in a raised position from the support, the tool housing being turnable downward to a lower operative position and having a bottom open end; a saw blade mounted rotatably on the tool housing and having a cutting portion extending out of the open end; a cover member mounted pivotally on the tool housing for moving inwardly or outwardly of the open end so as to uncover or cover the cutting portion of the cutting tool, the cover member being movable in response to movement of the tool housing between the raised position and the operative position; and a safety lock mounted on the tool housing for locking the cover member relative to the tool housing, the safety lock including a latch pin for projecting into the cover member from the tool housing so as to releaseably engage the cover member, and a handle manually operable to control the latch pin.

In drawings which illustrate an embodiment of the invention, Fig. 1 is a front elevation view of a conventional cutting device; Fig. 2 is a fragmentary front elevation view of a cutting device embodying the present invention; Fig. 3 is an exploded view of a safety lock of the cutting device of Fig. 2; Fig. 4 is a perspective view of the safety lock of Fig. 3; Fig. 5 is a fragmentary cross-sectional view taken along line V-V of Fig. 2 with the latch pin projecting into the cover member; and Fig. 6 is the same view as Fig. 5 but with the latch pin disengaged from the cover member.

Figs. 2 and 3 illustrate a preferred embodiment of a cutting device of this invention. The cutting device 5 includes an upright support 11, a tool housing 20 connected to the upright support 11, and a saw blade 21 pivotally mounted on the tool housing 20. The tool housing 20 has a tool opening 202 disposed at the bottom portion 201 of the tool housing 20. A cutting portion of the saw blade 21 extends out of the tool opening 202. A curved cover member 22 is pivotally mounted on the inner side of the tool housing 20 so as to be rotatable for moving into and out of the tool housing 20, thereby protecting the user from contacting the saw-blade 21 when the cover member 22 moves out of the tool housing 20 and covers the cutting portion of the saw blade 21.

The tool housing 20 is provided with a circular through-hole 23 at the front side of the tool housing 20. The cover member 22 comprises a disc 221 made of alumina and disposed on a center portion of the cover member 22, and a peripheral cover 222 extending outward from the disc 221. The peripheral cover 222 is secured by screw means on the side edge of the disc 221, and is made from transparent reinforced glass fibers. An elongated through-hole 223 is provided on the cover member 22.

Referring now to Figs. 2 to 5, a safety lock 30 is mounted on the outside of the tool housing 20 and includes a body 31, a first lever 32, a second lever 33, and a latch pin 34. The body 31 has an L-shaped frame 311, and a hollow stud 312 projecting outward from one side of the frame 311 for passing through the circular through-hole 23 of the tool housing 22.

A stopper 313 adjacent to the other side of the frame 311 projects outward frsm the body 31 to abut against t-he first lever 32 so as to confine movement of the first lever 32. The first lever 32 is pivotally mounted on the stopper 313 so as to be rotatable about the stopper 313. The first lever 32 includes a handle 321 provided on one end and extending out of the frame 311, a driving end 322 disposed on the other end, and a bulge 323 extending into a first spring 35. The first spring 35 is supported on the body 31 so as to permit the first lever 32 to fulcrum on the body 31. The second lever 33 includes a driven end 331 abutting against the driving end 322 of the first lever 32, and an elongated aperture 332 provided on the other end opposite to the driven end 331 for pivotally mounting the second lever 33 on one side of the frame 311 and connecting the second lever 33 to one end of the latch pin 34 via screw means 333. The latch pin 34 passes through the inner space of the hollow stud 312 and is movably along the extending direction of the hollow stud 312. The latch pin 34 includes a second spring 341 for urging the latch pin 34.

Referring now to Figs. 3 to 6, the hollow stud 312 extends through the circular through-hole 23 of the tool housing 20. The latch pin 34 has an engaging end 342 provided on one end. The engaging end 342 passes through the hollow stud 312 and is urged into the elongated through-hole 223 by the second spring 341.

The engaging end 342 has a recess 343 disposed on the side wall of the latch pin 34 for conveniently assembling and disassembling the latch pin 34. A circular head plug 344 made of plastic is received partly inside the elongated through-hole 223. The use of plastic material for the head plug 344 can reduce the wear rate of the cover member 22 and smoothen the movement of the cover member 22.

From the description provided hereinabove, it can be noted that the safety lock 30 is simply mounted on the outer side of the tool housing 20 and does not have any direct structural relationship with other components, such as components of a linkage mechanism of the cutting device 5. Like the conventional cutting device, the cutting device 5 has a linkage mechanism (not shown) connected to the tool housing 20 and the cover member 22 to control the closing and opening of the cover member 22 in response to the movement of the tool housing 20. The safety lock 30 can be operated manually to lock or control the cover member 22. As the cover member 22 is connected to the linkage assembly, when the cover member 22 is locked, the linkage assembly can be accordingly locked, and the tool housing 20 can be prevented from moving downward to the operative position. The operation of the safety lock 30 is described hereinbelow.

When the cutting device 5 is in the locking condition, a major portion of the engaging end 342 of the latch pin 34 is urged, by the second spring 341, into the elongated through-hole 223 of the cover member 22 to lock the cover member 22 from movement (see Fig. 5).

To operate the cutting device 5, the user may move the handle 321-of the safety lock 30 in a direction shown by arrow (A) in Fig. 6. The driving end 322 of the first lever 32 therefore presses the driven end 331 of the second lever 33 downward, and moves the second lever 33 upward. The-second lever 33 then draws the engaging end 342 to move out of the elongated through-hole 223. The cover member 22 becomes movable when it is released from the engaging end 342 of the latch pin 34. At this state, the user can move the tool housing 20 downward in a conventional manner.

Claims

Claims: 1. A cutting device comprising: a support; a t-ool housing mounted pivotally on said support in a raised position from said support, said tool housing being turnable downward to a lower operative position and having a bottom open end; a saw blade mounted rotatably on said tool housing and having a cutting portion extending out of said open end; a cover member mounted pivotally on said tool housing for moving inwardly or outwardly of said open end so as to uncover or cover said cutting portion of said cutting tool, sad cover member being movable in response to movement of said tool housing between said raised positiorr and said operative position; and a safety lock mounted on said tool housing for locking said cover member relative to said tool housing, said safety lock including a latch pin for projecting into said cover member from said tool housing so as to releaseably engage said cover member, and a handle manually operable to control said latch pin.
2. The cutting device of Claim 1, wherein said cover member has a through-hole for receiving said latch pin.
3. The cutting device of Claim 1, wherein said safety lock further includes a casing body, and a linkage mechanism mounted on said casing body and connected to said latch pin and said handle.
4. The cutting device of Claim 3, wherein said linkage mechanism comprises a first lever and a second lever which are pivotally mounted on said casing body, said first lever having a driving end, said second lever having a driven end actuatedby said driving end, said latch pin being mounted on said second lever opposite to said driven end, said handle being disposed on said first lever opposite to said driving end.
5. The cutting device of Claim 4, wherein said linkage mechanism further comprises a first spring loaded on said first lever.
6. The cutting device of Claim 5, wherein said linkage mechanism further comprises a second spring loaded on said latch pin to bias said latch pin to project out of said casing body and engage said cover member.
7. A cutting device substantially as hereinbefore described with reference to and as illustrated in Figures 2 to 6 of the accompanying drawings.

7. The cutting device of Claim 6, wherein said casing body includes an L-shaped frame disposed in contact wit-h a, one side of said tool housing, and a hollow part projecting from said L-shaped frame, said tool housing having a through-hole to receive said hollow part, said hollow part receiving said latch pin.

-8. The cutting device of Claim 7, wherein said latch pin has one end connected to said second lever and an engaging end opposite to said one end, said engaging end being biased to project outward from said hollow part and having a protective plug inserted therein, said protective plug being made of a plastic.

9. A cutting device substantially as hereinbefore described with reference to and as illustrated in Figures 2 to 6 of the accompanying drawings.

Amendments to the claims have been filed as follows 1. A cutting device comprising : a support; a tool housing mounted pivotally on said support in a raised position from said support, said tool housing being turnable downward to a lower operative position and having a bottom open end; a saw blade mounted rotatably on said tool housing and having a cutting portion extending out of said open end; a cover member mounted pivotally on said tool housing for moving inwardly or outwardly of said open end so as to uncover or cover said cutting portion of said cutting tool, said cover member being movable in response to movement of said tool housing between said raised position and said operative position; and a safety lock mounted on said tool housing for locking said cover member relative to said tool housing, said safety lock including a casing body mounted on said tool housing, and a linkage mechanism having a first lever and a second lever which are pivotally mounted on said casing body, said first lever having a driving end and a handle opposite said driving end, said first lever being fulcrumed between said driving end and said handle, said second lever having a driven end disposed adjacent to said driving end to be controlled thereby, and a latch pin mounted on an end of the second lever opposite to said driven end, said latch pin being urged to project into ' saidcc'ermemberfromsa;"toolheusincrihe-'ebyrele..sab!yengaging said cover member, and said second lever being turnable about a point between said driven end and said latch pin to release said latch pin from said cover member.

2. The cutting device of claim 1, wherein said cover member has a through-hole for receiving said latch pin.

3. The cutting device of claim 1 or claim 2, wherein said linkage mechanism further comprises a first spring mounted on said casing body to bias said first lever to move said driving end away from said driven end of said second lever, said handle being operable to cause said driving end to actuate said driven end so as to release said latch pin from said cover member.

4. The cutting device of claim 3, wherein said linkage mechanism further comprises a second spring loaded on said latch pin to bias said latch pin to project out of said casing body and engage said cover member.

5. The cutting device of claim 4, wherein said casing body includes an L-shaped frame disposed in contact with one side of said tool housing, and a hollow part projecting from said L-shaped frame, said tool housing having a second through-hole to receive said hollow part, said hollow part receiving said latch pin.

The cutting device of claim 5, wherein said latch pin has one end connected to said second lever and an engaging end opposite to said one end, said engaging end being biased to project outward from said hollow part and having a protective plug inserted therein, said protective plug being made of a plastic.