The invention pertains to a device and a method for fastening a first object on a second object, as well as to a device for generating percussions.
Fastening devices frequently comprise a sleeve and an arbor, wherein the sleeve features a first load application means for the first object and a passage. The sleeve is inserted into a drilled hole in the second object. The arbor can be inserted into the passage in order to expand the sleeve in the drilled hole and to thusly achieve a fastening effect. However, a minimum insertion depth of the sleeve into the drilled hole and therefore a minimum depth of the drilled hole need to be ensured in order to achieve satisfactory holding forces.
If the objects are painted or provided with a protective layer, in particular, there also is a risk of damaging the paint or the protective layer.
The invention is based on the objective of making available a device for reliably fastening a first object on a second object. The invention also aims to make available a method for reliably fastening a first object on a second object. The invention furthermore aims to make available a device for carrying out such a method.
The objective of the invention is attained with a device for fastening a first object on a second object which features a sleeve and an arbor, wherein the sleeve features a first load application means for the first object and an abutment for an outer surface of the second object, as well as a passage, wherein the passage features an insertion section that lies adjacent to the first load application means and an expansion section, wherein the expansion section features a contraction that is smaller than the outside dimensions of the arbor, and wherein the contraction extends at least up to the point of the passage that is the closest adjacent point to the abutment.
One preferred embodiment is characterized in that the contraction increasingly contracts the passage from the point of the passage that is the closest adjacent point to the abutment to the second load application means. It is particularly preferred that the contraction features a conical and/or cylindrical section.
One preferred embodiment is characterized in that the arbor can be inserted into the insertion section in a freely movable fashion.
One preferred embodiment is characterized in that the sleeve features a second load application means for the second object adjacent to the expansion section.
One preferred embodiment is characterized in that the device features a sealing element for realizing a seal between the sleeve and the second object. It is particularly preferred that the sealing element is realized in the form of an O-ring or a molded plastic part.
One preferred embodiment is characterized in that the first load application means features a holding element that, in particular, is positively and/or integrally fixed on the sleeve. It is particularly preferred that the holding element is arranged such that it is freely rotatable relative to the sleeve about an axis and realized such that it has an asymmetric cross section perpendicular to said axis.
The objective of the invention is also attained with a method for fastening a first object on a second object, in which a) the second object is provided with a recess, b) a sleeve with a first load application means for the first object, with an abutment for an outer surface of the second object, and with a passage is inserted into the recess, wherein the passage features an insertion section that lies adjacent to the first load application means and an expansion section, c) an arbor is inserted into the insertion section, wherein the expansion section features a contraction that is smaller than the outside dimensions of the arbor, and d) the arbor is driven into the expansion section such that the region of the sleeve inserted into the recess is expanded against the recess. Step d) is carried out, in particular, with the same tool that was used previously for carrying out step a).
The objective of the invention is also attained with a device for generating percussions on a fastening element which features a supporting means for supporting the device on a housing of a drill in a rotationally rigid fashion, a power take-off means for tapping a rotational movement of a rotatively driven drill chuck of the drill, a striking element for transmitting percussions to the fastening element and a striking mechanism for converting a rotational movement of the power take-off means into a linear movement of the striking element. The device preferably features a receptacle for the fastening element.
One preferred embodiment is characterized in that the device features, in particular, a step-down gear that is connected to the power take-off means on the input side and to the striking mechanism on the output side.
One preferred embodiment is characterized in that the striking mechanism features a force detecting means for detecting a contact force of the fastening element on a surface, as well as coupling means that disengage the power transmission from the power take-off means to the striking element as long as the contact force of the fastening element on the surface is lower than a predetermined force and engage the power transmission from the power take-off means to the striking element when the contact force of the fastening element on the surface is at least as high as the predetermined force.
Embodiments of the invention are described in greater detail below with reference to the drawings. In these drawings:
According to a method for fastening the not-shown first object on the second object 110, the second object 110 is initially provided with the drilled hole 112. The sleeve 120 is then inserted into the drilled hole 112. The arbor 130 is subsequently driven into the insertion section 151 (
a shows a detail of a sleeve 220 of a fastening device 200, in which the contraction 260 extends beyond the point of the passage 250 that is the closest adjacent point to the abutment 240. Consequently, the entire drilled hole in the second object, particularly also the wall of the drilled hole near the surface, is used for producing a press fit. The sleeve 220 furthermore features a second load application means 280 for the second object adjacent to the expansion section. The load application means 280 features grooves 281 and preferably circumferential and, in particular, flattened projections 282 in order to achieve an improved clamping effect and/or positive fastening of the sleeve 220 in the drilled hole. The contraction 260 increasingly contracts the passage 250 from the point of the passage 250 that is the closest adjacent point to the abutment 240 to the second load application means 280 and features a cylindrical section 261. An arbor 230 is illustrated in its end position so that it is clear that the inside dimensions of the contraction 260 are smaller than the outside dimensions of the arbor 230.
b shows a detail of a sleeve 225 of a fastening device 205, in which the contraction 265 extends beyond the point of the passage 255 that is the closest adjacent point to the abutment 245. The sleeve 225 furthermore features a second load application means 285 for the second object adjacent to the expansion section. The contraction 265 increasingly contracts the passage 255 from the point of the passage 255 that is the closest adjacent point to the abutment 245 to the second load application means 285 and features a conical section 262. An arbor 235 is illustrated in its end position so that it is clear that the inside dimensions of the contraction 265 are smaller than the outside dimensions of the arbor 235.
The fastening element 600 is initially anchored in the surface. A rail 691 with a longitudinal slot is then aligned with the hold-down implements 693, 694 and threaded into the fastening element 600. The holding element 690 is turned by approximately 90° with an auxiliary tool 695 such as, for example, an open-end wrench or socket wrench such that the rail 691 is positively fastened on the surface with the aid of the hold-down implements 693, 694. In order to prevent the hold-down implements 693, 694 from turning back, it is particularly preferred to provide a catch between the fastening element 600 and the rail 691. The catch features, for example, a tab on the fastening element and a groove in the rail.
The percussion device 1100 makes it possible to use a single drill 1104 for drilling a hole and for driving the arbor into the sleeve. For this purpose, the drill 1104 that preferably consists of a battery-operated electric drill or screwdriver without percussion function is initially fitted with a stop bit and a drilled hole is produced in a surface. Subsequently, the percussion device 1100 is installed on the drill 1104 over the stop bit and an inventive fastening element is inserted into the receptacle 1150 and then anchored in the surface by means of the striking element 1130 that drives the arbor 1135 into the sleeve of the fastening element 1134. In this case, the impact energy is not necessarily so high that the arbor can be driven in with a single strike. On the contrary, it is preferred to drive in the arbor with several strikes that are successively carried out within short time intervals. The desired striking frequency and impact energy is defined with the aid of the step-down gear.
The dimensions of the striking mechanism and of the fastening elements are preferably adapted to one another in such a way that the striking element cannot strike the sleeve, but rather stops a short distance before reaching the sleeve such that the arbor is always driven in to a desired depth without subjecting the sleeve to mechanical stress or damage.
In fastening devices with sealing elements, it is preferred to press the sleeve against the surface with a predetermined force while the arbor is driven in. This is preferably achieved in that the striking mechanism features a force detecting means for detecting a contact force of the fastening element on a surface, as well as coupling means that disengage the power transmission from the power take-off means to the striking element as long as the contact force of the fastening element on the surface is lower than a predetermined force and engage the power transmission from the power take-off means to the striking element when the contact force of the fastening element on the surface is at least as high as the predetermined force. Consequently, the striking movement is only carried out once the contact force reaches the predetermined force. The predetermined force is preferably a force at which the sealing element develops its sealing effect.
In not-shown embodiments, a percussion drill, in which the rotary function is switched off, or a setting device operated with gas, powder, compressed air or batteries is used for driving in the arbor.
The invention was described with reference to examples of a device for fastening a first object on a second object and a corresponding fastening method. In this case, the characteristics of the described embodiments also can be arbitrarily combined with one another within a single fastening device or a single fastening method. It should furthermore be noted that the inventive devices and the inventive method are also suitable for other purposes.
Number | Date | Country | Kind |
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10 2010 003 130.5 | Mar 2010 | DE | national |