Core drilling machine and a handle assembly for a core drilling machine

The present invention relates to a core drilling machine (100). The core drilling machine (100) includes a front housing part (102) including a protruding nose. The drilling machine (100) includes a front handle assembly (118) and an output drive shaft (110) projecting outward from the protruding nose. A fluid attachment ring (120) is rotably arranged around the protruding nose. Further, the front handle assembly (118) is arranged around the protruding nose.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage entry of PCT/SE2010/050411, which was filed on Apr. 16, 2010, said application is expressly incorporated herein its entirety.

TECHNICAL FIELD

The present invention relates to a core drilling machine comprising:a front housing part comprising a protruding nose;a front handle assembly;an output drive shaft projecting outward from the protruding nose;a detachable drill bit tool fastened to the output drive shaft; anda fluid attachment ring rotatably arranged around the protruding nose

BACKGROUND

Core drilling machines are widely used in order to make holes in bricks, concrete or the like. The core drilling machines may find applications in walls, roofs, floors and rocks also. The core drilling machine includes a drive shaft which is configured to hold a required drill bit tool based on applications. Further, a wet cooling arrangement can be provided to regularly lubricate the drill bit tool by water and/or lubricant. The cooling arrangement can include a water tube connected to a fluid attachment ring which is provided around the drive shaft. DE 19647575 has this, and further a fixed front handle near the rear handle. This however provides an unfavourably short distance between the front and rear handle, a distinct disadvantage.

Normally, a core drilling machine without a water lubricating arrangement is provided with handles at front and rear sections to aid manual gripping by an operator. The front handle assembly at the front section is provided to support the core drilling machine during operation. However, the front handle assembly is often fixed and may provide a hindrance to the operator to maneuver the core drilling machine, while operating. This may lead to other ergonomic problems such as inconveniency in work while changing an inclination of the core drilling from one angle to another angle. Thus, a fixed front handle assembly may pose problems for the operator to work with a core drilling machine.

Hence, there is a need for an improved front handle assembly for a core drilling machine, which provides a better handling of the core drilling machine without interfering with a cooling arrangement.

BRIEF DISCLOSURE OF THE INVENTION

In light of the aforementioned, it is an objective to solve or at least reduce the problem discussed above. In particular, the objective is to provide an improved front handle assembly for a core drilling machine.

The objective is achieved with a novel core drilling machine according to claim1. The core drilling machine includes a front housing part. Further, the first housing part includes a protruding nose. The drilling device further includes a front handle assembly and an output drive shaft. The output drive shaft is projected outwards from the protruding nose of the front housing part. Further, the drilling device includes a detachable drill bit tool, which is fastened to the output drive shaft. The drilling device also includes a fluid attachment ring which is rotatably arranged around the protruding nose. In an aspect of the present invention, a front handle assembly is arranged around the protruding nose, and is preferably rotatably arranged. Therefore the front handle assembly may relatively rotate about the fluid attachment ring to allow easy maneuvering of the core drilling machine. The advantage of a fluid attachment is combined with a front handle placed far forward being rotably adjustable in relation to the fluid supply.

According to claim2, the front handle assembly further includes a front handle and a front handle support. Further, according to claim3, the front handle includes a hand grip and a handle screw. The handle screw protrudes from an inner end of the hand grip and is rotatably fixed to the hand grip. In an aspect of the present invention, the handle screw may be screwed into a thread provided in the front handle support. The front handle may be tightened in the thread to attach and may be loosed to detach the front handle from the front handle support.

According to claim4, an inner end of the handle screw when screwed by the hand grip is arranged t6come into contact with the fluid attachment ring via a multiple protective bodies. The front handle may be locked with the fluid attachment ring and the protruding nose.

According to claim5, the front handle support also includes a front ring section. Further, the front ring section is located in front of the fluid attachment ring. Further, according to claim6, the front handle support includes a rear ring section such that, the rear ring section is located behind the fluid attachment ring.

According to claim7, the front handle support and the rear ring section are in contact to provide radial support for the front handle support. According to claim8, the rear ring section also includes an aperture. According to claim9, the front handle support includes a protruding section. Further, the protruding section may extend through the aperture of the rear ring section.

According to claim10, the front housing part is connected to a rear housing part via an intermediate housing part.

According to claim11, the detachable drill bit tool may include at least one cutting edge comprising diamonds.

According to claim12, the core drilling machine is a concrete drilling machine.

Claim13describes a front handle assembly for the core drilling machine. The front handle assembly may include a front handle support and a front handle connected with the front handle support. The front handle assembly further includes a front ring section. The front ring section is radially holding a front end of the front handle support. The front handle assembly also includes a rear ring section. The rear ring section is provided in contact with a rear end of the front handle support. In an aspect of the present invention, the front handle support and the rear ring section are in contact to create radial support for the front handle support.

According to claim14, the rear ring section may include an aperture. Further, according to claim15, the front handle support may include a protruding section. The protruding section may extend through the aperture of the rear ring section.

DESCRIPTION OF EMBODIMENTS

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of the invention incorporating one or more aspects of the present invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. For example, one or more aspects of the present invention can be utilized in other embodiments and even other types of devices. In the drawings, like numbers refer to like elements.

FIG. 1shows a perspective view of an exemplary core drilling machine100, in accordance with an embodiment of the present invention. In an embodiment of the present invention, the core drilling machine100may be used in concrete drilling application. However, it should be understood that the present invention could be incorporated into any suitable type of hand-held machine, for example, but not limited to, rotary cutter, handheld drill hammers etc. and is not limited to use merely in concrete drilling. In addition, any suitable size, shape or type of elements or materials could be used.

The core drilling machine100, as shown in theFIG. 1, includes a housing which may be structured into multiple parts. In an embodiment of the present invention, the housing may include a front housing part102and a rear housing part104. In another embodiment of the present invention, the front housing part102is connected to the rear housing part104via an intermediate housing part106. The intermediate housing part106may include an input means to set and control the torque and/or speed of the core drilling machine100. Further, it may be apparent to a person skilled in art, that the core drilling machine100may include a single integral housing.

In an embodiment of the present invention, the front housing part102may include a protruding nose108(shown inFIG. 2). The protruding nose108may extend in a forward direction of the front housing part102. The rear housing part104may include a prime mover (not shown) such as, but not limned to, an electric motor for driving the core drilling machine100. In an embodiment of the present invention, the electric motor may be drivably connected to an output drive shaft110via a suitable transmission assembly such as, but not limited to, gear, belts or a combination of these. The output drive shaft110may project outward from the protruding nose108and a detachable drill bit tool (not shown) may fasten to the output drive shaft110. In various embodiments of the present invention, the output drive shaft110may be made of spring steel so that it can be flexed while drilling without breaking. However, the output drive shaft110may be made of any other material, for example, but not limited to, hardened steel.

The rear housing part104may include a rear handle112to assist manual gripping of the core drilling machine100during operation. The front housing part102of the core drilling machine100may include a torque/speed regulator114. The rear handle112may also have a pulse trigger116to start and stop the operation of the core drilling machine100. Further, the core drilling machine100may include a front handle assembly118and a fluid attachment ring120. In an embodiment of the present invention, the front handle assembly118and the fluid attachment ring120may be both rotatably arranged around the protruding nose108.

In various embodiment of the present invention, the drill bit tool may include a diamond cutter and a cutting tool with a plurality of cutting edges. During operation, in order to cool the drill bit tool and the output drive shaft110, the fluid attachment ring120may be connected to a coolant tube (not shown) via a hose connector122. The hose connector122may be integrally provided with the fluid attachment ring120. The coolant tube may supply water and/or lubricant to cool the output drive shaft110and the drill bit tool during operation. The connector122can alternatively connect an adaptor for a vacuum cleaner to suck away dust.

In an embodiment of the present invention, the front handle assembly118may include a front handle124and a front handle support126. Further, the front handle124may include a hand grip128to assist a tight griping of the core drilling machine100in addition to the rear handle112. Further, a press fit arrangement of the front handle assembly118secured with the front housing part102.

FIG. 2illustrates an exploded view of the front handle assembly118of the core drilling machine100. As shown inFIG. 2, the front handle124includes a handle screw130and a spacer132, such that the handle screw130is rotatably fixed to the hand grip128and protrudes from an inner end of the hand grip128. Corresponding to the handle screw130, a thread134is provided in the front handle support126. During assembly, the thread134may receive the handle screw130by rotating the front handle124and may detach by loosing the handle screw130. Further, in an assembled state, the handle screw130comes in contact with the fluid attachment ring120preferably via multiple protective bodies136and138. A spring162, e,g, of steel or an elastomeric material, e,g, rubber, in the front handle124is compressed by the spacer132when the hand grip128is screwed via handle screw130such that protective bodies136and138are pressed harder and harder towards the fluid attachment ring120when the handgrip is screwed more and more. This provides a very stiff attachment of the handgrip128. In an embodiment of the present invention, the protective bodies136and138may be made of an elastomeric material (e.g. rubber), steel or plastic. When screwing the handgrip128both the front handle and the fluid attachment ring120are locked not to rotate around the protruding nose108. They are therefore also locked in relation to eachother, and in a selected position. This is very favorable for the operator.

In an embodiment of the present invention, the front handle support126may include a front ring section140. The front ring section140may be located in front of the fluid attachment ring120. The front ring section140may be an integral part of the front handle support126and in the assembled state, the front ring section140radially holds the front handle support126. Further, the front ring section140may be configured to receive a lock ring142into the front ring section140. In an embodiment of the present invention, the lock ring142may also be made of some lighter material such as plastic.

In an embodiment of the present invention, the front handle support126may include a rear ring section144, such that the rear ring section144is located behind the fluid attachment ring120. Further, the front handle support126includes a protruding section146which is configure to be received in an aperture148provided in the rear ring section144.

FIG. 3shows a cross-sectional view of the front handle assembly118, in accordance with an embodiment of the present invention. As shown in theFIG. 3, in an embodiment of the present invention, the output drive shaft110may be supported on a bearing150. During operation, the bearing150may reduce wear of the output drive shaft110. Further, a leak indicating passage152is provided to indicate a water leak in the sealing154during operation.

Moreover, multiple sealing members154are provided between the output drive shaft110and a sleeve156. The sealing members154may provide a leak proof passage for the coolant within the output drive shaft110. The sleeve156may also include a protruding part, such that the protruding part is received in a groove provided on the protruding nose108.

Additionally, a circular clip158also supports the sleeve156. Further an0-rings160is disposed between the fluid attachment ring120and the protruding nose108. The O-rings160may be a compressed seal, between the fluid attachment ring120and the protruding nose108. However, any other sealing means (e.g. face seal, lip seal etc.) may be utilized without departing from the essence of the present invention.

FIG. 4shows another cross-sectional view of the front handle assembly118, in accordance to the present invention. The front handle118is rotatable around the fluid attachment ring120when required. In an embodiment of the present invention, the rotation of the front handle118may be provided with an orientation of about256degrees around the fluid attachment ring120. This limited orientation of front handle118may permit rotation of the front handle124around the fluid attachment ring120without interfering with the cooling arrangement. Further, the present invention may advantageously facilitate an improved separate lock for the front handle124and the cooling tube (not shown) simultaneously. In addition to that, the present invention may permit a better handling of the core drilling machine100and may also allow the operator to improve the work efficiency.