LARSSON, Martin (Rävstigen 18, Öjersjö, S-433 50, SE)
CLAIMS
1. A drill stand (3) for a core drilling device having a core drill (1) and a drilling device (2) for rotating the core drill (1), said drill stand (3) including a base (4) adapted to be anchored to a floor, a wall, or fitted to a structure that in turn is anchored in a suitable manner, said drill stand (3) further including a column (5) having a normal position at right angles to the base (4), a shaft (6) by which one end of the column (5) is pivotally attached to the base (4), and means for adjusting an inclination of the pivotable column (4) in relation to the normal position, said drilling device (2) being mounted on the column (5) and movable there along toward and away from the base (4), c h a r a c t e r i z e d b y
- said base (4) having a bearing bracket (20) at each end of the shaft (6), each bearing bracket (20) having a cap portion (21) that can be tightened to lock the shaft (6) against rotation, and - said column (5) having one end operatively connected to a center portion of the shaft
(6) for pivotal movement around a pivotal axis of the shaft (6).
2. A drill stand as claimed in claim 1, wherein in each bearing bracket (20), a plain bearing bushing (23) for the shaft (6), said bushing having an axial split (24) along it to permit the tightening of the bearing bracket (20),
3. A drill stand as claimed in anyone of claim 1 or 2, wherein said column inclination adjusting means includes a clamping ring (25) mounted adjustably in a circumferential direction on the shaft (6), said clamping ring (25) having a portion (26) of inwardly reduced radial thickness, and where a stop member (27) projects from the base (4) into said ring portion (26) to restrict the pivotal movement of the column (5).
4. A drill stand as claimed in claim 3, wherein said ring portion (26) permits a pivotal movement on the order of 90°.
5. A drill stand as claimed in anyone of claim 1 to 4 wherein the shaft (6) is tubular.
6. A drill stand as claimed in anyone of claim 1 to 5, wherein one of the shaft (6) and the bearing bracket (20) has a first mark (31) indicating the normal position of the column (5) and the other has a scale (33) indicating the actual inclination of the column (5).
7. A drill stand as claimed in claim 3 and anyone of claim 4 to 6, wherein one of the clamping ring (25) and the bearing bracket (20) has a second mark (34) indicating the normal position of the column (5) and the other has a scale (35) indicating the actual inclination of the column (5) at which the clamping ring (25) restricts further inclination of the column (5).
8. A drill stand as claimed in anyone of claim 1 to 7, wherein the center portion of the shaft (6) has a laterally projecting generally cylindrical stud (36), to which the column (5) is detachably connected.
9. A drill stand as claimed in claim 8, wherein
- the generally cylindrical stud (36) has a bottom portion (37) attached to the shaft (6) and an intermediate portion (38) of reduced diameter having a circumferential groove (39),
- the column (5) has a tubular bottom portion (43) adapted to fit around the intermediate portion (38) of the generally cylindrical stud (36),
- a stop member (45) extends through the wall of the tubular bottom portion (43) of the column (5) and into the groove (39) to lock the column (5) at least axially to the shaft (6).
10. A drill stand as claimed in claim 9, wherein
- an indexing member (46) is provided on the bottom portion (37) of the stud (36), said indexing member (46) having a portion (47) projecting into the intermediate stud portion (38) of reduced diameter, and
- the tubular bottom portion (43) has a plurality of recesses (48) matching the projecting portion (47) of the indexing member (46).
11. A drill stand as claimed in claim 9, wherein at least three of the recesses (48) are spaced apart 90°.
12. A drill stand as claimed in claim 9, wherein the indexing member (46) can be inactivated.
13. A drill stand (3) for a core drilling device having a core drill (1) and a drilling device (2) for rotating the core drill (1), said drill stand (3) including a base (4) adapted to be anchored to a floor, a wall, or fitted to a structure that in turn is anchored in a suitable manner, said drill stand (3) further including a column (5) having a normal position at right angles to the base (4), a shaft (6) by which one end of the column (5) is attached to the base (4), said drilling device (2) being mounted on the column (5) and movable there along toward and away from the base (4), c h a r a c t e r i z e d b y
- the center portion of the shaft (6) has a laterally projecting generally cylindrical stud (36), to which the column (5) is detachably connected,
- the generally cylindrical stud (36) has a bottom portion (37) attached to the shaft (6) and an intermediate portion (38) of reduced diameter having a circumferential groove (39),
- the column (5) has a tubular bottom portion (43) adapted to fit around the intermediate portion (38) of the generally cylindrical stud (36),
- a stop member (45) extends through the wall of the tubular bottom portion (43) of the column (5) and into the groove (39) to lock the column (5) at least axially to the shaft (6),
- an indexing member (46) is provided on the bottom portion (37) of the stud (36), said indexing member (46) having a portion (47) projecting into the intermediate stud portion (38) of reduced diameter, and
- the tubular bottom portion (43) has a plurality of recesses (48) matching the projecting portion (47) of the indexing member (46).
14. A drill stand as claimed in claim 14, wherein said base (4) having a bearing bracket (20) at each end of the shaft (6), each bearing bracket (20) having a cap portion (21) that can be tightened to lock the shaft (6) against rotation.
15 . A drill stand as claimed in claim 14, wherein in each bearing bracket (20), a plain bearing bushing (23) for the shaft (6), said bushing having an axial split (24) along it to permit the tightening of the bearing bracket (20),
16. A drill stand as claimed in anyone of claim 14 or 15, wherein said column inclination adjusting means includes a clamping ring (25) mounted adjustably in a circumferential direction on the shaft (6), said clamping ring (25) having a portion (26) of inwardly reduced radial thickness, and where a stop member (27) projects from the base (4) into said ring portion (26) to restrict the pivotal movement of the column (5). |
A DRILL STAND FOR A CORE DRILLING DEVICE
DESCRIPTION
TECHNICAL FIELD
The present invention relates to a drill stand for a core-drilling device having a core drill and a drilling device for rotating the core drill, said drill stand including a base adapted to be anchored to a floor, a wall, or fitted to a structure that in turn is anchored in a suitable manner, said drill stand further including a column having a normal position at right angles to the base, a shaft by which one end of the column is pivotally attached to the base, and means for adjusting an inclination of the pivotable column in relation to the normal position, said drilling device being mounted on the column and movable there along toward and away from the base.
BACKGROUND ART
Core-drilling devices for coring concrete floors or walls, for example, are previously known and can have the column fixed to the base as disclosed in WO-Al 2005/095075 or pivotally attached to the base as disclosed in DE-Al 34 08 457 or in www.dimas.com/nodel269.asp, for example. The pivotal attachment of the column to the base is necessary when the bore through the floor or the wall is to form a predetermined angle with the plane of the floor or the wall, respectively. As a rule, the drill stand is anchored to the floor or the wall by means of an expansion bolt, and adjustment screws are used for leveling the base. If a plurality of bores is to be made, the core-drilling device has to be moved to a new location, and the drill stand has to be anchored and leveled and the possible inclination of the column checked for each one of the holes, even when the desired bores are located close to one another.
DISCLOSURE OF THE INVENTION
The main object of the present invention is increase the versatility of the drill stand, without sacrificing stability and low cost, hi accordance with the present invention, this object is achieved in a drill stand of the kind referred to in the introductory portion above, in that the
base has a bearing bracket at each end of the shaft, and each bearing bracket has a cap portion that can be tightened to lock the shaft against rotation, hi each bearing bracket there is a plain bearing bushing for the shaft and the bushing has an axial split along it to permit the tightening of the bearing bracket. The column has one end operatively connected to a center portion of the shaft for pivotal movement around a pivotal axis of the shaft, and the column inclination adjusting means include a clamping ring mounted adjustably in a circumferential direction on the shaft. Further, the clamping ring has a portion of inwardly reduced radial thickness, and a stop member projects from the base into said ring portion to restrict the pivotal movement of the column. By tightening the clamping ring around the shaft in a desired position, the column inclination is restricted to what is permitted by the relative movement of the stop member in the ring portion of inwardly reduced radial thickness.
Suitably, the ring portion permits a pivotal movement on the order of 90°.
To ensure that the drill stand settings do not change during coring, the bearing bracket preferably has a cap portion that can be tightened to lock the shaft against rotation.
Preferably, the shaft is tubular. A tubular shaft is more rigid than a solid shaft of the same weight and thereby contributes to increased stability.
Advantageously, one of the shaft and the bearing bracket has a first mark indicating the normal position of the column and the other has a scale indicating the actual inclination of the column. Further, one of the clamping ring and the bearing bracket has a second mark indicating the normal position of the column and the other has a scale indicating the actual inclination of the column at which the clamping ring restricts further inclination of the column. Thereby, the setting of a desired inclination of the column is facilitated.
Preferably, the center portion of the shaft has a laterally projecting generally cylindrical stud, to which the column is detachably connected, the generally cylindrical stud has a bottom portion attached to the shaft, an intermediate portion of reduced diameter and having a circumferential groove, and a top portion of still more reduced diameter, the column has a tubular main portion of square cross-section and a generally cylindrical, tubular bottom portion, said tubular bottom portion including a lower sleeve fitting around
the portion of reduced diameter of the stud, and an upper tubular plug fitting into a bottom portion of the square tube, and a stop member extends through the wall of the generally cylindrical, tubular bottom portion of the column and into the groove to lock the column at least axially to the shaft. By tightening the stop member against the bottom of the groove, the column may also be non-rotatably locked to the shaft. This design provides a stable mounting of the column to the shaft, and after rotating the column around its longitudinal axis, it can be locked at any desired orientation.
To facilitate the setting of a desired orientation of the column, it is also preferred that an indexing member is provided on the bottom portion of the stud, said indexing member having a portion projecting into the intermediate stud portion of reduced diameter, and that the sleeve has a plurality of recesses matching the projecting portion of the indexing member.
Advantageously, at least three of the recesses are spaced apart 90°. Thereby it will be easy to swiftly position the core drill straight ahead of or straight laterally of the column.
To provide for positioning of the core drill in other positions than straight ahead of or straight laterally of the column, it is suitable that the indexing member can be inactivated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be described in more detail with reference to preferred embodiments and the appended drawings.
Fig. 1 is a perspective view of a core drilling device having a drill stand in accordance with a preferred embodiment of the present invention.
Fig. 2 is a side view, partly in cross-section, of the drill stand of Fig. 1 having a base and a column pivotally attached to the base.
Fig. 3 is a front view of the drill stand of Fig. 2.
Fig. 4 is a top view of the drill stand of Fig. 2.
Fig. 5 is a perspective view of the base of Figs. 1 to 3 having a tubular shaft journalled in bearing brackets at its ends and having a laterally projecting stud for attachment of the column to the shaft.
Fig. 6 is a side view of the shaft end of the base of Fig. 5, with the stud shown in cross- section.
Fig. 7 is a longitudinal cross-sectional view of a column adapter having a generally cylindrical, tubular bottom, fitting around a portion of reduced diameter of the stud, and an intermediate portion fitting into a bottom portion of a square tube forming a main portion of the column.
Fig. 8 is a perspective view of the column with the adapter attached to the stud on the shaft, the shaft carrying a clamping ring and being mounted in the bearing brackets.
Fig. 9 is a cross-sectional view taken along line EX-IX in Fig. 3 showing the clamping ring having a portion of inwardly reduced radial thickness, and a stop member projecting from the base into said ring portion to restrict the pivotal movement of the column.
MODE(S) FOR CARRYING OUT THE INVENTION
The core drilling device shown in Fig. 1 has a core drill 1 and a drilling device 2 for rotating the core drill. The drilling device is carried by a drill stand 3, which has a base 4 adapted to be anchored to a floor, a wall, or fitted to a structure that in turn is anchored in a suitable manner, and a column 5 having a normal position at right angles to the base 4. At its lower end, the column is pivotally attached to the base 4 by a shaft 6, and means are provided for adjusting the inclination of the pivotable column 5 in relation to its normal position. The column has a gear rack 7 along which the drilling device 2 is movable toward and away from the base 4, either manually or by means of an automatic feeding device. The shown stand has a wheel assembly 8 mounted to a rear end of the base 4 to facilitate a translocation of the core drilling device. When the core drilling device is standing on a floor, the base 4 engages the floor, and the wheels of the assembly 8 carry no weight at all or no appreciable part of the weight of the core drilling device. Further, in the shown embodiment a pair of longitudinal supports 9 extends from positions close to the wheels and substantially parallel to the column 5, and the top of the column has a support member
that is slidingly connected to the supports 9 to assist in maintaining the column in a desired position.
Figs. 2, 3, and 4 are a side view, a front view and a top view, respectively, of the drill stand 3 of Fig. 1. The base 4 has a bifurcated bottom frame having two parallel side members 10, 11 and an interconnecting rear member 12. Preferably the side members are square tubes and the rear member is a rectangular tube. From the center of the rear member 12, two spaced parallel flat rods 13, 14 extend forward parallel to the side members up to a flat rod cross piece 15 parallel to the rear member and interconnecting the two side members. The slot formed between the two parallel flat rods 13, 14 is adapted to receive the shank of an expansion bolt, not shown, for adjustably anchoring the drill stand to the floor. To permit leveling of the base 4 in case the floor is uneven, the base has four leveling screws 16, one at each end of the two side members 10, 11. Each screw is mounted in a threaded insert 17 extending vertically through the square tube and is of sufficient length to abut against the floor and permit the leveling. Similarly, at the center of the rear member 12, there is a vertical threaded insert, not shown, for a screw 18 for attaching the wheel assembly 8 to the base 4.
In accordance with the present invention, the base 4 has a bearing bracket 20 at each end of the shaft 6, and each bearing bracket has a cap portion 21 that can be tightened by means of a screw 22 to lock the shaft against rotation. Each of the two bearing brackets is attached, preferably by welding, to a vertical side of the side member 10 or 11 that faces the other side member 11 or 10, and the ends of the cross piece 15 are welded to the bearing brackets, preferably at the rear end of the brackets. In each bearing bracket 20 there is a plain bearing bushing 23 for pivotal movement of the shaft 6, and each bushing has an axial split 24 along it to permit the tightening of the bearing bracket 20. The bearing bushing 23 is locked against axial displacement relative to the bearing bracket 20, e.g. by having at each side a radially outwards projecting flange, not shown, which flanges project over an inner portion of the sides of the bearing bracket 20. Both ends of the shaft 6 are provided with a circumferential series of axially extending grooves, not shown, and similar grooves, also not shown, are provided on a bearing bracket surface facing the associated bearing bushing 23. These grooves assist in locking the shaft 6 against rotation when the screws 22 are tightened.
The lower part of the bearing brackets 20 are preferably welded to the side member 10 or 11. As can be seen in Fig. 3 a lower part of the bearing brackets 20 extends slightly upwards, at an angle α, from the side member 10 or 11 in a direction towards the opposite side member 11 or 10, whereas the upper part of the bearing brackets 20 extends vertically. Thereby the upper part of the bearing brackets 20 becomes separated from the most adjacent leveling screws 16 by the distance dl, providing room for tools working on the screws 16. This arrangement also provides for a void at the front of the base 4, beneath the bearing brackets 20 and the shaft 6, which makes it easier to place the base 4 where small obstacles may protrude from the ground. The angle α is preferably at least 25°.
The column 5 has one end operatively connected to a center portion of the shaft 6 for pivotal movement around a pivotal axis of the shaft, and the column inclination adjusting means include a clamping ring 25 mounted adjustably in a circumferential direction on the shaft 6. On the shaft end where the clamping ring 25 is mounted, the circumferential series of axially extending grooves is extended to cover the shaft area clamped by the clamping ring. Further, as best shown in Fig. 9, the clamping ring 25 has a portion 26 of inwardly reduced radial thickness, and a stop member 27 projects from the base into said ring portion
26 to restrict the pivotal movement of the column 5. By clamping the clamping ring 25 around the shaft 6 in a desired position by tightening a clamping ring screw 28, the column inclination is restricted to what is permitted by the relative movement of the stop member
27 in the ring portion 26 of inwardly reduced radial thickness. Preferably, the ring portion 26 permits a pivotal movement on the order of 90°, but if desired, the permissible movement can be smaller or even larger. To restrict any undesirable axial displacement of the shaft in the bearing brackets, at one end of the shaft 6, the clamping ring 25 is mounted at a position axially inside of but close to one of the bearing brackets 20, and at the other end of the shaft 6, a suitable stop, such as a screw 29, for example, best shown in Fig. 3, is attached to the shaft at a position axially inside of but close to the other bearing bracket 20.
As illustrated in the drawings, the shaft 6 preferably is tubular. A tubular shaft is more rigid than a solid shaft of the same weight and thereby contributes to increased stability. On the shaft side that carries the clamping ring 25, the tubular shaft has an annular end surface 30 provided with a first mark 31, suitably located in a top position when the column 5 is exactly vertical. The associated cap portion 21 of the adjacent bearing bracket 20 has a vertical end surface 32, which advantageously is provided with a matching scale 33
indicating the actual inclination of the column 5. To facilitate the determination of the inclination of the column 5, also the opposite end face of the tubular shaft 6 and the associated end face of the other bearing bracket cap portion 21 are provided with a corresponding mark and a matching scale. Further, a second mark 34 indicating the normal, vertical position of the column is provided at the top of the cap portion 21 near the clamping ring 25. On its outer circumference, the clamping ring has a graduated scale 35 indicating the actual inclination of the column 5 at which the clamping ring 25 restricts further inclination of the column. When the column has been given a desired inclination, the two bearing brackets 20 and the bearing bushings 23 carried thereby are clamped tight around the ends of the shaft 6 by tightening the screws 22. The axial split 24 in the bushings 23 permits such clamping. Then, the clamping ring 25 is loosened, turned until the stop member 27 prevents further rotation of the clamping ring, and then tightened again. In this way, the actual value of the inclination of the column 5 is preserved until the next time that the clamping ring 25 is loosened. Thus, the clamping ring 25 facilitates the setting of a desired inclination of the column. If a certain inclination will be used at some time in the future, it is also possible to read the scale and make a note of the scale value. Of course it is possible, if desired, to let one or both of the marks change places with the respective scale, and also to locate the mark or scale on another portion of the bearing bracket than on the cap portion.
As is best shown in Figs. 5 and 6, the center portion of the shaft 6 has a laterally projecting generally cylindrical stud 36, which in the shown embodiment is tubular. The column 5 is detachably connected to this stud that has a bottom portion 37 attached to the horizontal, tubular portion of the shaft, an intermediate portion 38 of reduced diameter and having a circumferential groove 39, and a top portion 40 of still more reduced diameter.
As is best shown in Figs. 2, 3, and 8, the column 5 has a tubular main portion 41 of square cross-section and a generally cylindrical, tubular bottom portion 42. As is best shown in Fig. 4, the gear rack 7 has a channel-shaped cross-section and is welded to the square tube 41 along a corner thereof. Fig. 7 shows that he tubular bottom portion 42 includes a lower sleeve 43 adapted to fit around the stud portion 38 of reduced diameter, and an upper tubular plug 44 adapted to fit into a bottom portion of the square tube 41. The square tube 41 and the tubular bottom portion 42 are joined by welding, but of course other fixing means such as e.g. screws could be used. A stop member 45 extends through the wall of the
generally cylindrical, tubular bottom portion 42 of the column and into the groove 39 to lock the column 5 at least axially to the shaft 6. In the shown embodiment the stop member is a screw 45. When the screw is screwed out from the groove, the column can be lowered down onto the stud of the shaft or lifted up therefrom, and when the screw is loosely tightened by hand without the use of tools, the column 5 is axially fixed to the stud 36 and the shaft 6, but it can still be rotated around its longitudinal axis. If the screw 45 is tightened with a tool, the column 5 will become locked against rotation.
To facilitate the setting of a desired rotational orientation of the column 5, an indexing member 46 is provided on the bottom portion of the stud 36, said indexing member having a portion 47 projecting into the intermediate stud portion 38 of reduced diameter, and the sleeve 43 has a plurality of recesses 48 matching the projecting portion 47 of the indexing member 46. In the shown embodiment, the indexing member is a screw, and the projecting portion of the indexing member is the screw head 47, which is shaped like a control knob having a central projecting wing to offer a better grip for fingers. The number of recesses and their placement around the lower end of sleeve 43 may vary, but preferably at least three of the recesses 48 are spaced apart 90°. Thereby it is easy to position the core drill straight ahead of the drill stand and perpendicularly to the right or the left side thereof. If desired, the indexing screw 46 can be inactivated temporarily by unscrewing it until its head 47 is located radially outside the lower end of sleeve 43. Then, the column 5 can be rotated freely about its longitudinal axis to any desired angular orientation.