The invention pertains to a device for suspending a rail, especially a travel rail of an overhead conveyor or a hoisting machine, from a traversing gear or supporting structure with a tension element, being secured by one end to the rail, while a bolt passes through the tension element and is received by a fixing device that is secured to the rail.
Thus, from the prospectus (March 2000 edition) entitled “Crane Construction Kit KBK classic and KBK ergo” of the firm Demag Cranes & Components GmbH, Wetter, Germany, there is known a crane construction kit system with c-shaped and I-shaped rails which are open at the bottom, by which one can implement different kinds of constructions, such as monorail telphers, single and double-beam overhead cranes. In each case, the rails are suspended from support structures, other rails, or traversing gears which run into other rails. These suspension systems have a pendulum type design, which ensures that the rails align themselves and thus come into a state of equilibrium, i.e., no significant bending load occurs in the tension element. The pendulum suspension occurs through ball and socket bearings, having steel ball segments and mating ball cups with plastic slide shells. The ball segments are fastened to the end of a compound tension element. Thus, the tension element for the most part consists (looking down from above) of a lug to fasten the tension element to the supporting structures, other rails or traversing gears, and a shaft joined to it as a single piece, on which the ball segment is screwed and secured.
In a suspension system of c-shaped rails open at the bottom, with a web broadening out toward the top and arranged at the top side of the rail, preferably a y-shaped or T-shaped web, the fixing device consists of two identical fixing parts. These fixing parts are formed as sheet metal parts in such a way that, after being fitted together and held by screws, the broadening web of the rail is clamped in the lower region and the ball cup is accommodated in the upper region, while the tension element is passed through an opening.
This type of suspension system has been popular for many years and is easily installed on any given portion of a rail, since the fixing parts are fitted together there and tightened together by the screws for a clamping against the rail.
From US 2004/0238473 A1 there is known a crane arrangement in which a bridge girder can run on parallel rails which are spaced apart from each other by means of traversing gears arranged at its ends. The bridge girder is clamped together with the traversing gears by u-shaped stirrups, open at the bottom, which enclose the bridge girder. Between the stirrups and the traversing gears there are vertically oriented ball and socket bearings, so that the traversing gears can turn 360 degrees about a vertical axis relative to the bridge girder and can also be tilted laterally. The ball and socket bearings used have balls made of steel and cups of nylon.
In these ball and socket elements, the ball of the tension element must be introduced into the ball cup, while the shaft passes through the central bore of the cup. Therefore, the tension elements are made of at least two parts, namely, a tension rod and a ball head, which are fastened to each other after being assembled with the tension rod introduced through the central bore in the ball cup. One often uses ball nuts that are screwed onto the tension rod. This connection is secured, for example, by a cotter pin.
The ball cups can be ruined by improper use or deficient maintenance. This results in increased friction between ball head and ball cup. In the case of two-part tension elements made from tension rod and ball head, the element securing the connection between tension rod and ball head is then overloaded. This can result in collapse of the bridge girder. The securing element can also fail, which likewise results in a failure of the suspension. Furthermore, the tension rod is weakened by the notch effect of the thread placed on it. Moreover, when the load is removed from the rail, the rail lifts slightly and the ball cup is pulled off from the ball head. When the rail is then placed under load, there is an abrupt loading of the ball and socket joint. This also has to be factored into the design.
Moreover, suspension systems are known from the firm Ingersoll Rand Zimmerman, Milwaukee, USA (see, for example, www.irtools.com/_imgLibrary/complete/Zimmerman HaengerAjc—1.jpg) for a c-shaped crane rail open at the bottom, having a y-shaped web broadening at the top and arranged on the top side of the rail for a fixing unit made of two identical fixing parts. This suspension system has a tension element consisting essentially of a tension rod and a lug fastened thereto. The tension rod here is mounted in the lug by its lower end, able to turn about a vertical axis, and secured rigidly to a supporting structure at its upper end. The lug, in turn, is fastened by its bore to a bolt, extending in the lengthwise direction of the rail. Thus, the tension element can swivel transversely to the rail and can turn about a vertical axis. The tension element is rigid in and against the lengthwise direction of the rail. Furthermore, the bolt for the lug is mounted in the fixing parts. The fixing parts can swivel about the bolt and restrain a y-shaped web by means of screws. The screws for this are led through a borehole in the web.
Also known from the firm Krantechnik Müller, Lebach, Germany, are additional suspension systems for the above-described c-shaped crane rails, open at the bottom, with the y-shaped broadening web. These consist essentially of a two-piece tension element, two pivoting bearings, a bolt, a bracket and a fixing device. The tension element consists of an upper and lower piece, which are screwed together. The tension element has one borehole each at its upper and its lower end, each of which receive a pivoting bearing with a ball cup and a ball head. The lower ball head is connected to the bolt, which extends in the lengthwise direction of the rail. The ends of the bolt extending in front of and behind the ball head are each secured in pivoting manner and by cotter pin in the legs of a u-shaped bracket, open at the top, whose web extending below and at a distance from the bolt is accommodated by the fixing device with the y-shaped web. For this, the fixing device in turn consists of two identical fixing parts, which are fastened by screws to clamp against the web of the bracket and the y-shaped web of the rail. The tension element again consists of multiple pieces.
The problem of the invention is to provide a device for suspending a rail, especially a travel rail of an overhead conveyor or hoisting machine, which device is secure and exhibits a simple construction method.
The problem is solved by the device indicated in claim 1. Advantageous embodiments of the device are given in the subsidiary claims 2 to 11.
According to the invention, in a device for suspending a rail, especially a travel rail of an overhead conveyor or a hoisting machine, from a traversing gear or supporting structure with a tension element, being secured by one end to the rail, while a bolt passes through the tension element and is received by a fixing device that is secured to the rail, one achieves a secure construction as well as a long service life and a low structural height in that the tension element is one piece and exhibits a lower borehole for the bolt as well as an upper borehole in order to fasten it to the traversing gear or supporting structure. The one-piece tension element directly increases safety, as there are no joints within the tension element that may fail. Furthermore the tension element can be produced in an especially simple manner. Placing two boreholes in the tension element most easily provides mounting points for the tension element.
An especially simple and secure construction of the tension element is achieved in that the tension element is a flat connection rod-like bracket.
The simple construction method is also achieved in conjunction with angular mobility of the suspension in that the bolt is fastened to the tension element by means of a ball-shaped joint, especially a pivoting bearing. In this way, the bolt can be directly connected to the fixing device and the structural height of the overall suspension is minimized. This direct connection increases the safety of the suspension. The use of a pivoting bearing makes it possible to achieve long service life. The design is simplified, in that customary, industrially manufactured pivoting bearings can be used, which are relatively low in wear and tear.
By a pivoting bearing is meant commercially available, ready to use, standardized and industrially manufactured radial pivoting bearings such as those per DIN ISO 12240, which are jointed and enable three-dimensional adjustments. Pivoting bearings are structural units that have an outer race, in which an inner race is mounted. The inner race has a cylindrical bore to accommodate a bolt without twisting, and a spherical outer slide track to form the ball head. This outer slide track engages with a hollow spherical inner slide track of the outer race, which is inserted by its cylindrical envelope surface in a bore without twisting. Both the outer slide track and the inner slide track can be made of steel and stand directly against each other. In this case, a supply of lubricant is most often provided for. In the present application, one uses pivoting bearings that have a slide layer or a slide ring, such as one of plastic or Teflon, between the inner and outer race. This slide ring is then secured to the outer race and the inner race slides in the slide ring. In another design, the outer race as a separate part can be omitted and its function is talken over by the tension element. The inner race in this case is inserted transversely into the broadened bore in the tension element and turned through 90 degrees in the bore to take up its working position. After this, the broad portion of the bore and the gap between inner race and bore is filled with a plastic, which hardens to form the slide ring.
The structural height is further minimized in that the bolt and the tension element are at least partly recessed into the fixing device, looking in the suspension direction. Preferably, the entire bolt is completely recessed into the fixing device, looking in the suspension direction. This also facilitates a secure fastening of the bolt in the fixing device.
In order to achieve a recessing of the tension element and the pivoting bearing in the fixing device, the fixing device has an intermediate space, looking at right angles to the direction of suspension and looking at right angles to the bolt, so that the fixing device has a u-shaped form open at the top, and the tension element or the tension element and the bolt protrude into the intermediate space. In a preferred embodiment, the bolt is oriented with its lengthwise dimension parallel to the lengthwise direction of the rail.
A secure connection of the bolt in the fixing device and thus a direct flow of force is achieved in that the bolt is held free of torsion in bores in the fixing device by its ends protruding at either side beyond the pivoting bearing. In this way, only the pivoting bearing is under stress due to the movements of the suspension system.
In one embodiment, the fixing device has two fixing parts, between which the bolt with its ends and the rail being supported are clamped by means of screws.
An embodiment especially safe from collapse is achieved in that the fixing device is a one-piece design. This embodiment provides advantageously that the fixing device is held in the fixing position by means of fasteners designed as screws and that in the fixing position, when seen in lengthwise direction of the rail, the slightly pre-tightened screws rest against the sides of the support element. This can easily be achieved with grub screws.
A preferred embodiment provides that a ball-shaped joint, especially a pivoting bearing, is located in the upper borehole of the tension element.
In an alternative embodiment, the fixing device has a frame-like fixing part, which can be fastened in a T-shaped groove of the rail being supported.
Additional features, details, and benefits of the invention will emerge from the subsidiary claims and the following description of sample embodiments by means of the drawing. This shows:
In
These suspensions 1 have pivoting bearings and thus have a pendulum type design, which ensures that the rail 2 and the travel rails 3 automatically orient themselves and thus come into a state of equilibrium, i.e., there is no significant bending load in the suspension 1, or in particular in the tension element 6 arranged in the suspension (see
Thus, it is possible to grab the hoisting machine at the load or a suspended switch and move it along the rail 2 and the travel rail 3 without a special drive unit for this. When moving along the travel rail 3, it often happens, due to the flow of force off center—and depending on the particular position of the hoisting machine on the rail 2—that the rail 2 with the hoisting machine will become slanted relative to a position perpendicular to the travel rails 3. This slanted position is around 20 to 30 degrees. Normally, such a slanting would result in a seizing of the rail 2 or the traversing gears 4 on the travel rail 3. But since, as previously mentioned, the suspensions 1 are of a pendulum kind, when the travel rails 3 become crooked, they can simply reduce their mutual spacing and the traversing gears 4 can continue to travel unhindered in the travel rails 3. By pendulum suspension 1 is meant here that they enable a turning about a vertical axis and also a lateral tilting.
As an alternative, a pivoting bearing 8 can also be arranged in the upper bore 10.
In the event that the inner race 8a and the outer race 8b are made of steel and are in direct contact, a supply of lubricant is also usually provided. In a different design, the outer ring 8b can be omitted as a separate part and its function is taken over by the tension element 6. The inner race 8a is introduced transversely into the widened bore 11 in the tension element 6 and turned through 90 degrees in the bore 11 into its working position. After this, the widening of the bore 11 and the gap between inner race 8a and bore 11 is filled with a plastic, which hardens to form the slide ring.
The fixing parts 9a, 9b with limited angular mobility around the bolt 7 form a kind of pincer mechanism to restrain the rail 2. However, the special feature of the fixing parts 9a, 9b is that their angular mobility is limited such that, even in the open position, the ends 2b of the web 2a cannot slip down from the lengthwise opening 12 of the fixing device 9 and are thus firmly restrained.
The fixing device 9 of the suspension 1 in the first embodiment, especially its fixing parts 9a and 9b, has an intermediate space 16 open at the top, running transversely and horizontally when viewed in the lengthwise direction of the rail 2, being bounded by a u-shaped fixing device 9, especially its web-like suspension regions 9c. On the inner sides 9e of the suspension regions 9c of the fixing device 9, which face each other, there are arranged flat conical projections 9f. The bores 13 of the suspension regions 9c of the fixing device 9 for the bolt 7 are continued centrally in these projections 9f. Thanks to the projections 9f, the intermediate space 16 is narrowed and resting surfaces are created for the pivoting bearing 8.
Moreover, this intermediate space 16 divides the pivoting connection of the two fixing parts 9a, 9b into a first and a second hinge-like pivot region. Each of these pivot regions has an arm 9g of the fixing region 9d of the particular fixing part 9a, 9b. Each of the arms 9g receives a portion of the bore 13 for the bolt 7, looking roughly down the center in the lengthwise direction of the rail 2. The arrangement of the arms 9g, the bolt 7 and the bore 13 is comparable to a multiple-section bolt connection.
In order to accomplish the aforementioned limiting of the angular mobility of the fixing parts 9a and 9b, bearing surfaces 17 are formed on the one fixing part 9a and mating surfaces 18 on the other fixing part 9b. The mating surfaces 18 are arranged on the lower sides of the free ends of the arms 9g and are basically oriented horizontally. The bearing surfaces 17 are situated at the side next to the beginning of the arm 9g on the fixing part 9a, 9b, which is opposite the free end, and thus they lie opposite each other in relation to the bolt 7.
In the open position of the fixing parts 9a and 9b, the bearing surfaces 17 and mating surfaces 18, which are arranged like the clamping jaws of pliers in relation to each other, come to bear against each other. In the fixing position, the bearing surfaces 17 are separated from the mating surfaces 18 by a gap 19. However, the bearing surfaces 17 and the mating surfaces 18 do not prevent a closing movement, i.e., a bearing in the manner of a pliers against the webs 2a between the gripping levers of a pair.
In order to be able to secure the fixing device 9 at a desired position in the lengthwise direction after it is shoved onto the web 2a or put together around the web 2a, there are two screws 14 provided. The screws 14 pass through the fixing parts 9a, 9b at such a height that they do not interfere with the web 2a and they cross through the opening region 12b of the lengthwise opening 12 beneath the arms 9g. By means of the screws 14, the fixing parts 9a, 9b can be moved about the bolt 7 and swiveled from the open position to the fixing position against each other, until the ends of the gripping arm regions 9d come to bear against the web 2a. It should be stressed once more that this clamping serves mainly to secure the fixing device 9 in the lengthwise direction of the rail 2 and has basically no fixing or supporting function.
Accordingly, the size, especially the height of the opening region 12b of the lengthwise opening 12, is chosen so that the screws 14 have sufficient room to cross the lengthwise opening 12 beneath the bolt 7 and above the web 2a. However, the height of the lengthwise opening 12 is not enough to shove the fixing device 9 in the assembled condition from one end of the rail 2 onto its web 2a in the lengthwise direction of the rail 2, which runs essentially horizontally. Such a movement is prevented because cylindrical connection sleeves 2c are arranged on the web 2a in the upper opening of the web 2a at the start and end of the rail 2. These connection sleeves 2c serve to join the ends of two rails 2 in butt fashion. Additional connection sleeves 2c are located at the c-shaped lower ends of the rail 2 (see
Thus, the fixing device 9 must be put together at the desired suspension point on the rail 2. For this, the two fixing parts 9a, 9b are joined together without the bolt 7 and the screws 14 at the desired suspension point on the rail 2 so that the bores 13 are aligned and the web 2a of the rail 2 is grasped by the fixing regions 9d of the fixing device 9. Then the bolt 7 is inserted in the lengthwise direction of the rail 2 into the bore 13 from one side, so that it passes through the part of the bore 13 of the first two arms 9g of the fixing parts 9a, 9b. Now, the tension element 6 with its pivoting bearing 8 is inserted into the intermediate space 16 and lined up with the bore 13. The bolt 7 is shoved further through the pivoting bearing 8 and the remainder of the bore 13 into the two second arms 9g of the fixing parts 9a, 9b until the head 7c of the bolt 7 comes to rest against the fixing device 9. At the other side, the other end 7a of the bolt 7 sticks out from the bore 13. To secure the bolt 7 in the bore 13, a circumferential groove 7d is provided at the end 7a of the bolt 7 sticking out, into which a snap ring 20 is inserted from the side, coming to bear against the other end of the fixing device 9.
Since the travel rails 3 have a cross section identical to the rail 2, one also finds there the above-described web 3a and the three connection sleeves 3c at the ends of the travel rails 3 (see
In an alternative embodiment of the fixing device 9, not drawn, the height of the opening region 12b and the size of the gap region 12a of the lengthwise opening 12 in the open position or the spacing of the arm-like fixing regions 9d of the fixing device 9 are chosen such that the fixing device 9 can be shoved onto the web 2a of the rail 2 from one end in the lengthwise direction of the rail 2, which runs essentially horizontally. The lengthwise opening 12, especially its opening region 12b, starting from the gap region 12a, is then provided with a sufficient height to allow the web 2a as well as the connection sleeves 2c to pass.
The size of the lengthwise opening 12 or the spacing between the arm-like fixing regions 9d of the fixing device 9 is chosen such that the fixing device 9 runs essentially horizontally in the lengthwise direction of the rail 2 and can be shoved onto the web 2a of the rail 2 from one end. The design of the fixing device 9 with the fixing regions 9d enclosing the web 2a in c-shaped manner ensures that the web 2a of a horizontally oriented rail 2, looking in the vertical direction, cannot slip downward from the fixing device 9 and thus the rail 2 is held firmly. Furthermore, the size of the lengthwise opening 12, especially its opening region 12b, starting from the gap region 12a, has sufficient height to allow both the web 2a and the cylindrical connection sleeves 2c, arranged in the upper opening of the web 2a at the start and end of the rail 2, to pass.
In order to secure the fixing device 9 in a desired position after shoving it onto the web 2a in the lengthwise direction of the rail 2, there are four screws 14. The screws 14 are configured as grub screws, being screwed into bores 15, configured as threaded bores, running essentially horizontally and transversely to the lengthwise direction of the rail 2, and bearing with their tip against or being lightly screwed into the narrow segment of the web 2a, i.e., the region of the gap region 12a of the lengthwise opening 12. It should be stressed yet again that these screws 14 basically serve only to secure the fixing device 9 in the lengthwise direction of the rail 2 and do not take on any support function.
The fixing device 9 of the first alternative suspension 1 also has an intermediate space 16 open at the top, looking transversely and horizontally to the lengthwise direction of the rail, being bounded by a u-shaped fixing device 9, especially its web-like suspension regions 9c. On the inner sides 9e of the suspension regions 9c of the fixing device 9, which face each other, there are arranged flat conical projections 9f. The bores 13 of the suspension regions 9c of the fixing device 9 for the bolt 7 are continued centrally in these projections 9f. Thanks to the projections 9f, the intermediate space 16 is narrowed and resting surfaces are created for the pivoting bearing 8.
In regard to the configuration of the pivoting bearing 8, refer to the description for
The height of the opening region 12b of the lengthwise opening 12 is chosen so that the screws 14 have sufficient room to cross the lengthwise opening 12 beneath the bolt 7 and above the web 2a. However, the height of the lengthwise opening 12 is not enough to shove the fixing device 9 in the assembled condition from one end of the rail 2 onto its web 2a in the lengthwise direction of the rail 2, which runs essentially horizontally. Such a movement is prevented because cylindrical connection sleeves 2c are arranged on the web 2a in the upper opening of the web 2a at the start and end of the rail 2. These connection sleeves 2c serve to join the ends of two rails 2 in abutting fashion. Additional connection sleeves 2c are located at the c-shaped lower ends of the rail 2 (see
Thus, the fixing device 9 must be put together at the desired suspension point on the rail 2. For this, the two fixing parts 9a, 9b are joined together at the desired suspension point on the rail 2 so that the bores 13, which are configured here as blind holes, enclose the bolt 7 and the web 2a of the rail 2 is grasped by the fixing regions 9d of the fixing device 9. The fixing parts 9a, 9b are then joined together by the screws 14. Thanks to the screws 14, the bolt 7 is held clamped and without twisting in the bores 13 of the fixing parts 9a, 9b. The screws 14 also press the fixing regions 9d of the fixing parts 9a, 9b sideways against the web 2a of the rail 2, so that the fixing device 9 is secured in a desired spot in the lengthwise direction of the rail 2.
The fixing device 9 of the second alternative suspension 1 also has an intermediate space 16 open at the top, looking transversely and horizontally to the lengthwise direction of the rail, being bounded by a u-shaped fixing device 9, especially its web-like suspension regions 9c. On the inner sides 9e of the suspension regions 9c of the fixing device 9, which face each other, there are arranged flat conical projections 9f. The bores 13 of the suspension regions 9c of the fixing device 9 for the bolt 7 are continued centrally in these projections 9f. Thanks to the projections 9f, the intermediate space 16 is narrowed and resting surfaces are created for the pivoting bearing 8, especially its inner ring 8a.
In regard to the configuration of the pivoting bearing 8, refer to the description for
This rail 2, instead of having the ends 2b of the y-shaped web 2a moving away from each other, has a T-shaped groove 2d at the upper side of the rail 2, narrowing toward the fixing device 9. Accordingly, this fixing device 9 is adapted to this type of rail 2. The fixing device 9 consists of a frame-like fixing part 9a, which is shoved into the T-shaped groove 2d from one end or, alternatively, when so configured as in the manner of a tenon block, it is inserted from above into the T-shaped groove 2d and then turned through 90 degrees, so that the fixing part 9a engages in part beneath the upper webs 2a of the groove 2d. In order to secure the fixing part 9a at a desired spot in the lengthwise direction of the rail 2, the fixing part 9a is pulled upward by screws 14 and thus thrusts against the bottom of the web 2a of the T-shaped groove 2d. The screws 14 thrust against the top of the web 2a of the T-shaped groove 2d. Thus, the fixing device 9 is clamped firmly on the web 2a. If the screws 14 should, fail, the fixing part 9a still remains fixed in the T-shaped groove 2d. In order to transfer more safely the clamping forces of the screws 14 to the top of the web 2a of the T-shaped groove 2d or the top of the rail 2a, a rectangular frame-like abutment 21 is provided, being arranged above the bores 15 in the fixing part 9a for the screws 14 and extending from here across the top of the web 2a of the T-shaped groove 2d and the top of the rail 2a. Two screws 14 engage with the fixing part 9a at diagonally opposite corners. To receive the bores 15 for the screws 14, the frame-like fixing part 9a is extended by a bracket region for each one. Also, a lengthwise opening 12 running in the lengthwise direction of the rail 2 with a gap region 12a, serving to receive the web 2a of the rail 2, is enclosed between the abutment 21 and the first fixing part 9a by their margin regions.
This fixing device 9 can also be divided into the previously described fixing region 9d and the adjoining suspension region 9c. The suspension region 9c essentially consists of two bores 13 to receive the bolt 7, being separated by an intermediate space 16, in which the pivoting bearing 8 with the tension element 6 is recessed. The intermediate space 16 also has projections 9f protruding into it, in order to center the pivoting bearing. The bolt 7 extending through the two bores 13 and the pivoting bearing 8 has a head 7c at one end, which is held without twisting by a recess in the abutment 21 and held in the bore 13. In the region of the bores 13, the otherwise flat fixing part 9a is thickened vertically in the manner of pillow blocks. These pillow blocks extend upward from the T-shaped groove 2d.
In regard to the configuration of the pivoting bearing 8, refer to the description for
Also, the aforementioned sample embodiment describes the preferred use of the suspension 1 with single-beam overhead cranes, namely, between the rail 2 and the travel rail 3. This new suspension 1, of course, is also suitable for suspending the travel rails 3 from suitable support structures or other rails 2. The rail 2 can also be I-shaped.
Number | Date | Country | Kind |
---|---|---|---|
102005047205.2 | Oct 2005 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP2006/065073 | 8/4/2006 | WO | 00 | 3/27/2008 |