braking device

Abstract

Braking device (2) for a carriage (1) of a gravity conveyor, comprising: a shaft (4) for connecting to a running wheel (1.1, 1.2) of the carriage (1) in order to drive the shaft (4) in rotation via a rotational movement of the running wheel (1.1, 1.2), a fluid passage (10) for conducting a hydraulic fluid, a hydraulic pump (20) which is drivingly connected to the shaft (4) and which is integrated into the fluid passage (10) in order to convey the hydraulic fluid through the fluid passage (10), and a throttle (30) which is integrated into the fluid passage (10) and which is configured to throttle a flow rate of the hydraulic fluid through the fluid passage (10) by means of a variable throttle passage cross-section (33, 75, 34, 76) depending on a delivery rate of hydraulic fluid, characterized in that the throttle (30) has a bypass passage (54, 55, 56, 57, 61, 63, 64, 71), via which hydraulic fluid can be passed through the throttle (30), bypassing the throttle passage cross-section (33, 75, 34, 76), wherein a valve is integrated into the bypass passage (54, 55, 56, 57, 61, 63, 64, 71), via which valve a flow cross-section of the bypass passage (54, 55, 56, 57, 61, 63, 64, 71) can be adjusted, wherein the braking device (2) has a housing (3), in which the hydraulic pump (20), the throttle (30) and the fluid passage (10) are arranged and through which the shaft (4) extends under rotatable mounting, and an adjusting mechanism (40), via which the valve is adjustable to adjust its flow cross-section, and wherein a drive section (41) of the adjusting mechanism (40) is arranged on an outer side of the housing (3), and wherein the adjusting mechanism (40) has a display (42),which is arranged on the outside of the housing (3) and via which a setting of the valve can be read.,

Description

The invention relates to a braking device for a carriage of a gravity conveyor, which braking device is designed according to the preamble of claim 1.A brake device of the type mentioned at the beginning is known, for example, from DE 10 2012 011 485 A1.In the case of gravity conveyors, such as, for example, gravity hangers, the driving force acting for the carriages, which roll on a rail system, for example, is exclusively gravity. In order to be able to hold the carriages in a specific travel speed range, so that they travel reliably along the rail system without exceeding a maximum travel speed, each carriage is provided with a braking device.The braking device of a carriage of a gravity suspension conveyor known from DE 10 2012 011 485 A1 has a shaft on which two running wheels of the carriage are attached in a rotationally fixed manner in order to rotationally drive the shaft via a rotational movement of the running wheels, a fluid passage for conducting a hydraulic fluid, a hydraulic pump which is drivingly connected to the shaft and which is incorporated into the fluid passage in order to convey the hydraulic fluid through the fluid passage, and a throttle which is incorporated into the fluid passage and which is configured to throttle a flow rate of the hydraulic fluid through the fluid passage by means of a variable throttle passage cross section depending on a conveying rate of hydraulic fluid.Since an increase in the delivery rate of hydraulic fluid of the hydraulic pump is brought about as the travel speed of the carriage increases and as a result the rotational speed of the shaft increases, the flow rate of the hydraulic fluid through the fluid passage is reduced by the throttle by sequentially reducing the variable throttle passage cross section. Thus, the hydraulic pump must operate all the more against pressure as the travel speed of the carriage increases, whereby the rotation of the shaft and thus also the carriage are braked. In this case, by changing a spring prestress of a throttle element of the throttle arranged in the fluid passage, a throttle effect or brake characteristic can be adapted to different operating conditions. However, this possibility of changing or adapting the braking characteristic is relatively limited.DE 10 2004 061 990 B4 shows a suspension track system for transporting objects. This comprises at least one support rail with at least one section inclined with respect to a horizontal plane, at least one drive means and at least one support frame which receives an object and is connected to the drive means and is guided movably by the support rail. The support frame is pivotable about a horizontal pivot axis which is substantially perpendicular to its direction of movement. In addition, a method for operating such a suspension track system is proposed, wherein, in the method, a swinging of the supporting frame about the pivot axis is prevented by a brake device.DE 27 58 234 A1 discloses a brake valve for load-independent speed control of traction-loaded double-acting pressure-medium-operated motors, which comprises the following features:a single- or multi-part stepped piston is guided in the housing of the brake valve, which piston is provided with an adjustable main throttle closed in the initial position and is acted upon by a compression spring in the closing direction of the adjustable main throttle;the motor connection and the outlet connection of the brake valve are connected to each other via the throughflow cross section of the main throttle which increases depending on the actuating path;the main throttle is connected in parallel with a bypass check valve which is connected in the connecting line located behind the engine in the direction of action of the external load and opens in the direction of the engine.EP 0 639 119 B1 relates to a machine tool having a headstock and at least one tool changer which transports machining tools between a magazine position and a working position, wherein the tool changer is assigned, as a drive unit, at least one fluidically actuatable working cylinder having a cylinder housing in which a piston is arranged so as to be axially movable, a damping device being provided for the fluidic end position damping thereof.AT 378 159 B shows a braking device for a vehicle, having a pump which is driven by a wheel of the vehicle to be braked and is preferably designed as a gear pump and is arranged in a closed hydraulic circuit in which an adjustable throttle element and preferably a pressure relief valve are switched on, wherein a clutch is arranged between the wheel to be braked and the pump, wherein the hydraulic circuit accommodates the pump, the throttle element and optionally the pressure relief valve in a housing which is preferably fastened to the frame of a bicycle by means of a mounting plate, wherein a sprocket which is drivable by a further sprocket which is connected to one of the wheels of the bicycle, preferably the rear wheel, in a couplable manner, via a chain is fixedly mounted on the pump shaft, and wherein the throttle element is connected to an adjusting lever which can be actuated by the rider.DE 32 25 132 A1 relates to a hydraulic safety brake valve in the lines of a double-acting hydraulic consumer under preload, having a stroke line which connects the pump to the stroke side of the consumer for operating the consumer against the preload and having a lowering line which connects the pump to the lowering side of the consumer for operating the consumer with the preload, which safety brake valve controls the stroke line when the consumer is operating in the direction of the preload, wherein the safety brake valve consists of a throttle valve in the stroke line and a flow meter in the lowering line, wherein the throttle valve is controlled by the flow meter in the opening direction with an increasing flow rate and in the closing direction with a decreasing flow rate.The invention is based on the object of developing a braking device designed according to the preamble of claim 1 in such a way that its braking characteristic can be set more flexibly and, as a result, a travel speed window of a carriage provided with the braking device can be better adapted to the respective use conditions.This is achieved with a brake device according to claim 1. Further developments of the invention are defined in the dependent claims.According to the invention, a braking device for a carriage of a gravity conveyor comprises: a shaft for connecting to an impeller of the carriage in order to drive the shaft in rotation via a rotational movement of the impeller; a fluid passage for conducting a hydraulic fluid; a hydraulic pump which is drive-connected to the shaft and which is incorporated into the fluid passage in order to convey the hydraulic fluid through the fluid passage; and a throttle which is incorporated into the fluid passage and which is configured to throttle a flow rate of the hydraulic fluid through the fluid passage by means of a variable throttle passage cross section depending on a conveying rate of hydraulic fluid.The brake device according to the invention is characterized in that the throttle has a bypass passage via which hydraulic fluid can be conducted through the throttle while bypassing the throttle passage cross section, wherein a valve is integrated into the bypass passage, via which valve a flow cross section of the bypass passage can be adjusted.An additional fluid flow is permitted through the throttle through the bypass passage, this additional fluid flow being adjustable in terms of its flow rate via the valve integrated into the bypass passage. As a result, the braking characteristic of the braking device realized via the hydraulic dynamic pressure in the fluid passage can be set more flexibly, as a result of which a travel speed window of a carriage provided with the braking device can be better adapted to the respective use conditions.The throttle is preferably set up such that the throttle passage cross section is reduced with an increasing delivery rate of hydraulic fluid. Thus, as the delivery rate of hydraulic fluid increases, the flow rate of hydraulic fluid realized via the throttle passage cross section of the throttle is reduced.The throttle is preferably set up such that hydraulic fluid can be conducted through the throttle via the bypass passage only from a specific delivery rate. This takes into account that the throttle only begins with the delivery-rate-dependent throttling of the flow rate of the hydraulic fluid through the fluid passage starting from a specific delivery rate. Thus, the flow rate of hydraulic fluid possible via the bypass passage counteracts or cancels the delivery rate-dependent throttling to the desired extent.According to the invention, the brake device further comprises a housing in which the hydraulic pump, the throttle and the fluid passage are arranged and through which the shaft extends under rotatable mounting, and an adjustment mechanism via which the valve is adjustable for adjusting its flow cross section, wherein a drive section of the adjustment mechanism is arranged on an outer side of the housing.By arranging the drive section of the adjustment mechanism on the outer side of the housing of the brake device, the adjustment of the flow cross section and thus of the enabled flow rate of the bypass passage can be carried out comfortably and quickly.According to the invention, the adjustment mechanism has a display which is arranged on the outer side of the housing and by means of which an adjustment of the valve can be read. The setting of the valve or flow cross section and thus of the enabled flow rate of the bypass passage on the outer side of the housing can thus be read off quickly and comfortably and set accurately and reproducibly. Preferably, the display includes a scale fixed to the outside of the housing and a pointer that points to the scale and that is fixed to the driving portion.According to yet another embodiment of the invention, the braking device also has a locking device which can be selectively set into a blocking state in which the locking device blocks the actuating mechanism against an adjustment of the valve and into a release state in which the locking device releases the actuating mechanism for an adjustment of the valve, wherein the locking device has a control section which is arranged on the outer side of the housing and via which the blocking state and the release state of the locking device can be realized.The locking device thus formed advantageously ensures the setting of the valve or flow cross section and thus of the enabled flow rate of the bypass passage, so that it does not unintentionally adjust itself. By arranging the control portion on the outside of the housing, this fuse can be manufactured and released quickly and comfortably.According to a further embodiment of the invention, the throttle comprises a throttle housing with a tubular throttle housing interior, a tubular guide part with a guide part interior and a piston. The guide part is inserted into the throttle housing interior space, so that an intermediate space is defined between the guide part and the throttle housing. The piston is accommodated on an outer circumference of the guide part so as to be longitudinally displaceable, so that a gap is defined between the piston and the throttle housing, which gap is a component of a throttle passage having the variable throttle passage cross section through the intermediate space. An aperture is provided in a wall of the guide part towards the guide part interior, so that the bypass passage extends through the aperture and in the guide part interior. Rotatably inserted into the guide part interior is a valve element which is rotationally adjustable via an adjustment mechanism and which, together with the wall of the guide part, forms the valve for adjusting the flow cross section of the bypass passage. This embodiment of the invention implements in a simple and compact or space-saving manner the valve for adjusting the flow cross section of the bypass passage.According to yet another embodiment of the invention, the throttle comprises a throttle housing, a tubular guide part, a sleeve-shaped piston and spring means. The throttle housing has a tubular throttle housing interior. The guide part having a guide part interior is inserted into the throttle housing interior, so that an intermediate space is defined between the guide part and the throttle housing. Two opposite longitudinal ends of the intermediate space are preferably each defined by a radially inward shoulder of the throttle housing. The piston is accommodated sealingly and longitudinally displaceably on an outer periphery of the guide part. An outer circumference of the piston is dimensioned such that a gap is defined between the piston and the throttle housing. The spring means are arranged in the intermediate space, so that the piston is placed under spring tension in a neutral region between the longitudinal ends of the intermediate space.The throttle housing has a housing taper narrowing the intermediate space between the neutral region and at least one of the longitudinal ends of the intermediate space. The housing bevel is provided in order to define a sealing valve seat for a respective piston bevel of the piston running between the outer circumference and an end side facing the respective longitudinal end of the intermediate space when the piston is moved out of the neutral region, so that the variable throttle passage cross section is formed between the housing bevel and the piston bevel.In a wall of the throttle housing, on the longitudinal end side of each valve seat-defining housing bevel, a fluid passage is formed in each case between each of the longitudinal ends and the neutral region of the interspace, to which the fluid passage is connected. On the longitudinal end side of each valve seat-defining housing bevel, an aperture is provided in a wall of the guide part towards the guide part interior with a partially circumferential extent, which aperture runs along the guide part as far as into the neutral region of the intermediate space, so that the bypass passage extends through the aperture and in the guide part interior.According to this embodiment of the invention, the bypass passage is advantageously realized by utilizing the guide part interior of the guide part guiding the piston in the throttle housing, whereby the throttle can be made compact as a whole. Because the guide part is tubular, i.e. designed as a hollow body, the weight of the throttle can be reduced.According to yet another embodiment of the invention, a valve element is rotatably inserted into the guide part interior, which valve element is connected to the drive section of the actuating mechanism and which valve, together with the wall of the guide part, forms the valve for adjusting the flow cross section of the bypass passage. This embodiment of the invention implements in a simple and compact or space-saving manner the valve for adjusting the flow cross section of the bypass passage.According to one embodiment of the invention, the brake device also has an adjusting shaft which forms the adjusting mechanism and is rotatably inserted into the guide part interior of the guide part. The adjustment shaft has a longitudinal end providing the drive portion of the adjustment mechanism and a seal portion whose outer periphery is sized to sealingly mate with the wall of the guide member. In the sealing section of the adjusting shaft, at least one recess section is provided, which is recessed with respect to the outer periphery of the sealing section and which extends longitudinally corresponding to the at least one aperture of the wall of the guide part. In this case, the recess portion is provided in the sealing portion at least along a part of its continuous length with a partially circumferential extent, such that the valve element is formed.By providing the recess portion, hydraulic fluid can advantageously flow in the recess portion as a constituent part of the bypass passage. By providing the subsection of the depression section with a partially circumferential extension, the valve element which can be adjusted by rotation in the guide part interior can be provided in a simple manner. Preferably, the partially circumferential extension of the recess section corresponds to the partially circumferential extension of the at least one aperture in the wall of the guide part. The full partial circumferential extent of the at least one aperture is thus advantageously used for the full throughflow cross section of the bypass passage and the effect thereof for partially cancelling the throttle effect is thus increased.According to a further embodiment of the invention, the recess section is provided along a part of its length with a full extent in the sealing section, wherein the part of the recess section formed with a partial extent is formed starting from the neutral region so long that it overlaps with the piston when the piston is seated in the valve seat moved out of the neutral region.By providing the subsection of the depression section with a full extent, a rotational resistance during the adjustment of the actuating shaft or of the valve of the bypass passage can advantageously be reduced due to the smaller friction surface between the actuating shaft and the guide part. The overlap as described nevertheless allows the valve action for the throughflow cross section of the bypass passage to be ensured.The invention also provides a carriage for a gravity conveyor, wherein the carriage is provided with a braking device according to one, more or all of the embodiments of the invention described above in any conceivable combination.The invention expressly also extends to such embodiments which are not given by combinations of features from explicit references back to the claims, whereby the disclosed features of the invention can be combined with one another as desired, insofar as this is technically expedient.The invention will be described below with reference to preferred embodiments and with reference to the attached figures. FIG. 1 shows a perspective view of a braking device, designed according to an embodiment of the invention, of a carriage for a gravity conveyor. FIG. 2 shows a sectional view of the carriage of FIG. 1, viewed along a line A-A in FIG. 1 defining a vertical sectional plane. FIG. 3 is a broken-away sectional view of the carriage of FIG. 1, as viewed along a line B-B in FIG. 1 defining a vertical sectional plane. FIG. 4 ashows a sectional view of a throttle of the brake device of the carriage of FIG. 1, viewed along a line C-C in FIG. 1 defining a vertical sectional plane. FIG. 4 bshows a sectional view of the throttle of the brake device of the carriage of FIG. 1, viewed along a vertical sectional plane rotated through 90 degrees with respect to the vertical sectional plane of FIG. 4 a. FIG. 5 shows a perspective view of components of the throttle of the brake device of the carriage of FIG. 1. FIG. 6 ashows a sectional view of a locking device and an adjustment mechanism of the throttle of the braking device of the carriage of FIG. 1, viewed along a line D-D in FIG. 4 adefining a horizontal sectional plane. FIG. 6 bshows a top view of the locking device and of the adjustment mechanism of the throttle of the braking device of the carriage of FIG. 1.FIG. 1 shows a perspective view of a braking device 2 of a carriage 1 for a gravity conveyor (not shown), such as a gravity overhead conveyor, which carriage is designed according to one embodiment of the invention.The brake device 2 has a housing 3 and a shaft 4 which extends through the housing 3 with rotatable mounting, so that the shaft 4 protrudes out of the housing 3 at two lateral sides of the housing 3 facing away from one another with two longitudinal end sections of the latter. Two running wheels 1.1, 1.2 of the carriage 1 are attached to these longitudinal end sections in a rotationally fixed manner, so that the shaft 4 is rotationally driven by a rotational movement of the running wheels 1.1, 1.2 which is caused when the carriage 1 runs on a rail system of the gravity conveyor.As shown in FIGS. 2 to 6, the brake device 2 further includes a fluid passage 10 formed in the housing 3 and filled with hydraulic fluid (not shown) sent from the fluid passage 10 in the endless cycle, and a hydraulic pump 20 and a throttle 30 connected in series to each other, respectively, in the fluid passage 10.The hydraulic pump 20 is designed as a gear pump and has a drive gearwheel 21, which is mounted on the shaft 4 and is drive-connected to the latter in a rotationally fixed manner, and a driven gearwheel 22, which is mounted rotatably on a further shaft 4.1 mounted in the housing 3 and which meshes with the drive gearwheel 21 in a section of the fluid passage 10. Depending on the direction of rotation of the impellers 1.1, 1.2 and thus of the drive gearwheel 21, the hydraulic fluid located in the fluid passage 10 can thus be conveyed under pressure through the fluid passage 10 either clockwise or counter-clockwise with respect to FIG. 2.As can be seen from FIGS. 2 and 3, two partial sections 11, 12 of the fluid passage 10 extend with respect to their longitudinal course approximately parallel to the longitudinal course of the shaft 4 which rotationally drives the drive gearwheel 21 in the housing 3. In other words, the throttle 30 is incorporated into the fluid passage 10 such that it can provide fluid communication between respective ends of the two sections 11, 12 so as to realize the continuous circulation of the hydraulic fluid in the fluid passage 10.The throttle 30 is configured to throttle a flow rate of the hydraulic fluid through the fluid passage 10 for each delivery direction of the hydraulic pump 20 by means of a variable throttle passage cross section as a function of a delivery rate of hydraulic fluid. More specifically, as the traveling speed of the traveling truck 1 increases and the rotational speed of the drive gear 21 of the hydraulic pump 20 increases, resulting in an increase in the delivery rate of hydraulic fluid, the flow rate of the hydraulic fluid through the fluid passage 10 is reduced by sequentially decreasing the variable throttle passage area. Thus, the hydraulic pump 20 must operate all the more against pressure as the travel speed of the carriage 1 increases, whereby the rotation of the shaft 4 and thus also the carriage 1 is braked.In order to be able to set the braking characteristic provided by the throttle 30 better and thus to give the carriage 1 a travel speed window better adapted to the respective operating conditions, the throttle 30 has a bypass passage for each delivery direction of the hydraulic pump 20, via which hydraulic fluid can be passed through the throttle 30, preferably starting from a specific delivery rate of hydraulic fluid, while bypassing the throttle passage cross section.Integrated into each bypass passage is a valve, by means of which a flow cross section of the bypass passage is adjustable. For this purpose, the throttle 30 has an adjustment mechanism 40, by means of which the valve is adjustable for adjusting its flow cross section. In order to allow adjustment of the valve from an outer side of the housing 3, the adjustment mechanism 40 has a drive portion 41 which is arranged on the outer side of the housing 3 and which can be rotationally driven by means of a matching first special key W 1.In order to be able to indicate the setting of the valve on the outside of the housing 3, the adjustment mechanism 40 also has an indicator 42 which is arranged on the outside of the housing 3 and via which the setting of the valve can be read.In order to be able to secure the adjustment of the valve from the outside of the housing 3, so that it does not unintentionally adjust, the brake device 2 also has a locking device 5. The locking device 5 is configured to be selectively adjustable into a blocking state in which the locking device 5 blocks the adjustment mechanism 40 against an adjustment of the valve and into a release state in which the locking device 5 releases the adjustment mechanism 40 for an adjustment of the valve. In order to realize the locked state and the released state of the locking device 5 from the outside of the housing 3, the locking device 5 has a control section 5 awhich is arranged on the outside of the housing 3 and which can be rotationally driven by means of a matching second special key W 2.In the following, the configuration of the brake device 2 according to the invention will be discussed in more detail with reference to FIGS. 1 to 6.As can be seen in particular from FIGS. 4 and 5, the throttle 30 has an elongate throttle housing 31, an adjusting shaft 50, an elongate tubular guide part 60 having a guide part interior 61, a sleeve-shaped or wheel-like piston 70 and spring means in the form of two identical helical compression springs 80, 81.The throttle housing 31 has an elongated tubular throttle housing inner space 32 into which the guide tubular member 60 is longitudinally inserted so that a clearance Z 1 is defined between an outer periphery (outer diameter) 62 of the guide member 60 and the throttle housing 32. Two opposite longitudinal ends Z 1.1, Z 1.2 of the intermediate space Z 1 are defined here in each case by a radially inward shoulder 31.1, 31.2, i.e. an annular collar of the throttle housing 31 projecting radially into the throttle housing interior 32.The piston 70 has a through bore 71 via which the piston 70 is received on the outer periphery 62 of the guide part 60 in a sealing and longitudinally displaceable manner (as indicated by the double arrow in FIG. 4 a) against fluid passage. An outer circumference (outer diameter) 72 of the piston 70 is dimensioned such that a gap S 1 is defined between the outer circumference 72 of the piston 70 and the throttle housing 31.The helical compression springs 80, 81 (spring means) are arranged in the intermediate space Z 1 such that the piston 70 is placed under spring tension in a neutral region N 1 (here a central region) between the longitudinal ends Z 1.1, Z 1.2 of the intermediate space Z 1. The neutral range N 1 herein means a range in which the piston 70 is spring-biased on the guide part 60 in the throttle housing 31 when the piston 70 is not supplied with the fluid pressure by the hydraulic fluid.Between the neutral region N1 and each of the longitudinal ends Z1.1, Z1.2 of the intermediate space Z1, the throttle housing 31 has a housing taper 33, 34 which narrows the intermediate space Z1 conically towards the respective longitudinal end Z1.1, Z1.2. The piston 70 has two end faces 73, 74 which define its two longitudinal ends and are facing away from one another and which, in the assembled state (as shown in FIGS. 4 aand 4 b), each face one of the longitudinal ends Z 1.1, Z 1.2 of the intermediate space Z 1. At each of its two longitudinal ends, the piston 70 has a conical piston bevel 75, 76, which runs between the outer periphery 72 of the piston 70 and the end face 73 or 74 belonging to the respective longitudinal end.Each of the two piston slopes 75, 76 faces a respective one of the two housing slopes 33, 34, so that each of the two housing slopes 33, 34 defines a sealing valve seat for the respective facing piston slope 75, 76 when the piston 70 is moved out of the neutral region N 1. Between each housing bevel 33, 34 and the respective facing piston bevel 75 or 76, a variable throttle passage cross section is thus formed as mentioned above, with which the flow rate of the hydraulic fluid through the fluid passage 10 in a respective conveying direction of the hydraulic pump 20 can be throttled (also throttled to zero) as a function of the conveying rate of hydraulic fluid.More specifically, a fluid passage 35, 36 is formed in each case in a wall of the throttle housing 31 between each of the longitudinal ends Z 1.1, Z 1.2 and the neutral region N 1 of the intermediate space Z 1, to which passage one of the two partial sections 11, 12 of the fluid passage 10 is connected in each case. Each of the two fluid passages 35, 36 of the throttle housing 31 is arranged on the longitudinal end of the interspace (on the side of the respective longitudinal end Z1.1 or Z1.2) of the respective valve-seat-defining housing bevel 33, 34.In a first delivery direction of the hydraulic pump 20, the hydraulic fluid flows from the hydraulic pump 20 into the intermediate space Z 1 via the first fluid passage 35 that is the upper one in FIG. 4, flows through the gap S 1, and then flows out from the intermediate space Z 1 via the second fluid passage 36 that is the lower one in FIG. 4 to flow back to the hydraulic pump 20. The hydraulic fluid in the intermediate space Z 1 thereby presses on the upper end face 73 of the piston 70 in FIG. 4 Starting from a certain delivery rate of hydraulic fluid, the piston 70 is thereby pressed against the spring force of the helical compression spring 81 that is lower in FIG. 4 in the direction of the housing bevel 34 that is lower in FIG. 4. If the delivery rate is so great that the lower piston bevel 76 in FIG. 4 comes to rest in the lower housing bevel 34 in FIG. 4, the flow rate of the hydraulic fluid that can be realized via the gap S 1 is throttled to zero.In a second delivery direction of the hydraulic pump 20, the hydraulic fluid flows from the hydraulic pump 20 into the clearance Z 1 via the second fluid passage 36, flows through the gap S 1, and then flows out from the clearance Z 1 via the first fluid passage 35 to again flow to the hydraulic pump 20. The hydraulic fluid in the intermediate space Z 1 thereby presses on the lower end face 74 of the piston 70 in FIG. 4 Starting from a certain delivery rate of hydraulic fluid, the piston 70 is thereby pressed against the spring force of the upper helical compression spring 80 in FIG. 4 in the direction of the upper housing bevel 33 in FIG. 4. If the delivery rate is so great that the upper piston bevel 75 in FIG. 4 comes to rest in the upper housing bevel 33 in FIG. 4, the flow rate of the hydraulic fluid that can be realized via the gap S 1 is throttled to zero.As mentioned above, the throttle 30 has a bypass passage for each delivery direction of the hydraulic pump 20 in order to be able to better set the braking characteristic provided by the throttle 30 and thus to be able to give the carriage 1 a travel speed window which is better adapted to the respective operating conditions.More precisely, two slot-shaped, identically dimensioned apertures 63, 64 are provided in a wall of the guide part 60 towards the guide part interior 61. The two apertures 63, 64 are arranged in a line along the guide part 60, a non-perforated wall part 65 remaining between the two apertures 63, 64. Each of the apertures 63, 64 has a partially circumferential extension (slot width) with respect to the outer periphery 62 of the guide part 60. Each of the apertures 63, 64 is also arranged along the guide part 60 and has a length (slot length) along the guide part 60 such that, in the assembled state of the throttle 30 (as shown in FIG. 4 ), it extends, starting at the longitudinal end of the interspace, on the side of a respective valve-seat-defining housing bevel 33, 34, as far as into the neutral region N 1 of the interspace Z 1. The non-punctured wall part 65 is arranged in the neutral region N 1 and each bypass passage extends through one of the two apertures 63, 64 and in the guide part interior 61.Rotatably inserted into the guide part interior 61 for each bypass passage is a valve element which is connected to the drive section 41 of the actuating mechanism 40 and which, together with the wall of the guide part 60, forms the valve for adjusting the flow cross section of the bypass passage.More specifically, the adjustment shaft 50 of the throttle 30 constitutes the adjustment mechanism 40, and is rotatably inserted into the guide part inner space 61 of the guide part 60. The adjusting shaft 50 has a longitudinal end 51 which provides the drive section 41 of the adjusting mechanism 40, and a sealing section 52, 53 whose outer periphery 52 a, 53 a(outer diameter) is dimensioned such that it sealingly fits with the wall of the guide part 60 against fluid passage.In an upper portion of the sealing section 52, 53 in FIGS. 4 and 5, a first recess section 54, 55 is provided, which is recessed with respect to the outer periphery 52 a, 53 aof the sealing section 52, 53 and which extends along the adjusting shaft 50, so that the first recess section 54, 55 in the assembled state (see FIG. 4 ) runs in the wall of the guide part 60 in accordance with the upper aperture 63 in FIGS. 4 and 5. That is, the first recess section 54, 55 has such a length that, in the assembled state, it extends approximately congruently with the upper aperture 63 on the longitudinal end side of the upper housing bevel 33, starting at the intermediate space, as far as into the neutral region N 1 of the intermediate space Z 1, as shown in FIG. 4 a.The first recess portion 54, 55 is provided along a groove-like subsection 55 of its continuous length with a partial circumferential extension in the sealing portion 52, 53, so that the valve element for adjusting the flow cross section is formed for the one (upper) bypass passage. The partially circumferential extension (width) of the partial section 55 of the first recess section 54, 55 corresponds to the partially circumferential extension (slot width) of the upper opening 63 in the wall of the guide part 60.The first recess section 54, 55 is also provided along a partial section 54 of its length with a full extension in the sealing section 52, 53. As can be seen from FIG. 4 a, the subsection 55, formed with a partial circumferential extension, of the first depression section 54, 55, starting from the neutral region N 1 is formed so long that it overlaps longitudinally with the piston 70 when the piston 70 is moved out of the neutral region N 1 and is seated in the valve seat (the upper housing bevel 33).In a lower portion of the sealing section 52, 53 in FIGS. 4 and 5, a second recess section 56, 57 is provided, which is recessed with respect to the outer periphery 52 a, 53 aof the sealing section 52, 53 and which extends along the adjusting shaft 50, so that the second recess section 56, 57 in the assembled state (see FIG. 4 ) runs in the wall of the guide part 60 in accordance with the aperture 64 which is lower in FIGS. 4 and 5. That is, the second recess section 56, 57 has such a length that, in the assembled state, it extends approximately congruently with the lower aperture 64 on the longitudinal end side of the lower housing bevel 34, starting at the intermediate space, as far as into the neutral region N 1 of the intermediate space Z 1, as shown in FIGS. 4 aand 4 b.The second recess portion 56, 57 is provided along a groove-like subsection 57 of its continuous length with a partial circumferential extension in the sealing portion 52, 53, so that the valve element for adjusting the flow cross section is formed for the other (lower) bypass passage. The partially circumferential extension (width) of the partial section 57 of the second recess section 56, 57 corresponds to the partially circumferential extension (slot width) of the lower opening 64 in the wall of the guide part 60.The second recess section 56, 57 is also provided along a partial section 56 of its length with a full extension in the sealing section 52, 53. As can be seen from FIG. 4 a, the subsection 57 of the second depression section 56, 57 formed with a partial circumferential extension is formed starting from the neutral region N 1 so long that it overlaps longitudinally with the piston 70 when the piston 70 is moved out of the neutral region N 1 and is seated in the valve seat (the lower housing bevel 34).A non-recessed part of the sealing section 52, 53 remains between the two partial sections 55, 57 formed with partial circumferential extension, wherein the non-recessed part of the sealing section 52, 53 corresponds approximately in arrangement and dimension to the non-perforated wall part 65 of the guide part 60.By rotating the adjusting shaft 50 and thus the valve elements formed by the partial sections 55, 57 formed with partial circumferential extension with respect to the apertures 63, 64 of the guide part 60, the flow cross section of both bypass passages can be adjusted simultaneously (and to the same value).In order to be able to indicate the setting of the valve elements formed by the subsection 55, 57 from the outside of the housing 3, the display 42 of the adjustment mechanism 40 is provided on the outside of the housing 3. As shown in FIG. 6 b, the display 42 includes a scale 43 fixed to the outside of the housing 3 and a pointer 44 that points to the scale 43 and that is fixed to the driving portion 41. Thus, a rotation angle of the adjusting shaft 50 with respect to the guide member 60 and thus the adjustment of the valves of the bypass passages can be read and accurately adjusted.In order to be able to secure the setting of the valve elements formed by the subsection 55, 57 from the outside of the housing 3, so that the latter is not unintentionally adjusted, the locking device 5 is provided on the outside of the housing 3. As can be seen from FIG. 6a, the control section 5a is designed as a head of an internal hexagon screw 6 which is screwed into a threaded piece 7 mounted on the outer side of the housing 3.The threaded piece 7 has a transmission chamber 7a into which the longitudinal end of the hexagonal socket screw 6 remote from the control section 5a (head) extends. A plunger 8 is arranged in the transmission chamber 7 ain such a way that a head end 8 aof the plunger 8 can be brought into sliding engagement with the longitudinal end of the hexagon socket screw 6 facing away from the control section 5 a(head). The plunger 8 extends therein in a slidingly mounted manner through the threaded piece 7, so that a free longitudinal end 8b, which ends in a tip, engages the toothing 51a thereof provided in an outer circumferentially on the longitudinal end 51 of the adjusting shaft 50, which longitudinal end is provided with the drive section 41. In the transmission chamber 7a, a helical compression spring 9 is also arranged in such a way that it pretensions the head end 8a of the plunger 8 towards the adjusting shaft 50 and thus presses the longitudinal end 8b, which ends at a point, resiliently into the toothing 51a.If the hexagon socket screw 6 is now unscrewed from the threaded piece 7 via the control section 5 ato such an extent that the plunger 8 can move into the transmission chamber 7 aagainst the spring force of the helical compression spring 9 by a measure corresponding to a depth of the toothing 51 a, the release state of the locking device 5 is established and the setting of the valve elements formed by the subsection 55, 57 on the actuating shaft 50 can be changed in a ratchet-like manner by rotationally driving the drive section 41 of the actuating mechanism 40.If the hexagonal socket screw 6 is screwed back into the threaded piece 7 via the control section 5 ato such an extent that the longitudinal end of the hexagonal socket screw 6 facing away from the control section 5 a(head) is in sliding engagement with the head end 8 aof the plunger 8 and its longitudinal end 8 b, which runs out in a tip, presses completely and rigidly into the toothing 51 a, the locked state of the locking device 5 is established.If the hydraulic pump 20 is now operated in the first conveying direction as described above and a conveying rate is reached, so that the piston 70 moves out of the neutral range N 1 and in the direction toward the housing bevel 34 which is at the bottom in FIG. 4, the piston 70 releases the opening 64, which is at the bottom in FIG. 4, of the guide part 60 starting in the neutral range N 1 starting from a specific amount of movement (which corresponds to the conveying rate). If the subsection 57 of the second depression section 56, 57 forming the valve element is now aligned congruently with the opening 64 of the guide part 60 that is at the bottom in FIG. 4, the hydraulic fluid with a full flow cross section can flow through the lower bypass passage, bypassing the variable throttle passage cross section (lower housing slope 34 in FIG. 4 in cooperation with the piston slope 76 that is at the bottom in FIG. 4 ) to the second fluid passage 36, in order to flow back to the hydraulic pump 20. At this time, the lower bypass passage is formed by the lower hole 64 in FIG. 4, the second recessed portion 56, 57, a part of the guide part internal space 61, and a part of the wall of the through hole 71 of the plunger 70.In order to reduce the flow cross section of the lower bypass passage, the actuating shaft 50 is rotationally actuated via the drive section 41 so that the partial section 57 of the second recess section 56, 57 forming the valve element is rotated or disaligned to a certain extent with respect to the opening 64 of the guide part 60 which is lower in FIG. 4.If the hydraulic pump 20 is operated in the second delivery direction as described above and a delivery rate is reached so that the piston 70 moves out of the neutral range N 1 and in the direction toward the upper housing bevel 33 in FIG. 4, the piston 70 releases the upper opening 63 of the guide part 60 starting in the neutral range N 1 starting from a specific amount of movement (which corresponds to the delivery rate). If the subsection 55 of the first depression section 54, 55 forming the valve element is now aligned congruently with the upper aperture 63 of the guide part 60 in FIG. 4, the hydraulic fluid with full throughflow cross section can flow through the upper bypass passage, bypassing the variable throttle passage cross section (upper housing bevel 33 in FIG. 4, interacting with the upper piston bevel 75 in FIG. 4 ) to the first fluid passage 35 in order to flow back to the hydraulic pump 20. At this time, the upper bypass passage is formed by the upper hole 63 in FIG. 4, the first recessed portion 54, 55, a part of the guide part internal space 61, and a part of the wall of the through hole 71 of the plunger 70.In order to reduce the flow area of the upper bypass passage, the actuating shaft 50 is rotationally actuated via the drive section 41 so that the partial section 55 of the first recess section 54, 55, which forms the valve element, is rotated or disaligned to a certain extent with respect to the opening 63 of the guide part 60 which is the upper opening in FIG. 4.List of reference characters1 Carriage 1.1 Impeller 1.2 Impeller 2 Braking device 3 Housing 4 Shaft 4.1 Shaft 5 Locking device 5 aControl section 6 Hexagon socket screw 7 Threaded piece 7 aTransmission chamber 8 Plunger 8 aHead end 8 b Längs end 9 Helical compression spring 10 Fluid passage 11 Subsection 12 Subsection 20 Hydraulic pump 21 Drive gearwheel 22 Driven gearwheel 30 Throttle 31 Throttle housing 31.1 Shoulder 31.2 Shoulder 32 Throttle housing interior 33 Housing bevel 34 Housing bevel 35 Fluid passage 36 Fluid passage 40 Adjustment mechanism 41 Drive section 42 Display 43 Scale 44 Pointer 50 Adjustment shaft 51 Longitudinal end 51 a Verzahnung 52, 53 Sealing section 52 a, 53 aouter circumference 54 first recess portion (subsection) 55 first recess portion (subsection) 56 second recess portion (subsection) 57 second recess portion (subsection) 60 guide part 61 guide part interior 62 outer circumference 63 opening 64 opening 65 non-perforated wall part 70 piston 71 through bore 72 outer circumference 73 end face 74 end face 75 piston bevel 76 piston bevel 80 helical compression spring 81 helical compression spring N 1 neutral region S 1 gap Z 1 intermediate space Z 1.1 longitudinal end Z 1.2 longitudinal end W 1 special key W 2 special key

Claims

Brake device (2) for a carriage (1) of a gravity conveyor, comprising: a shaft (4) for connecting to an impeller (1.1, 1.2) of the carriage (1) in order to drive the shaft (4) in rotation via a rotational movement of the impeller (1.1, 1.2), a fluid passage (10) for conducting a hydraulic fluid, a hydraulic pump (20) which is drive-connected to the shaft (4) and which is incorporated into the fluid passage (10) in order to convey the hydraulic fluid through the fluid passage (10), and a throttle (30) which is incorporated into the fluid passage (10) and which is configured to throttle a flow rate of the hydraulic fluid through the fluid passage (10) by means of a variable throttle passage cross section (33, 75, 34, 76) as a function of a conveying rate of hydraulic fluid, characterized in that the throttle (30) a bypass passage (54, 54, 7), 55, 56, 57, 61, 63, 64, 71) via which hydraulic fluid can be passed through the throttle (30) bypassing the throttle passage cross section (33, 75, 34, 76), wherein a valve is integrated into the bypass passage (54, 55, 56, 57, 61, 63, 64, 71) via which a flow cross section of the bypass passage (54, 55, 56, 57, 61, 63, 64, 71) can be adjusted, wherein the brake device (2) has a housing (3) in which the hydraulic pump (20), the throttle (30) and the fluid passage (10) are arranged and through which the shaft (4) extends under rotatable mounting, and an adjusting mechanism (40) via which the valve can be adjusted for adjusting its flow cross section, and wherein a drive section (41) of the adjusting mechanism (40) is arranged on an outer side of the housing (3), and wherein the adjusting mechanism (40) has a display (42), which is arranged on the outside of the housing (3) and by means of which an adjustment of the valve can be read.The brake device (2) according to claim 1, wherein the indicator (42) includes a scale (43) fixed to the outside of the housing (3) and a pointer (44) that points to the scale (43) and that is fixed to the driving portion (41).Brake device (2) according to one of claims 1 or 2, further comprising a locking device (5) which can be selectively set into a blocking state in which the locking device (5) blocks the adjustment mechanism (40) against an adjustment of the valve and into a release state in which the locking device (5) releases the adjustment mechanism (40) for an adjustment of the valve, wherein the locking device (5) has a control section (5a) which is arranged on the outside of the housing (3) and via which the blocking state and the release state of the locking device (5) can be realized.Brake device (2) according to one of Claims 1 - 3, wherein the throttle (30) has: a throttle housing (31) having a tubular throttle housing interior (32), a tubular guide part (60) which is inserted into the throttle housing interior (32) such that a space (Z1) is defined between guide part (60) and throttle housing (31) and which has a guide part interior (61), a sleeve-shaped piston (70) which is accommodated in a sealing and longitudinally displaceable manner on an outer circumference (62) of the guide part (60) and the outer circumference (72) of which is dimensioned such that a gap (S1) is defined between piston (70) and throttle housing (31), and spring means (80, 81) which are arranged in the space (Z1), so that the piston (70) is placed under spring tension in a neutral region (N1) between two opposite longitudinal ends (Z1.1, Z1.2) of the intermediate space (Z1), wherein the throttle housing (31) has, between the neutral region (N1) and at least one of the longitudinal ends (Z1.1, Z1.2) of the intermediate space (Z1), a housing bevel (33, 34) which narrows the intermediate space (Z1) and is provided to define a sealing valve seat for a respective piston bevel (75, 76) of the piston (70) running between the outer periphery (72) and an end face (73, 74) facing the respective longitudinal end (Z1.1, Z1.2) of the intermediate space (Z1) when the piston (70) is moved out of the neutral region (N1), such that the variable throttle passage cross section is formed between the housing bevel (33, 34) and the piston bevel (75, 76), wherein a fluid passage (35, 36) is formed in each case in a wall of the throttle housing (31) on the longitudinal end side of the interspace of each valve seat-defining housing bevel (33, 34) between each of the longitudinal ends (Z1.1, Z1.2) and the neutral region (N1) of the interspace (Z1), to which the fluid passage (10) is connected, and wherein an aperture (63, 64) is provided in a wall of the guide part (60) towards the guide part interior (61) with a partial circumferential extent on the longitudinal end side of the interspace of each valve seat-defining housing bevel (33, 34), which aperture runs along the guide part (60) as far as into the neutral region (N1) of the interspace (Z1), such that the bypass passage extends through the aperture (63, 64) and in the guide part interior (61).Brake device (2) according to claim 4, wherein a valve element is rotatably inserted into the guide part interior (61), which valve element is connected to the drive section (41) of the adjustment mechanism (40) and which valve, together with the wall of the guide part (60), forms the valve for adjusting the flow cross section of the bypass passage.Brake device (2) according to claim 5, comprising an adjusting shaft (50) forming the adjusting mechanism (40), which is rotatably inserted into the guide part interior (61) of the guide part (60) and which has a longitudinal end (51) providing the driving portion (41) of the adjusting mechanism (40), a sealing portion (52, 53), the outer periphery (52a, 53a) of which is dimensioned such that it sealingly fits with the wall of the guide part (60), and in the sealing portion (52, 53) at least one recess portion (54, 55, 56, 57), which is recessed with respect to the outer periphery (52a, 53a) of the sealing portion (52, 53) and which extends longitudinally corresponding to the at least one aperture (63, 64) of the wall of the guide part (60), wherein the recess portion (54, 55, 56, 57) at least along a part (55, 55, 57) of its continuous length with partial circumferential extension is provided in the sealing section (52, 53), so that the valve element is formed.Brake device (2) according to claim 6, wherein the partially circumferential extension of the recess portion (54, 55, 56, 57) corresponds to the partially circumferential extension of the at least one aperture (63, 64) in the wall of the guide part (60).Brake device (2) according to Claim 6 or 7, wherein the recess portion (54, 55, 56, 57) is provided along a part (54, 56) of its length with a fully circumferential extent in the sealing portion (52, 53), and wherein the part (55, 57) of the recess portion (54, 55, 56, 57), which part is formed with a partially circumferential extent, is formed starting from the neutral region (N1) so long that it overlaps with the piston (70) when the piston (70) is seated in the valve seat and is moved out of the neutral region (N1).

Images