Core hole drilling device

Abstract

The invention relates to a core hole drilling device (100) with a sawing element (120) and a ram (150) suitable for ejecting a saw core (190). The sawing element (120) and the ram (150) are arranged on a drive spindle (110) provided with an external thread (114) and can be coupled to one another for a sawing operation by means of a respective coupling device (140, 152) and can be uncoupled from one another for ejecting the saw core (190). The invention is characterized in that at least one element (140) of the coupling device is acted upon by at least one spring (180) during coupling and / or uncoupling, and at least one of the elements (140) of the coupling device has axial mobility parallel to an axis (A) of the drive spindle (110) in the amount of the spring travel of the spring (180).

Description

TECHNICAL FIELD

[0001] The present invention relates to a core hole drilling device, also known as a “hole saw”, with a device for ejecting a drill core. STATE OF THE ART

[0002] US 5082403 A discloses a core drilling device in which a single drive actuates both the sawing element, which cuts a circular core from a work material, and a ram for ejecting the core from the sawing element after the sawing process has been completed. The ram and sawing element are coupled together by means of a coupling device during the sawing process and are uncoupled from each other to eject the core or work material core from the sawing element. The coupling device consists of two facing discs with oppositely inclined bevels that end at a vertical engagement edge. Uncoupling is difficult in the known embodiment, and due to frequent sliding against one another and the small number of engagement edges, the known coupling device is prone to premature wear.

[0003] From US 2010 / 0047030 A1 a core hole drilling device is known in which an axially movable ejector plate is spring-loaded in the direction of expulsion of the drill core by means of a spring.

[0004] Based on the above-mentioned prior art, it is the object of the present invention to provide a core hole drilling device in which an improved coupling device ensures reliable, low-wear coupling and uncoupling of the saw element and the ram. DISCLOSURE OF THE INVENTION

[0005] The object is achieved with a core hole drilling device according to claim 1. Further developments of the invention are the subject of the dependent claims.

[0006] According to the invention, a core hole drilling device is characterized in that at least one element of the coupling device is acted upon by at least one spring during coupling and / or uncoupling, and at least one of the elements of the coupling device has axial mobility parallel to an axis of the drive spindle equal to the spring travel of the spring. The spring ensures a defined position of the elements of the coupling device after completion of the sawing process, even when working overhead.

[0007] The coupling device has at least one gearing or driver with a toothing acting parallel to the axis of the drive spindle. However, it is preferred that the coupling device has at least two and preferably even three or more such gearings or drivers, particularly preferably even six to eight gearings or drivers. The multiple engagements better distribute the load during power transmission and significantly reduce wear on the coupling device.

[0008] In a preferred embodiment of the present invention, the at least one spring is designed as a compression spring. Such a compression spring can be arranged in a space-saving manner in the area of ​​the coupling device.

[0009] Particularly preferred is a coupling device which is formed by two coupling discs, of which one coupling disc is connected in a rotationally fixed manner to the saw element and the other coupling disc is connected in a rotationally fixed manner to the ram.

[0010] According to an alternative, it is provided that the clutch device is formed by a clutch disc and at least one rocker arm provided with a driver, of which either the clutch disc is connected in a rotationally fixed manner to the sawing element and the rocker arm is connected in a rotationally fixed manner to the tappet or, conversely, the rocker arm is connected in a rotationally fixed manner to the tappet and the clutch disc is connected to the sawing element.

[0011] According to a further advantageous embodiment of the alternative of the invention, it is provided that the rocker arm can be acted upon by means of a spring on a pressure piece opposite the driver in the direction of decoupling of the driver.

[0012] It is particularly advantageous that the drive spindle can be operated in different directions of rotation for the sawing process or for ejecting the saw core.

[0013] It is also advantageous that the saw element can be manually fixed to decouple the ram. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Further features, advantages, and embodiments of the invention will become apparent from the following description of embodiments of a core hole drilling device based on the figures. It shows: Fig. 1 a longitudinal section through a first embodiment of a core hole drilling device, Fig. 2 a plan view of the first embodiment according to Fig. 1, Fig. 3 a perspective side view of the first embodiment according to Fig. 1, Fig. 4 an enlarged detailed view of a coupling carrier of the first embodiment, Fig. 5 a longitudinal section through the coupling carrier according to Fig. 4, Fig. 6 is a plan view of a clutch disc of the first embodiment, Fig. 7 a longitudinal section through the clutch disc according to Fig. 6, Fig. 8 is a plan view of the coupling device on the top side of the plunger of the first embodiment, Fig. 9 a longitudinal section through the tappet according to Fig. 8; Fig. 10 is a representation of a second embodiment of a core hole drilling device, Fig. 11 a longitudinal section through the second embodiment according to Fig. 10, Fig. 12 is a plan view of a saw blade holder of the second embodiment, Fig. 13 is a plan view of a clutch disc of the second embodiment, and Fig. 14 a longitudinal section through the clutch disc according to Fig. 13. EMBODIMENTS OF THE INVENTION

[0015] The Fig. 1 to 9 show a first embodiment of a core hole drilling device 100 according to the invention with a drive spindle 110, the upper end of which is designed as a tool holder 112. As the Fig. 2 and Fig. 3, the tool holder 112 is preferably designed as a triangular profile and can thus be accommodated in the drill chuck of any conventional drill.

[0016] The drive spindle 110 is provided with an external thread 114 in the area adjacent to the tool holder 112. The external thread 114 is designed, for example, as a trapezoidal thread with a pitch of preferably approximately 4 mm to 6 mm per thread turn.

[0017] In the upper region of the external thread 114, a stop 170 is arranged on the drive spindle 110, the position of which can be adjusted. For example, the stop 170 is fastened by means of a screw 174, which can preferably be fixed in a threaded bore 172 of the stop 170 running transversely to an axis A of the drive spindle 110. The height-adjustable fixation of the stop 170 allows both adaptation to the thickness of the material to be drilled or sawn, as well as readjustment after resharpening a saw blade 122 (described below) due to its wear from frequent use. The stop 170 is preferably made of a damping rubber or plastic material, at least in its lower part.

[0018] A plunger 150 is attached to the drive spindle 110 in the lower area of ​​the external thread 114. The plunger 150 is preferably permanently attached to the drive spindle 110, for example, by welding or gluing, but can also be detachably attached.

[0019] The drive spindle 110 has a drill holder 116 on its underside, which serves to accommodate an optionally insertable center drill 160. The center drill 160 can be fixed, for example, by means of a fixing screw 158, which can be screwed into a threaded bore 156 arranged transversely to the axis A of the drive spindle 110 in the plunger 150. The fixing screw 158 can simultaneously serve to fasten the plunger 150 to the drive spindle 110.

[0020] On its upper side, the tappet 150 has a clutch disc 152 which is provided with an upwardly acting toothing 153. The toothing 153 is shown in an enlarged view in connection with the Fig. 8 and Fig. 9 explained.

[0021] Between the stop 170 and the plunger 150, a coupling carrier 130 is arranged on the drive spindle 110, which has an internal thread 132 that engages with the external thread 114 of the drive spindle 110.

[0022] A holder 126 of a saw element 120 is preferably connected to the coupling carrier 130 via several screws 134. As can be seen from Fig. 2, for example, three such screws 134 are provided, evenly distributed around the circumference of the coupling carrier 130. The screws 134 engage in corresponding internal threads 127 on the holder 126. The saw element 120, which is pot-shaped in conjunction with the holder 126, has a hollow cylindrical saw blade 122, which forms a circumferential cutting edge 124 on its lower, open side. In the illustrated embodiment, which is especially suitable for hollow fiber insulation, the cutting edge 124 is wave-shaped, but can also be designed differently for other materials, for example, sawtooth-shaped.

[0023] Furthermore, one or more guide bodies are provided on the clutch carrier 130 for guiding the clutch disc 140 relative to the clutch carrier 130. For example, several guide pins 138 can be provided as guide bodies, the shafts of which are slidably guided in bores 136 of the clutch carrier 130. The lower end of the guide pins 138 is provided, for example, with an external thread, which is screwed into a threaded bore 144 of a clutch disc 140. As can be seen from Fig. 2, three such guide pins 136 can be provided evenly distributed around the circumference of the coupling carrier 130.

[0024] The clutch disc 140 preferably surrounds a collar 131 of the clutch carrier 130 with an inner recess. Furthermore, the clutch disc 140 is preferably movably mounted with its outer circumference in a recess 128 of the holder 126 parallel to an axis A of the drive spindle 110 by means of the guide pins 138. This axial movement occurs against the pressure of at least one spring 180. The spring 180 can, for example, be arranged surrounding the collar 131 between the underside of the clutch carrier 130 and the top side of the clutch disc 140.

[0025] The clutch disc 140 has a toothing 141 on its underside. The toothing is preferably - as can be seen from the enlarged illustration in Fig. 6 and Fig. 7 - is formed from several gently rising inclined surfaces 142 and from these steeply sloping stop surfaces 143.

[0026] The toothing 141 of the clutch disc 140 serves to engage with the toothing 153 of the clutch disc 152 on the tappet 150. The toothing 153 has an equal number of inclined surfaces 154 inclined in opposite directions with respect to the inclined surfaces 142, the raised ends of which merge into steeply sloping stop surfaces 155. Preferably, three or more, particularly preferably even six to eight such toothings 153 and stop surfaces 155 are arranged evenly distributed around the circumference of the clutch discs 140 and 152, respectively.

[0027] When the clutch discs 140 and 152 are coupled, the stop surfaces 143 and 155 engage tightly with each other, creating a rotationally fixed connection between the plunger 150, which is firmly connected to the drive spindle 110, and the saw element 120. When the clutch discs 140 and 152 are coupled, the inclined surfaces 142 and 154 slide against each other under the load of the spring 180 until the stop surfaces 143 and 154 engage with each other.

[0028] The clutch discs 140 and 152, together with their stop surfaces 143 and 155, form a “clutch device” within the meaning of the main claim of this patent application, wherein the clutch discs 140 and 152 and the stop surfaces 143 and 155 are also referred to as “elements” of this clutch device.

[0029] Like the Fig. 6 and Fig. 8, preferably a plurality of inclined surfaces 142 or 154 and stop surfaces 143 or 155 are provided on the clutch discs 140 or 152. In the exemplary embodiment shown, there are six such inclined surfaces 142 or 154 and stop surfaces 143 or 155. The plurality of inclined surfaces 142 or 154 and stop surfaces 143 or 155 ensures wear-resistant coupling and decoupling of the clutch discs 140 or 152 and optimal power transmission from the drive spindle 110 via the ram 150 to the saw element 120. In any case, at least two, preferably three or more inclined surfaces 142 or 154 and stop surfaces 143 or 155 should be provided on the clutch discs 140 or 152.

[0030] The function of the first embodiment is described below. In a basic position before the start of a sawing operation, the ram 150 is moved fully upward relative to the sawing element 120, so that the toothing 153 of the clutch disc 152 engages the toothing 141 on the clutch disc 140. This basic position is achieved after a preceding sawing operation with subsequent actuation of the ram 150 to expel the drill core 190 by clockwise rotation of the drive spindle 110 with the saw blade 122 attached. In this case, the external thread 114 of the drive spindle 110 is screwed upwards through the internal thread 132 on the clutch carrier 130 until the teeth 153 on the lower clutch disc 152 engage with the teeth 141 on the upper clutch disc 140 via the sliding of the inclined surfaces 154 and 142 on one another under compression of the spring 180.

[0031] To operate the drive spindle 110, the tool holder 112 is clamped into the chuck of a commercially available drill (not shown), and the saw element 120 is placed on the material to be drilled—optionally with the assistance of the center drill 160, which is positioned slightly downward. This material can be, for example, a wood fiber insulation board with a thickness of approximately 40-120 mm, such as is used for roof insulation. The holes drilled by the saw element 120 serve to additionally backfill with insulation material, which is blown into the cavities behind the wood fiber board through the holes exposed by the saw element 120.

[0032] To cut out the core 190 from the wood fiberboard material, the drill is set to clockwise rotation, for example, with the saw blade 122 slowly working its way through the material with the cutting edge 124. The length of the saw blade 122 is adapted to the thickness of the material to be drilled. As soon as the saw blade 122 has worked its way through the material, the sawing process is stopped and the drill is switched to counterclockwise rotation, with one of the operator's hands simultaneously holding the upper part of the saw element 120 from the outside. By holding the saw element 120 and reversing the direction of rotation of the drill, the gears 141 and 153 on the clutch discs 140 and 152, respectively, are disengaged and the plunger 150 is screwed downwards by the drive spindle 110 through the engagement of the external thread 114 into the internal thread 132 of the clutch carrier 130 held together with the saw element 120.The underside of the ram 150 pushes the drill core 190 with its upper side up to the height shown in . Fig. 1. Thus, the core sample 190 protrudes largely from the saw blade 122 and can be removed from the saw blade 122 by a simple turning and pulling movement by hand. Because the ram stroke line 159 is positioned slightly above the cutting edge 124, the core sample 190 does not fall to the ground in an uncontrolled manner, but can be removed in a controlled manner by the operator.

[0033] The stop 170, which is adjustable by means of the screws 174 relative to the drive spindle 112, limits the path of the ram 150 when ejecting the drill core 190 and thus defines the ram stroke line 159. In Fig. 1, a vertical distance H1 is shown between the stop 170 and the top of the clutch carrier 130. Furthermore, a vertical distance H2 is shown between the underside of the clutch disc 140 and the top of the clutch disc 152. The dimensions H1 and H2 shown there are not exactly relevant, since the distance H1 should correspond to the vertical distance H3 that the underside of the tappet 150 travels until it reaches the tappet stroke line 159. The sum of the distances H2 plus H3, i.e., the entire distance of the tappet 150 from its removal from the upper clutch disc 140 until it reaches the tappet stroke line 159, is advantageously somewhat less than the thickness D190 of the core sample 190.

[0034] The spring 180 ensures secure engagement of the gears 141 and 153 during the sawing process. At the end of the sawing process and when the sawing element 120 is uncoupled from the ram 150, the upper clutch disc 140 can move upwards against the pressure of the spring 180 so far that the gears 141 and 153 can quickly disengage in less than one revolution of the drive spindle 110, so that the wear on the gears 141 and 153 can be kept to a minimum.

[0035] The Fig. 10 to 14 show a second embodiment of a core hole drilling device 200 according to the invention. In this embodiment, identical or similar components are provided with a reference number 100 higher than in the first embodiment.

[0036] The core hole drilling device 200 has a drive spindle 210, at the upper end of which a tool holder 212 is preferably designed in the shape of a triangle, which can be received by a drill chuck of a conventional drilling machine (not shown).

[0037] The drive spindle 210 has an external thread 214, which is designed in particular as a trapezoidal thread with a pitch of preferably approximately 4 mm to 6 mm per thread turn.

[0038] In the upper part of the external thread 214, a stop 270 is attached to the drive spindle 210, adjoining the tool holder 212 downwards. The stop 270 is preferably made of a damping rubber or plastic material, at least in the lower part. The stop 270 further has, for example, in the upper part, a transversely extending threaded bore 272, which serves to receive at least one screw 274, preferably designed as a grub screw. The screw 274 allows the stop 270 to be adjusted in height and releasably secured to the drive spindle 210.

[0039] A blind hole-like drill holder 216 is formed centrally on the underside of the drive spindle 210.

[0040] A plunger 250 is attached to the lower portion of the drive spindle 210. The plunger is preferably provided with a horizontally extending threaded bore 256 extending to the drill bit receptacle 216 in the drive spindle 210. The threaded bore 256 serves to receive a fixing screw 258, preferably designed as a grub screw. The fixing screw 258 can be used to fasten both the center drill 260 and the plunger 250 to the drive spindle 210. Alternatively, the plunger 250 can also be permanently connected to the lower end of the drive spindle 210 by welding or gluing.

[0041] The plunger 250 simultaneously forms a clutch disc 252 on its upper side, which is provided with at least one upwardly projecting stop surface 255. Preferably, at least two or more such stop surfaces 255 are provided.

[0042] A clutch disc 240 is screwed onto the external thread 214 of the drive spindle 210 with an internal thread 242. The clutch disc can be designed as a flat disc with a centrally upwardly projecting collar 249. A holder 226 of a saw element 220 is preferably attached to the upper side of the clutch disc 240, surrounding the collar 249. The holder 226 is attached to the clutch disc 240, for example, as shown in Fig. 12 - by means of several, in particular three screws 234, which are screwed into threaded holes 227 on the clutch disc 240.

[0043] The saw element 220 has a pot-shaped saw blade 222 that opens downwards and is non-rotatably connected to the holder 226. A cutting edge 224 is formed on the underside of the saw blade 222. The cutting edge 224 serves to saw out a circular drill core 290, for example, from a wood fiberboard, as already described in connection with the first embodiment.

[0044] On the underside of the clutch disc 240, a plurality of coupling elements, for example designed as rocker arms 246, are preferably formed.

[0045] For this purpose, a plurality of downwardly projecting bearing blocks 244 can be arranged on the underside of the clutch disc 240, the number of which corresponds to the number of stop surfaces 255 on the lower clutch disc 252. Each bearing block 244 has, for example, a bearing bore 241, which serves to receive a bearing pin 245, by means of which the rocker arm 246 is pivotally attached to the bearing block 244.

[0046] Each of the rocker arms 246 has a downwardly projecting thrust piece 247 at one end, in particular an inner end, and a downwardly projecting driver 248 at one end, in particular an outer end. The rocker arm 246 is preferably mounted on the bearing pin 245 such that the distance from the bearing pin 245 to the thrust piece 247 is approximately 1 / 3, and the distance from the bearing pin 245 to the driver 248 is approximately 2 / 3 of the total length of the rocker arm 246.

[0047] The upper side of the pressure piece 247 is subjected to spring pressure, for example, by a spring 280 mounted in a recess on the underside of the clutch disc 240. The rocker arm 246 is pressed by the spring 280 with the pressure piece 247 onto the upper side of the clutch disc 252, whereby the driver 248 at the outer end of the rocker arm 246 is simultaneously pivoted upward into a disengaged position with the stop surface 255 on the lower clutch disc 252.

[0048] The clutch discs 240 and 252, as well as the rocker arms 246 with the drivers 248 and the stop surfaces 255 together form a “clutch device” within the meaning of the main claim of this patent application, wherein the clutch disc 240, rocker arm 246, driver 248, clutch disc 252 and stop surfaces 255 are also referred to as “elements” of this clutch device.

[0049] The function of the second embodiment is described below. In the basic position, the clutch discs 240 and 252 rest against each other, with the upper side of the lower clutch disc 252 pressing the pressure piece 247 of the rocker arm 246 upward against the spring 280, and the driver 248 pivoting downward accordingly and engaging the stop surface 255 on the lower clutch disc 252 to transmit a rotary movement.

[0050] The tool holder 212 is fixed in the chuck of a drill (not shown). The tip of the center drill 260 is positioned on the fiberboard according to the intended hole, and the drive spindle 212 is set in motion, for example, by rotating the drill clockwise. Through the coupling of the drivers 248 and the stop surfaces 255, the rotary motion of the drive spindle 210 is transferred from the lower clutch disc 252 to the upper clutch disc 240, and through the latter's connection to the holder 226, to the saw element 220. The saw blade 222 cuts into the fiberboard material with its cutting edge 224.The springs 280 ensure that the rocker arms 246 are not engaged with their drivers 248 solely by gravity - due to the longer and thus heavier lever arm of the rocker arm 246 on the driver 248 side - but only when the lower clutch disc 252 is pressed against the pressure pieces 247. As soon as the pressure of the upper side of the lower clutch disc 252 against the pressure piece 247 decreases during uncoupling, the springs 280 ensure a rapid and thus low-wear uncoupling of the drivers 248 from the stop surfaces 255, regardless of the working position of the core hole drilling device 200 (horizontal, overhead, or downward).

[0051] At the end of the sawing process, the core 290 initially sits in the circular saw blade 222 and is held by it. The operator now holds the upper part of the saw blade 222 with one hand and switches the drill to counterclockwise rotation. This causes the external thread 214 of the drive spindle 210 to screw through the internal thread 242 of the upper clutch disc 240, and the plunger 250 begins to move downward. As soon as the pressure piece 247 on the rocker arm 246 moves away from the upper surface of the lower clutch disc 252, the spring 280 presses the pressure piece 247 downward, thereby simultaneously disengaging the driver 248 from the stop surfaces 255.Due to the asymmetrical division of the lever travel between the pressure piece 247 and the bearing pin 245, which is approximately 1 / 3 of the length of the rocker arm 246, and the lever travel between the bearing pin 245 and the driver 248, which is approximately 2 / 3 of the length of the rocker arm 246, the drivers 248 disengage from the stop surfaces 255 very quickly and with little friction when the saw element 220 is held and the direction of rotation of the drilling machine is reversed.

[0052] The ram 250 pushes the core 290 further downward until the stop 270 rests against the top of the holder 226 and the top of the core 290 has reached the ram stroke line 259. The core 290 then sits only loosely in the lowermost part of the saw blade 222 and can be removed from the saw blade 222 by the operator.

[0053] Regarding the adjustment of the stop 270 and the resulting limited total stroke of the ram 250, the same applies as described in connection with the first embodiment. The thickness of the drill core 290 is therefore slightly greater than the total stroke of the ram 250, so that the drill core 290 reaches the ram stroke line 259 with its upper side when pushed out and can thus be removed from the saw blade 122 in a controlled manner. LIST OF REFERENCE SYMBOLS 100 core hole drilling device (hole saw) 110 Drive spindle 112 tool holder (on 110) 114 external thread (on 110) 116 drill chuck 120 saw element 122 saw blade 124 cutting edge (at 122) 126 holders 127 threaded hole 128 recess 130 coupling carrier 131 Bund (to 130) 132 internal thread 134 Screw 136 bore 138 guide bolts 140 clutch disc 141 Gearing (on 140) 142 Inclined surface 143 Stop surface 144 threaded hole 150 pestles 152 clutch disc (on 150) 153 Gearing 154 Inclined surface 155 stop surface 156 threaded hole 158 Fixing screw 159 Ram stroke line 160 center drills 170 stops 172 threaded hole 174 Screw 180 spring 190 drill core (saw core) D190 thickness (of 190) H1 route (between 170 and 130) H2 route (between 140 and 152) H3 path (between 150 and 159) 200 core hole drilling device (hole saw) 210 drive spindle 212 tool holder (on 210) 214 external thread (on 210) 216 drill chuck 220 saw element 222 saw blade 224 cutting edge (at 222) 226 holders 227 threaded hole 234 screw 240 clutch disc 241 bearing bore 242 internal thread 244 bearing block 245 bearing bolts 246 rocker arms 247 pressure piece 248 drivers 249 Bund 250 pestles 252 clutch disc (on 250) 255 stop surface 256 threaded hole 258 Fixing screw 259 Ram stroke line 260 center drills 270 stops 272 threaded hole 274 screw 280 spring 290 drill core (saw core)

Claims

[1] Core hole drilling device (100; 200) with a sawing element (120; 220) and a ram (150; 250) suitable for ejecting a drill core (190; 290), wherein the sawing element (120; 220) and the ram (150; 250) are arranged on a drive spindle (110; 210) provided with an external thread (114; 214) and can be coupled to one another for a sawing process and uncoupled from one another for ejecting the drill core (190; 290) by means of a respective coupling device (140, 152; 240, 246), characterized by that at least one element (140; 246) of the coupling device (140, 152; 240, 246) is acted upon by means of at least one spring (180; 280) during coupling and / or uncoupling and at least one of the elements (140; 246) of the coupling device (140, 152; 240, 246) has an axial mobility parallel to an axis (A) of the drive spindle (110; 210) in the size of the spring travel of the spring (180; 280). [2] Core hole drilling device (100; 200) according to claim 1, characterized by that the coupling device (140, 152; 240, 246) has at least one toothing (141, 153) acting parallel to an axis of the drive spindle (110; 210) or a driver (248). [3] Core hole drilling device (100; 200) according to claim 2, characterized by that the toothing (141, 153) of the coupling device (140, 152; 240, 246) has at least two, preferably at least three, simultaneously effectively engageable stop surfaces (143, 155; 255) or drivers (248). [4] Core hole drilling device (100; 200) according to at least one of claims 1 to 3, characterized by that the at least one spring (180; 280) is designed as a compression spring. [5] Core hole drilling device (100) according to one of the preceding claims, characterized bythat the coupling device (140, 152) is formed by two coupling discs (140; 152), of which one coupling disc (140) is connected in a rotationally fixed manner to the saw element (120) and the other coupling disc (153) is connected in a rotationally fixed manner to the ram (150). [6] Core hole drilling device (200) according to one of claims 1 to 4, characterized by that the coupling device (240, 252) is formed by a coupling disc (252) and at least one rocker arm (246) provided with a driver (248), of which either the coupling disc (252) is connected in a rotationally fixed manner to the sawing element (220) and the rocker arm (246) is connected in a rotationally fixed manner to the tappet (250) or, conversely, the rocker arm (246) is connected in a rotationally fixed manner to the tappet (250) and the coupling disc (240) is connected to the sawing element (220). [7] Core hole drilling device (200) according to claim 6, characterized bythat the rocker arm (246) can be acted upon by means of a spring (280) on a pressure piece (247) opposite the driver (248) in the direction of decoupling the driver (248). [8] Core hole drilling device (100; 200) according to at least one of the preceding claims, characterized by that the drive spindle (110; 210) can be operated in different directions of rotation for the sawing process and for ejecting the drill core (190; 290). [9] Core hole drilling device (100; 200) according to one of the preceding claims, characterized by that the saw element (120; 220) can be manually fixed to uncouple the ram (150; 250). [10] Core hole drilling device (100; 200) according to one of the preceding claims, characterized by that the stroke (H2+H3) of the ram (150; 250) is slightly smaller than the thickness (D190) of the saw core (190; 290).

Images