WO2019109281A1

WO2019109281A1 - Chamfering planer with negative depth of cut

Info

Publication number: WO2019109281A1
Application number: PCT/CN2017/114886
Authority: WO
Inventors: Marina VOJNOV; Raphael SCHÜTT; Kwok Ting Mok
Original assignee: Tti(Macao Commercial Offshore) Limited
Priority date: 2017-12-07
Filing date: 2017-12-07
Publication date: 2019-06-13

Abstract

A planer includes a body, a first workpiece contact surface configured on the body and a second workpiece contact surface configured on the body. The second workpiece contact surface contacts an external workpiece earlier than the first workpiece contact surface during operation of the planer. The second workpiece surface is adapted to be offset from the body more than the first workpiece contact surface.

Description

CHAMFERING PLANER WITH NEGATIVE DEPTH OF CUT

FIELD OF INVENTION

This invention relates to handheld power tools, and in particular chamfering planers.

BACKGROUND OF INVENTION

Chamfering planers are a particular type of planers used to create chamfering corners on an otherwise angled portion of a workpiece. For example, the chamfering corners are formed as decorative edges on railings or decks. To be able to create the chamfering corners, the planer preferably contains a V-notch at the shoes for guiding the planer during operation along the angled portion of the workpiece before it is cut. The cutting can be accomplished by have a rotating blade of the planer configured between two shoes of the planer along the forward direction.

However, existing chamfering planers suffer from the problem that the available sizes of the resultant chamfering corners are limited. To adjust the size of the chamfering corner, existing chamfering planers often utilize an manually operable knob to adjust the vertical offset of the front shoe, so that with a larger difference between the front shoe and the rear shoe in terms of their vertical position, the resultant chamfering corner could be larger (deeper) . However, for such conventional chamfering planers it is not possible to make the chamfering corner size to be smaller, as usually the smallest size would that of a V-notch at the shoes. Alternatively, there have been chamfer planers with multiple V-notches configured on the shoes, but such tools often lead to an imbalance during use since the V-notches are not configured along the central line of the shoes.

SUMMARY OF INVENTION

In the light of the foregoing background, it is an object of the present invention to provide an alternate chamfering planer which eliminates or at least alleviates the above technical problems.

The above object is met by the combination of features of the main claim; the sub-claims disclose further advantageous embodiments of the invention.

One skilled in the art will derive from the following description other objects of the invention. Therefore, the foregoing statements of object are not exhaustive and serve merely to illustrate some of the many objects of the present invention.

Accordingly, the present invention, in one aspect, is a planer which includes a body, a first workpiece contact surface configured on the body and a second workpiece contact surface configured on the body. The second workpiece contact surface enters into contact with an external workpiece earlier than the first workpiece contact surface during operation of the planer. The second workpiece contact surface is adapted to be offset from the body more than the first workpiece contact surface does.

Preferably, the first workpiece contact surface is fixedly mounted at the bottom of the body. The second workpiece contact surface is movably connected to the bottom of the body.

More preferably, the second workpiece contact is connected to an adjusting module of the planer which allows a user to manually adjust the offset of the second workpiece contact surface from the body.

According to a variation of the preferred embodiments, the adjusting module contains a user actuated member which is rotatable. The second workpiece contact surface is coupled to the user actuated member so that rotation of the user actuated member drives the second workpiece contact surface to move closer to or away from the body.

In one specific implementation, the user actuated member is a knob formed with interior threads and prohibited from moving relative to the body along a linear direction. The second workpiece contact surface is connected to a screw rod with exterior threads, so that the second workpiece contact surface is connected to and linearly movable to the knob.

According to another variation of the preferred embodiments, the second workpiece contact surface is movable between a first position where the second workpiece contact is offset from the body more than the first workpiece contact surface, and a second position where the second workpiece contact is offset from the body less than the first workpiece contact surface.

According to one implementation, the first workpiece contact and the second workpiece contact are a rear shoe and a front shoe of the planer respectively. The rear shoe and the front shoe are aligned along a longitudinal direction of the planer.

According to another implementation, a V-shape groove is formed on the second workpiece contact surface along its central line.

According to a further implementation, the planer further contains a battery pack that is detachably connected to the body.

There are many advantages to the present invention. Apparently, by making use of the negative Depth of Cut (DoC) , the proposed chamfering planer is able to extend the chamfer size range. Conventional chamfer planers which utilize positive DoC can only produce large chamfer sizes, and in particular those equal to or larger than the V-notch at the bottom of the shoes. In the present invention, the chamfer planer is able to produce chamfer size even smaller than the V-notch. Therefore, the present invention provides a cost-saving solution to the user that multiple chamfer sizes can be achieved without the need to purchase another chamfer planer. It also helps to the user to reduce weight during transportation, and make the operation easier without the need to change from one planer chamfer to another in the interim.

BRIEF DESCRIPTION OF FIGURES

The foregoing and further features of the present invention will be apparent from the following description of preferred embodiments which are provided by way of example only in connection with the accompanying figures, of which:

Fig. 1 is a perspective view of the planer working on a plank according to one embodiment of the present invention.

Fig. 2 shows the cross-sectional view of the interior of tool body of the planer in Fig. 1.

Fig. 3 is a separate view of the adjusting module of the front shoe in the planer in Fig. 2.

Fig. 4 shows the dial for the adjusting module in the planer in Fig. 2.

Fig. 5 and Fig. 6 show respectively the offset of the front shoe and the rear shoe with respect to the body and the blade of the planer in Fig. 1 in the positive DoC and the negative DoC circumstances.

Fig. 7 is an illustration of the scale plate of the knob of the planer in Fig. 1 showing different cutting effects on the workpiece in each mode.

In the drawings, like numerals indicate like parts throughout the several embodiments described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

As used herein and in the claims, “couple” or “connect” refers to electrical coupling or connection either directly or indirectly via one or more electrical means unless otherwise stated.

Terms such as “horizontal” , “vertical” , “upwards” , “downwards” , “above” , “below” and similar terms as used herein are for the purpose of describing the invention in its normal in-use orientation and are not intended to limit the invention to any particular orientation.

Referring now to Fig. 1, the first embodiment of the present invention is a chamfer planer 24 which is battery-operated. The chamfer planer 24 includes body having a housing 30 in which driving parts like the motor and transmission parts (all not shown) are received, as will be described in more details later. A handle 28 protrudes upwardly from the housing 30. A battery pack 26 is removably installed to the rear end of the housing 30 to provide electric power to motors and other components. A user actuated knob 32 is configured at the head portion of the housing 30 for the user to adjust the size of the chamfer formed by the chamfer planer 24. A dial 34 is movably configured on the housing 30 with the knob 32 protruding from the center of the dial 34. The knob 32 and the dial 34 are adapted to rotate together. In addition, on the housing 30 two exhaust ports 50 extend along opposite directions to direct air flows containing dusts (which are generated during operation of the chamfer planer 24) to external dust bags (not shown) . An exhaustion direction switch 52 is connected to internal mechanisms (not shown) between the two exhaust ports 50 to selectively force the air flows to exit through one of the two exhaust ports 50. In the scenario as shown in Fig. 1 the chamfer planer 24 operates on an edge 22 of a workpiece 20 by a front shoe and a rear shoe (both not shown) of the chamfer planer 24.

Turning now to Figs. 2 and 3, which show the internal structure of the chamfer planer described above, including the structure of the adjusting module (including the knob 32) . The handle 28 which forms a substantially arc shape as being viewed from the side has a trigger switch 36 configured thereon for the user to actuate the motor 42. The trigger switch 36 is connected to and adapted to urge a micro switch 54 inside the handle 28. The micro switch 54 then connects to a control part (not shown) of the chamfer planer. On the other side, the motor 42 as located at substantially the central part of the housing 30 is connected to the battery pack (not shown) and the control part. The motor 42 also has its output driving power delivered to a cutting head 38 which is exposed partially from the housing 38 at the bottom surface thereof so that the two blades 48 mounted on the cutting head 38 may cut a workpiece. The cutting head 38 is connected to the motor 42 by a pulley mechanism (not shown) in order to receive the driving power from the motor 42. At the front joint of the handle 28 and the housing 30, there is a valve 56 for controlling the exhaustion direction through one of the exhaustion ports as mentioned previously.

The details of the above parts including the motor 42, the control part, the trigger switch 36, the pulley mechanism, the exhaust switch 52 and exhaust ports 50, the battery pack 28, the cutting head 38 and the blades 48 are all well-known to skilled persons in the art, so they will not be described in any further details herein.

Continue with Figs. 2-3, the chamfer planer contains two shoes configured at the bottom of the housing 30, namely a front shoe 40 and a rear shoe 44. For the sake of description the front shoe 40 and the rear shoe 44 are also called a second shoe and a first shoe herein. The rear shoe 44 is fixedly connected to the housing 30 meaning that there is no relative movement between the two. In comparison, the front shoe 40 is movably connected to the housing 30. Each of the front shoe 40 and the rear shoe 44 as skilled persons would understand has a substantially flat shape like plates. The gap 46 between the front shoe 40 and the rear shoe 44 allows the cutting head 38 to expose partially from the housing 30.

The knob 32 connects to the housing 30 in such a way that the knob 32 is rotatable relative to the housing 30, but the knob 32 is not able to move linearly relative to the housing 30. In other words, the knob always has the vertical position as shown in Fig. 2 that its relative position to the housing 30 or other components such as the handle 28 remains unchanged at any tie. The knob 32 has substantially mushroom shape, and its bottom end 32a is hollow and has interior threads to receive a screw rod 58 which has exterior threads. The screw rod 58 is movable linearly with respect to the knob 32, and thus the housing 30. On the other end of the screw rod 58, the front shoe 40 is fixedly connected so that the screw rod 58 is adapted to move linearly together with the front shoe 40. At the bottom face of the front shoe 40, there is a V groove 60 formed along a central line (not shown) of the front shoe 40.

Fig. 4 shows clearly the dial 34 that is configured on the chamfer planer of Fig. 1. For clarity the knob is not shown in Fig. 4. The dial 34 has a ring shape on the surface of which multiple indexes 64 are marked to help the user choose desired chamfer sizes. The meanings of the indexes 64 will be described in more details later, but as shown in Fig. 4 a pointer 62 printed on the housing 30 points to a “P” position on the dial 34 which means that the front shoe is now at its default position where the front shoe and the rear shoe should be offset from the body at the same amount so that they appear to be flush. If the user rotates the knob by his hand, then the dial 34 will rotate at the same time, and the pointer 62 would indicate the current chamfer size that the user selects by pointing to a respective index 64 on the dial.

Now turning to the operation of the device described above, Figs. 5 and 6 show how the chamfer planer according to the present invention may be switched between a default (parking) position of the front shoe, a positive DoC, and a negative DoC. Here the positive DoC means that the front shoe 40 is less offset from the housing 30 than the rear shoe 44, as illustrated in Fig. 5. The negative DoC means that the front shoe 40 is more offset from the housing 30 than the rear shoe 44, as illustrated in Fig. 6. The amount of offset of the rear shoe 40 to the housing 30 is fixed, but the front shoe 40 as mentioned above can be moved linearly (along a vertical direction in Figs. 5 and 6) as a result of the user manipulating the knob of the adjusting module. Suppose that the front shoe 40 is initially at a default position where the front shoe 40 and the rear shoe 44 are flush, in order to obtain a relatively larger chamfer size the user needs to rotate the knob along a first rotational direction to raise the front shoe 40 in order to obtain a positive DoC as shown in Fig. 5. In the positive DoC setting, the cutting head 38 is able to cut a larger portion of the edge on the workpiece since the vertical heights of the front shoe 40 and the rear shoe 44 are different, with the depth of the V-groove on the bottom face of the front shoe 40 (not shown in Figs. 5-6) further adding to such difference. In comparison, in order to obtain a relatively smaller chamfer size the user needs to rotate the knob along a second rotational direction opposite to the first rotational direction to lower the front shoe 40 in order to obtain a negative DoC as shown in Fig. 6. In the negative DoC setting, the cutting head 38 is able to cut a smaller portion of the edge on the workpiece (which is even less than the dimension of the V-groove) since the vertical heights of the front shoe 40 and the rear shoe 44 are closer than in the positive DoC settings, with the depth of the V-groove further reducing such difference. The front shoe 40 lifts up or lowers down as it is fixedly connected to the screw rod as mentioned above, where the screw rod itself moves up and down due to its thread connection to the knob that is fixedly connected to the housing of the chamfer planer along the vertical direction.

Fig. 7 shows the illustration of cutting effects of the chamfer planer under different user settings, each of the user setting indicated by a corresponding index 64 on the dial 34. In each of the illustrations the relative position of the front shoe 40, the rear shoe 44, the cutting head 38, and also the size of the resulted chamfer 66, are shown. The line 68 in Fig. 7 generally represents a boundary between a negative DoC cutting mode region 70 and a positive DoC cutting mode region 72 on the dial 34.

The exemplary embodiments of the present invention are thus fully described. Although the description referred to particular embodiments, it will be clear to one skilled in the art that the present invention may be practiced with variation of these specific details. Hence this invention should not be construed as limited to the embodiments set forth herein.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only exemplary embodiments have been shown and described and do not limit the scope of the invention in any manner. It can be appreciated that any of the features described herein may be used with any embodiment. The illustrative embodiments are not exclusive of each other or of other embodiments not recited herein. Accordingly, the invention also provides embodiments that comprise combinations of one or more of the illustrative embodiments described above. Modifications and variations of the invention as herein set forth can be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated by the appended claims.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

For example, on the dial of the chamfer planer as shown in the above embodiments there are certain indexes showing predetermined chamfer sizes of the exemplary chamfer planer. Skilled person would have no difficulties in realizing that the chamfer sizes can be varied according to practical needs by changing for example the rotation-offset ratio of the adjusting module. The dial can also be modified to indicate different chamfer sizes according to practical needs.

Claims

A planer, comprising:

a) a body;

b) a first workpiece contact surface configured on the body; and

c) a second workpiece contact surface configured on the body;

wherein the second workpiece contact surface enters into contact with an external workpiece earlier than the first workpiece contact surface during operation of the planer; the second workpiece contact surface adapted to be offset from the body more than the first workpiece contact surface does.
The planer of claim 1, wherein the first workpiece contact surface is fixedly mounted at the bottom of the body; the second workpiece contact surface being movably connected to the bottom of the body.
The planer of claim 2, wherein the second workpiece contact is connected to an adjusting module of the planer which allows a user to manually adjust the offset of the second workpiece contact surface from the body.
The planer of claim 3, wherein the adjusting module comprises a user actuated member which is rotatable; the second workpiece contact surface coupled to the user actuated member so that rotation of the user actuated member drives the second workpiece contact surface to move closer to or away from the body.
The planer of claim 4, wherein the user actuated member is a knob formed with interior threads and prohibited from moving relative to the body along a linear direction; the second workpiece contact surface connected to a screw rod with exterior threads, so that the second workpiece contact surface is connected to and linearly movable to the knob.
The planer of claim 3, wherein the second workpiece contact surface is movable between a first position where the second workpiece contact is offset from the body more than the first workpiece contact surface, and a second position where the second workpiece contact is offset from the body less than the first workpiece contact surface.
The planer according to any one of the preceding claims, wherein the first workpiece contact and the second workpiece contact are a rear shoe and a front shoe of the planer respectively; the rear shoe and the front shoe aligned along a longitudinal direction of the planer.
The planer according to any one of the preceding claims, wherein a V-shape groove is formed on the second workpiece contact surface along its central line.
The planer according to any one of the preceding claims, further comprises a battery pack that is detachably connected to the body.