The present invention relates to a drill stand designed to be used with a drill motor and a core drill and to normally be fixedly fastened to a floor or wall using either an expander bolt or vacuum. In the latter case a vacuum cap and gasket is applied to the expander bolt aperture. The drill stand preferably has a back support clamped to its drill stand.
When core drilling in concrete, asphalt, brickwork or similar building materials, a drill stand is usually used. The drill stand is mounted via anchor bolt(s) or vacuum. Usually the drilling is done in a floor or a wall using a drill bit to prepare a hole with a diameter of usually 100-200 mm, and in extreme cases up to 600 mm. Often it is required to drill either a straight or an angled hole. Therefore a special kind of drill stand has a drill column that can be tilted, usually from zero degrees to forty-five degrees. The drill column is often fixed with a tiltable back support that is slidably connected to the drill column and is locked to the column in a suitable position by a clamping arrangement.
Husqvarna DS 160 C is a drill stand of this type. It has a clamping mechanism comprising a screw to be tightened on the rear side of its drill column; i.e., from the back side of the drill stand. This is somewhat awkward as all other important settings of the drill stand are managed from the side of the drill stand.
An object of the invention is to provide a drill stand having an improved clamping mechanism and a more reliable system for vacuum locking.
At least one of the above mentioned objects and/or problems are met by providing a drill stand in accordance with the invention having the characteristics appearing from the appended claims. The drill stand, according to the invention, is thus essentially characterised in that the clamping arrangement comprises a center clamp having a flange part fitting in the elongate opening and having protrusions, right and left, from the flange part intended to contact the inside forward surfaces, right and left, when clamping. The clamping arrangement further comprises an outer clamp right and an outer clamp left, each having at least a lateral contact surface arranged to contact the respective outside rear surface when clamping, each outer clamp being arranged outside of the center clamp and having outer angled contact elements intended to cooperate with center angled contact elements to provide a longitudinal backwards motion of the center clamp in relation to the outer clamps when a clamping element is pressing the outer clamps laterally together against the center clamp making its protrusions press against the inside forward surfaces, and making the lateral contact surfaces of the outer clamps press against the outside rear surfaces; i.e., providing clamping in a longitudinal direction. In this way a clamping in the longitudinal direction can be achieved from the side of the drill stand. This is a distinct advantage compared to the prior art drill stand mentioned above.
In a further improved embodiment, the outer clamps, right and left, each have a longitudinal contact surface, right and left, contacting a longitudinal contact surface of the track or drill column, right and left when clamping therefore creating a clamping also involving clamping in a lateral direction in addition to the clamping in the longitudinal direction. This provides an especially good clamping where six contact surfaces of the track are involved. A further improvement is a more reliable vacuum mounting where a slot guard (32) is provided around the expander bolt aperture(s). The slot guard is preferably made of steel and is more scratch resistant than the base plate, which is usually made of aluminium. Thereby, the slot guard provides a more reliable seal for the vacuum locking than the prior art solutions. This is because the top surface of the slot guard is provided with a gasket for sealing between the slot guard and a vacuum cap. Further features and advantages are presented in the description of preferred embodiments with the help of the drawing figures.
The invention will be described in the following in closer detail by means of various embodiments thereof with reference to the accompanying drawings wherein like numeral references have been used in the various drawing figures to denote corresponding components.
The base plate 2 is provided with an expander bolt aperture 31, extending in a longitudinal direction and used for fastening the base plate 2 in a floor or in a wall. The aperture 31 is arranged such that an anchor bolt is anchored to the floor or wall and can extend from the floor or wall and up through the aperture 31. The base plate 2 can be fastened to the floor by means of a nut, which is screwed on to the protruding part of the anchor bolt and tightened against the base plate 2. Alternatively, a vacuum lock can be used. A slot guard 32 is provided around the expander bolt aperture and sealingly applied to the base plate 2. The slot guard 32 is made of steel and is more scratch resistant than the base plate 2, which is usually made of aluminium. Thereby the slot guard 32 provides a more reliable seal for the vacuum locking than the prior art solutions. This is because the top surface of the slot guard is provided with a gasket 33 for sealing between the slot guard and a vacuum cap 34 when using vacuum locking (see
Each of the outer clamps 17, 17′ has a lateral contact surface 18, 18′, arranged to contact the respective outside rear surface 13, 13′ of the track 10. Each outer clamp 17, 17′ is arranged outside of the center clamp 15 and has an outer angled contact element 19, 19′, intended to cooperate with center angled contact elements 20, 20′ arranged on the center clamp 15. Preferably, the outer angled contact elements 19, 19′ and the center angled contact elements 20, 20′ are provided in the form of angled surfaces, i.e. surfaces that neither run in a longitudinal nor in a lateral direction, but in an intermediate direction. However, it should be noted that in alternative embodiments either the center angled contact elements 20, 20′or the outer angled contact elements 19, 19′ could be provided in the form of something else than angled surfaces. For example, one or both of the center angled contact elements 20, 20′ could be provided as having a contact area in the form of a bump of various shape. Also the contact area could be part of a rotatable body like a roller; e.g., using ball or roller bearings to reduce friction. And of course all this could also apply to one or both of the contact areas of the outer angled contact elements 19, 19′. Preferably, the outside rear surfaces 13, 13′ as well as the inside forward surfaces 14, 14′ of the track 10 run in an essentially lateral direction.
The center clamp 15 has protrusions, right 16 and left 16′, extending laterally from the flange part 26 and intended to contact the inside forward surfaces 14, 14′ of the track 10. The outer clamps, right and left 17, 17′ have longitudinal contact surfaces, right and left 22, 22′ contacting a longitudinal outside contact surface, right and left 23, 23′ of the track 10 or drill column 4.
When the clamping element 24, 25 presses the outer clamps 17, 17′ together in a lateral direction against the center clamp 15, the outer angled contact elements 19, 19′ of the outer clamps cooperate with center angled contact elements 20, 20′, providing a longitudinal backwards motion of the center clamp 15 in relation to the outer clamps 17, 17′. Thereby, the protrusions 16, 16′ of the center clamp 15 are pressed against the inside forward surfaces 14, 14′ and the lateral contact surfaces 18, 18′ of the outer clamps are pressed against the outside rear surfaces 13, 13′. This way a clamping in a longitudinal direction is provided. If the outer clamps 17, 17′ are also provided with longitudinal contact surfaces 22, 22′, a clamping also in the lateral direction is possible. This provides a further improved embodiment having clamping in both a longitudinal and a lateral direction. Therefore, when the outer clamps 17, 17′ are pressed together, the longitudinal contact surfaces 22, 22′ of the outer clamps are pressed against the outside contact surfaces 23, 23′ of the track 10 or the drill column 4, providing a clamping in a lateral direction.
Preferably, the clamping element 24, 25 comprises a clamping screw 24 and a lock nut 25. The clamping screw 24 is adapted to be fastened to the back support 7 and to run through holes 36, 36′ in the outer clamps 17, 17′ and through a hole 37 in the center clamp 15. The lock nut 25 is arranged to press against either of the outer clamps 17, 17′, i.e. the nut could be located either on the right or left side of the drill stand.
The clamping screw 24 can be fastened to the back support 7 by being led through a clamping screw hole 38 in a first tongue 39 of a clamping fork 40 and further on through a lock nut aperture 42 in a second tongue 41 of the fork, and being secured in a lock nut 25. The lock nut aperture 42 is adapted to prevent the nut 25 from rotating but also to enable it to at least partly move through the aperture 42 and press against either of the outer clamps 17, 17′.
The clamping element 24, 25 could also be a tensioning device with a rod having a head in one end and quick tensioner in the other, like a cam rotatable around an axis lateral to the length axis of the rod and the cam supplied with a handle for quick tensioning without tools.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2007/083507 | 11/2/2007 | WO | 00 | 4/30/2010 |