WO2004011179A1

WO2004011179A1 - Hole saw arbor

Info

Publication number: WO2004011179A1
Application number: PCT/SE2003/001242
Authority: WO
Inventors: Jan Rydén
Original assignee: Gsm Industrier Ab
Priority date: 2002-07-26
Filing date: 2003-07-25
Publication date: 2004-02-05
Also published as: SE0202326L; AU2003247320A1; SE0202326D0

Abstract

An adaptor (1) for mounting a rotating tool (5) in a drilling machine, whereby the adaptor comprises an arbor body (2) having a first end with a shank (3) for mounting to a drill chuck, and a second end with a thread (4) for mounting the tool, as well as a thrust member (7) which is arranged on the arbor body (2). The thrust member (7) is movable in an axial direction but not in a rotational direction relatively to the arbor body (2). At least one driving pin (12) is rotatably fixed to the thrust member (7) and directed towards the second end of the arbor body (2) for engaging the tool (5). At least one adjustable locking member (13) is arranged in the thrust member (7) and movable in a direction substantially perpendicular to the longitudinal axis of the arbor body (2). Furthermore at least one biased surface (17) is arranged on the arbor body (2) adjacent to the adjustable locking member (13). The at least one adjustable locking member (13) engages the at least one biased surface (17) when the locking member (13) is moved in a direction towards the arbor body (2), preferably towards the center of the arbor body, and pushes the thrust member (7) towards the second end of the arbor body (2).

Description

HOLE SAW ARBOR

Field of the Invention

The present invention relates generally to an adaptor for rotating tools for mounting in a drilling machine and is more particularly concerned with a new and improved quick release drive arbor for rotating tools such as hole saws and the like.

Prior Art

US patent No. 4,148,593 discloses an arbor assembly 100 including a quick disconnect arbor 101 comprising a thrust member 102 having a selected working position (as shown in Fig. 1) and a release position. The two positions are established by a ball 103 in the thrust member 102 being pushed against the arbor body, towards a hollow 106 in the working position and towards a hollow 107 in the release position, by means of a spring loaded ball 104. The spring loaded ball 104 cooperates with a set screw 105.

Thus, it is prevented that the thrust member slides axially beyond its working and release positions and furthermore that the tool, a saw cup, when desired quickly and easily is released from the arbor in order to either exchange the tool with a new, similar one, or another tool in a different size.

However, during certain operating conditions, such as high drilling speed, the saw cup will vibrate and wobble because it is not sufficiently locked to the thread. This results in inaccurate holes and shortened life-time of the_. tool and the drilling machine.

Summary of the Invention

The main objects of the present invention are to provide a new and improved quick release arbor having means for reducing hole saw wobbling and furthermore to provide such an assembly having a minimum of parts, and not needing cumbersome tools for handling the arbor, e.g. a large wrench .

These objects are achieved by an adaptor for mounting a rotating tool in a drilling machine, said adaptor having at least one locking member, according to independent claim 1. The adaptor comprises an arbor body having a first end with a shank for mounting to a drill chuck and a second end with a thread for mounting the tool, as well as a thrust member, which is arranged on the arbor body. The thrust member is movable in an axial direction but not in a rotational direction relatively to the arbor body. At least one driving pin is fixed to the thrust member, preferably rotatably, and directed towards the second end of the arbor body for engaging the tool. The at least one adjustable locking member is arranged in the thrust member and movable in a direction substantially perpendicular to the axis of the arbor body. Furthermore at least one biased surface is arranged on the arbor body adjacent to the adjustable locking member. The at least one adjustable locking member engages the at least one biased surface when the locking member is moved in a direction towards the arbor body, preferably towards the center of the arbor body, and pushes the thrust member towards the second end of the arbor body. In a preferred embodiment a spring loaded ball in a thrust member and mating grooves in an arbor define a quick release arbor. The arbor is combined and cooperates with a locking member in a thrust member arranged around the arbor. The arbor transmits torque from a drilling machine to a tool lixed to said arbor. The locking member is preferably a screw. When activated, the locking member pushes the thrust member abutting the tool towards the tool, thus both locking the thrust member and reducing vibrations and wobbling due to the tool being more precisely fixed to the arbor by eliminating slack in a thread of said tool towards a threaded end of said arbor on which the tool is screwed.

Other objects will in part be obvious and in part be pointed out in more detail hereinafter. Also other aspects 5 of the invention will be apparent from and elucidated with reference to the embodiments described hereafter.

Brief Description of the Drawings

The present invention will now be described in 10 further detail, reference being made to the accompanying drawings, in which:

FIG 1 is a schematic view of an adaptor according to the prior art ;

FIG 2 illustrates a preferred embodiment according to 15 the invention;

FIG 3A and 3B show the preferred embodiment of Fig. 2 in its release and working positions respectively;

FIGs 4A to 4C shows the arbor body of some preferred embodiments ; 20 FIG 5 illustrates an alternative embodiment of the invention;

FIG 6 is another preferred embodiment of the invention;

FIGs 7A to 7D are embodiments of the thrust member 25 according to the invention; and

FIGs 8A to 8C show alternative arrangements of the locking member according to the invention.

Detailed Description of the Invention

^"3^"0 Figure 2 illustrates an adaptor assembly 1 for mounting a rotating tool in a drilling machine according to a preferred embodiment of the present invention.

The adaptor assembly comprises an arbor body 2 which has a first end with a shank 3 being used for mounting the

35 adaptor assembly 1 in e.g. a drill chuck. The shank 3 is preferably hexagonal in cross section in order to engage the drill chuck without spinning when transferring torque from the drilling machine to the rotating tool. The shape of the shank 3 is however of lower importance and may as 5 well be circular, triangular, rectangular, pentagonal, etc. as long as the drill chuck is able to clamp the shank 3.

In addition to the shank 3, the arbor body 2 comprises at the opposite end a threaded portion 4 for mounting the tool. In a preferred embodiment, the tool is a

10 hole saw 5, but other types of rotating tools such as a grinding wheel or a cutting wheel is equally possible within the scope of the invention. The hole saw 5 is provided with a threaded hole 6 which matches the threaded portion 4 on the arbor body 2.

15 The adaptor assembly 1 according to the invention further comprises a thrust member 7, which is arranged on the arbor body 2. The thrust member 7 is movable in a longitudinal axial direction on the arbor body 2 in order to abut against the hole saw 6 when the thrust member 7 is

20 pushed in a direction towards the hole saw 5. The thrust member 7 is in a preferred embodiment designed as a single unit with a central partially hexagonal aperture 8 for receiving the arbor body 2. In the same way as described in US 4,148,593, the hexagonal aperture 8 engages a

25 corresponding hexagonal part of the arbor body 2 in order to transfer torque to the thrust member 7. The aperture 8 is preferably circular in shape at the top end, i.e. the end closest to the threaded portion 4, in order to provide a block as to restrain the thrust member 7 from sliding too

-3'0 far" towards-the slϊaήk 3 when changing the tool on the adaptor 1.

Moreover, the thrust member 7 is preferably mounted on the arbor body 2 in a spring loaded manner, wherein the thrust member 7 is locked in either a rear position or a

35 forward position. This is e.g. achieved by providing the adaptor assembly 1 with a detent device as described in US 4,148,593. A chamber 15 in the thrust member 7 being in communication with the central aperture 8 of the thrust member 7 accommodates a spring loaded ball 10 which is continuously urged towards the arbor body 2. The arbor body 2 is provided with grooves 11 to define the rear and forward positions of the thrust member 7, whereby the forward position is even called the working position and the rear position is even called the release position. Grooves 11 are either located in the hexagonal portion of arbor 2 or in the non-hexagonal portion towards the chuck- end of arbor 2, as shown in e.g. Fig. 4A. In operation, the spring loaded ball 10 is received in the grooves 11 and locks the thrust member 7. A sufficient force acting in an axial direction on the thrust member 7, e.g. manually exerted by the operator of the arbor assembly when changing the tool, will push the spring loaded ball 10 into the chamber and release the thrust member which is then pushed into the other position. Since the central aperture 8 of the thrust member 7 is at least partially non-circular, the thrust member 7 will not be movable in a rotational direction relative to the arbor body 2. In operation, the arbor body 2 will hence transfer torque to the thrust member 7. The adaptor assembly 1 comprises at least one driving pin 12 being rotatably fixed to the thrust member 7 and directed towards the second, threaded end portion 4 of the arbor body 2 for engaging the hole saw 5. In a preferred embodiment of the invention, two driving pins are used in order to distribute the load from the rotation of the adaptor tool 1 when transferring torque from the drilling machine to the hole saw 5. However, it is understood that more than two driving pins 12 may of course be used. A noteworthy and novel feature of the present invention is an adjustable locking member 13 which is arranged in a threaded hole 14 in the thrust member 7. The adjustable locking member 13 is preferably in form of a small socket head cap screw that mates with the threaded hole 14 in the thrust member 7. The adjustable locking member 13 may also be in form of an ordinary screw or a threaded pin. The threaded hole in the thrust member 2 is aligned in a direction substantially perpendicular to the axis of the arbor body 2. The threaded hole may, however, as shown in the embodiment shown in Figs. 5 and 8C, be somewhat tilted so that the adjustable locking member 13 engages the arbor body 2 in an angle being less than 90 degrees with respect to the axis of the arbor body 2 in a direction towards the threaded portion 4.

By turning the adjustable locking member 13, e.g. by means of an offset screwdriver for a hexagon socket or torx head screw, the threading in the hole and on the screw will cause adjustable locking member 13 to move in a direction towards or away from the arbor body 2 depending on the direction of rotation. The locking member 13 has thus a rest position and a locking position, whereby the locking member 13 is in its rest position when it is not engaged in the arbor body 2.

The arbor assembly according to the invention is operable both with the locking member 13 being engaged in the arbor body, i.e. the locked working position of the locking member, or in the rest position of the locking member, i.e. the locking member not being engaged in arbor body 2. Therefore the arbor may be operable quickly when a tool is installed, with the arbor assembly working in operating mode with the locking member 13 in its rest position, however with less accuracy than in the locked working position. The locked working position of thrust member 7 is in addition to its release and working position defining the way operation of the adaptor according to the invention. In this way, the adaptor according to the invention can quickly be used without locking, but it has the advantageous possibility of a locking position.

Fig . 4B shows a preferred embodiment with the biased surface being defined by a conical hollow 19. The arrangement is thus preferably self centering when tightening the locking member 13 towards the locking position due to an appropriate mating conical front side of matching locking member 13 13. In another embodiment, locking member 13 is not directed towards the center of arbor body 2, but instead e.g. to a beveled groove 18 in arbor body 2 as shown in Fig. 4C , hereby the beveled groove is arranged in a direction substantially rotational around the longitudinal axis of arbor body 2.

According to the invention, at least one biased surface is arranged on the arbor body adjacent to the adjustable locking member. In the preferred embodiment shown in Fig. 2, said biased surface 17 engaged by the locking member is part of a conical hollow 19 which center axis is slightly displaced with respect to the working position towards said second end, whereby the biased surface 17 is situated on the hexagonal part of arbor body 2, adjacent to locking member 13. However, in other embodiments, the biased surface might as well be situated on other areas of the arbor body.

According to the invention, the at least one adjustable locking member engages the at least one biased surface when the locking member is moved in a direction towards tne arbor Joo y an pusnes the thrust member towards the second end of the arbor body. In the preferred embodiment shown in Fig. 2, biased surface 17 is arranged in such a way that when locking member 13 is moved towards the arbor body, thrust member 7 is pushed towards the tool 5, whereby thrust member 7 is in the working position abutting tool 5 being installed on the threaded part 4 of arbor body 2 , and locking members 12 being engaged in the respective openings in tool 5 for transferring rotational force from the drilling machine to the tool 5. Thus thrust member 7 is further pushed against tool 5, whereby slack in the thread 4 is further eliminated and the arbor 2 is in a locked working position.

In the preferred embodiments of an arbor body 2 shown in Fig. 2 and 4B, the biased surface being engaged by the locking member is part of a conical hollow 19 which center axis is slightly displaced with respect to the working position towards that end of arbor body 2 on which the tool is installed.

The tool is mounted by screwing the threaded hole 6 of the rotating tool 5 onto the threaded portion 4 of arbor body 2 until it reaches the hexagonal portion 22 of arbor body 2. At the same time locking member is in the release position. Then locking member 7 is pushed towards the working position and driving pins 12 are aligned with the mating holes in tool 5 by twisting tool 5 to an appropriate position. The working position of thrust member 7 is such that the thrust member abuts tool 5 and exerts a certain pressure on the threaded hole 6 and the threaded portion 4, thus eliminating thread slack, offering the above mentioned advantages.

Figures 3A and 3B illustrate an adaptor for mounting a rotating tool in a drilling machine according to another preferred embodiment of the present invention. The preferred embodiments shown in Figures 3 to 8 are more compact than that shown in Figure 2. In addition to the embodiment shown in Figure 2 , a threaded locking means for the drill 16 is shown. Drill locking means 20 housed in a threaded hole 21, preferably in the hexagonal part 22 of arbor body 2 according to Fig. 4A. Drill 16 is inserted into a central bore 23 in arbor body 2 and locked by moving drill locking means 20 towards the center of arbor body 2 and pushing it against drill 16. The Arbor shown in Fig. 3A has the thrust member 7 in the release position. In this position, drill locking member 20 is tightened so that thrust member 7 fits over member 20 when being moved to the working position shown in Figure 3B. Thus drill locking member 20 is secured when thrust member 7 is moved to the working position.

Figs. 7A to 7D show different perspective views of the thrust member 7 according to the preferred embodiment shown in Figs. 3A and 3B.

In Fig. 8A a thrust member 7 with two locking members 13 is illustrated. When having two or more locking members, it is possible to center the locking member 13 more accurately around arbor body 2 and further increase the pressure on the abutting tool and/or accuracy of the locked working position. Preferably the locking members are arranged around the circumference of thrust member 7 with an angle between the locking members of 360 degrees/total number of locking members, i.e. 180 degrees for two members, 120 degrees for three members, etc.

Locking member 13 shown in Figure 8A further has an outer gripping area for manually moving locking member 13. Such an outer gripping area is preferably combined with e.g. a hexagon socket or torx in the head of locking member 13 , whereby locking member 13 can quickly be moved towards its locking position exerting a certain pressure, which is sufficient for locking and pushing thrust member towards the abutting tool. For exerting further locking pressure, a tool is used with the above mentioned socket in the head of locking member 13.

In another embodiment, locking member 13 is of the quick lock type having two fixed positions. Thus the need for a locking tool is eliminated. In Fig. 8B, a thrust member 7 is shown with a threaded hole 14 and the locking member 13 not being directed towards the center of arbor body 2. Moreover, locking member 13 is in this embodiment directed towards a beveled groove 18, as mentioned above.

The arbor according to the invention offers the safety concept that, if locking member 13 fails (loosens) and the locked working position is released, the ordinary working position still acts as a fallback reserve, and the tool will not loosen.

The arbor according to the invention eliminates the need for cumbersome tools, like large wrenches, to lock / unlock the thrust member. Instead, the locking member is lockable manually by hand or with the help of a tiny tool like an alien key wrench.

It should be emphasised that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof and said term does not exclude other elements or steps, whereas the terms "a" and "an" do not exclude a plurality and a single unit may fulfil the functions of several of the units recited in the claims . The present invention has been described above with reference to specific embodiments. However, other embodiments than the preferred above are equally possible within the scope of the appended claims, e.g. different shapes than e.g. the partially hexagonal of the arbor body and/or shapes and/or positions of the locking member, and/or instead of the described quick lock having two positions, the locking member can in a spring loaded way be pushed against the abutting tool, etc.

Claims

1. An adaptor (1) for mounting a rotating tool (5) in a drilling machine comprising: an arbor body (2) having a first end with a shank (3) 5 for mounting to a drill chuck, and a second end with a thread (4) for mounting the tool, a thrust member (7) arranged on the arbor body, said thrust member being movable in an axial direction but not in a rotational direction relative the arbor body (2) , 0 at least one driving pin (12) being fixed to the thrust member (7) and directed towards the second end of the arbor body for engaging the tool, characterized by at least one adjustable locking member (13) arranged in the thrust member (7) and movable in a direction 5 substantially perpendicular to the longitudinal axis of the arbor body (2) , at least one biased surface (17) arranged on the arbor body (2) adjacent to the adjustable locking member (13) , 0 wherein the at least one adjustable locking member

(13) engages the at least one biased surface (17) when the locking member (13) is moved in a direction towards the arbor body (2) and pushes the thrust member (7) towards the second end of the arbor body. 5

2. The adaptor according to claim 1, said thrust member (7) having a quick release means (10, 15) releasably defining a release position and a working position of said thrust member (7) , whereby the locking member (13) is ^~0^" engageaDle when said thrust member (7) is in said working position.

3. The adaptor according to claim 2, said release position and said working position respectively being defined by a spring loaded ball (10) in the thrust member (7) and by mating grooves (11) in said arbor body (2) .

4. The adaptor according to claims 1 to 3 , said biased surface (17) engaged by the locking member being part of a conical hollow (19) which center axis is slightly displaced with respect to the working position towards said second end.

5. The adaptor according to any of claims 1 to 4 , whereby the locking member (13) is rotatably arranged in the thrust member (7) .

6. The adaptor according to claim 5, the adjustable locking member (13) being a screw.

7. The adaptor according to any of claims 1 to 6, whereby the angle between neighboring locking members (13) is 360 degrees divided by the total number of locking members (13) .

8. The adaptor according to claims 1 to 7 , characterized in that the locking member (13) is moved in a direction towards the center of said arbor body (2) when the locking member is moved towards the arbor body (2) .

9. The adaptor according to claim 1, said adjustable locking member (13) being a quick lock.

^" 10. The adaptor according to claims 1 to 7, the biased surface (17) being a beveled groove arranged in a rotational direction around the longitudinal axis of arbor body (2) .

11. The adaptor according to any of the preceding claims, said locking member (13) being manually operable.

12. The adaptor according to any of the preceding claims, characterized in that the tool (5) is a hole saw.