CN218319300U

CN218319300U - Callus on sole automatic feed mechanism of callus on sole equipment

Info

Publication number: CN218319300U
Application number: CN202222156749.8U
Authority: CN
Inventors: 廖新明; 石杰; 凌斌; 李成泉
Original assignee: Dongguan Mingji Intelligent Equipment Co ltd
Current assignee: Dongguan Mingji Intelligent Equipment Co ltd
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2023-01-17
Anticipated expiration: 2032-08-16

Abstract

The utility model discloses a callus on sole automatic feed mechanism of callus on sole equipment, callus on sole feed mechanism includes: the flexible vibration material tray is used for placing the foot pad, and the Y-axis discharging modules are arranged on two sides of the flexible vibration material tray, and the other end of each Y-axis discharging module extends towards the direction of the foot pad transferring mechanism; a group of X-axis discharging modules are arranged on the Y-axis discharging module; a group of material taking modules are arranged on the X-axis material discharging module; callus on sole shifts mechanism includes: the material receiving device and four groups of material transferring rails connected with the material receiving device; wherein, a foot pad material transferring device is arranged at the tail end of the material transferring rail; realize the automatic material loading work of callus on the sole product, realize the turn-over of callus on the sole, inhale and angle fine setting work by callus on the sole feed mechanism in the in-process of processing, the slope upset of callus on the sole is realized to rethread callus on the sole transfer mechanism to send out the callus on the sole and accomplish whole automatic feed flow, processing degree of automation is high, and the precision of callus on the sole material loading is higher, makes the processingquality of follow-up assembly processing higher.

Description

Callus on sole automatic feed mechanism of callus on sole equipment

Technical Field

The utility model belongs to the technical field of quick-witted case callus on sole equipment, a callus on sole automatic feed mechanism of callus on sole equipment is related to.

Background

With the increasing dependence on computer systems, the market demands on computing power and data storage capacity of computer systems are increasing, and electronic products, including desktop computers and servers, which are used to protect advanced electronic products, are put into boxes.

The server case is generally made of sheet metal materials in a sheet mode to form a whole shell, wherein necessary elements of the server such as a hard disk, a mainboard and a display card are fixed in the case, and then supporting foot pads are arranged on the bottom face of the case to provide a better placing effect for the server.

The foot pad of the traditional case is assembled manually, and the foot pad is not firmly assembled and the overall processing efficiency is low due to the operation mode of manual assembly; therefore, the assembly equipment capable of realizing automatic assembly of the foot pad appears in the industry at present, the automatic assembly work of the foot pad of the case can be realized, the machining efficiency is higher, the machined foot pad is assembled more firmly in place, however, the mode that the automatic assembly equipment of the foot pad is mostly manual feeding in the machining process is adopted, and the machining efficiency of the foot pad assembly cannot reach the maximization.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model discloses a following technical scheme:

the utility model provides a callus on sole automatic feed mechanism of callus on sole equipment, includes according to callus on the sole feeding direction of processing in proper order: a foot pad feeding mechanism and a foot pad transferring mechanism;

callus on sole feed mechanism includes: the flexible vibration material tray is used for placing the foot pad, and the Y-axis discharging modules are arranged on two sides of the flexible vibration material tray, and the other end of each Y-axis discharging module extends towards the direction of the foot pad transferring mechanism;

a group of X-axis discharging modules are mounted on the Y-axis discharging modules and span the upper end of the flexible vibration material tray; a group of material taking modules are arranged on the X-axis material discharging module;

callus on sole shifts mechanism includes: the material receiving device and four groups of material transferring rails are connected with the material receiving device;

wherein, the tail end position of four groups of material rails that shift is provided with two sets of callus on the sole and changes the material device, and a set of callus on the sole changes material device and two groups of material rails that shift and correspond the cooperation.

As a further aspect of the present invention: get the material module and include: the material taking fixing support plate and the material taking lifting support plate are fixedly arranged on the X-axis discharging module; the material taking lifting support plate is arranged on the material taking fixed support plate through the Z-axis material taking module;

the bottom end of the material taking fixing support plate is provided with two groups of material taking seat plates, each material taking seat plate is provided with two groups of material taking slide rails which are arranged in parallel, a group of material taking supports are arranged on the material taking slide rails, and the material taking supports are provided with vacuum suction rods which vertically extend downwards;

the material taking seat plate is also provided with a pushing strip for driving the material taking bracket to work downwards along the material taking slide rail, and two sides of the working pushing strip are respectively provided with a pushing wheel which is abutted against the upper end of the material taking bracket; the rear end of the material taking seat plate is provided with a downlink rotating motor, and an output shaft of the downlink rotating motor penetrates through the material taking seat plate to be connected with the middle part of the working push bar.

As a further aspect of the present invention: the upper end of the flexible vibration material tray is provided with a group of material taking identification lenses which perform visual identification in the flexible vibration material tray from top to bottom.

As a further aspect of the present invention: callus on sole feed mechanism still includes: the visual detection group is arranged at the front side of the flexible vibration material tray and performs high-precision visual detection from bottom to top; the material taking support can be provided with a material taking rotating motor for driving the vacuum suction rod to rotate and adjust.

As a further aspect of the present invention: the rear end position of flexible vibration charging tray is provided with the feed fill that is used for realizing the feed for it, links to each other through the pay-off track between this feed fill and the flexible vibration charging tray.

As a further aspect of the present invention: receiving device includes: a material receiving cylinder; the moving direction of a piston rod of the material receiving cylinder is vertical to the conveying direction of the material transferring rail;

a piston rod of the material receiving cylinder is provided with a vertically upward connecting plate, the other end of the connecting plate is provided with a variable-pitch rod, and the variable-pitch rod is arranged at the upper end of the material receiving cylinder and is arranged in parallel with the material receiving cylinder;

receiving device still includes: the material receiving seats are arranged in parallel, material receiving grooves are formed in the material receiving seats, and the direction of the material receiving grooves is the same as the conveying direction of the material transferring rail; the material receiving seats close to the connecting plate are fixedly installed, the other material receiving seats are sleeved on the variable-pitch rods, the middle two material receiving seats are in sliding fit with the variable-pitch rods, and the material receiving seats at the tail ends are fixedly matched with the variable-pitch rods;

the lower ends of two adjacent material receiving seats are respectively provided with a group of limiting slats, a limiting sliding groove is arranged in each limiting slat, the lower ends of the material receiving seats are in sliding fit with the limiting sliding grooves, and position work is carried out through the limiting sliding grooves;

receiving device still includes: two material receiving transition plates are arranged, and each material receiving transition plate is provided with two material receiving grooves connected with the material transferring rail; the four receiving seats correspond to the four material passing grooves one by one, and when the receiving cylinder does not work, the receiving grooves of the four receiving seats are aligned with the four material passing grooves in a communicated manner;

receiving device still includes: the pushing plate is arranged at the rear end position of the receiving seat, and the pushing cylinder is used for driving the pushing plate to work towards one side of the transferring rail;

the push plate is provided with four push rods extending forwards, the push cylinder drives the four push rods on the push plate to be respectively inserted into the material receiving grooves of the four material receiving seats when working, and the foot pad is pushed out from the material receiving grooves to enter the material transferring rail through the material receiving grooves.

As a further aspect of the present invention: callus on sole commentaries on classics material device includes: a group of material transferring Y-axis modules crossing the upper end of the material transferring rail; a material transferring rack is arranged on the material transferring Y-axis module, and a material transferring lifting cylinder working vertically downwards is arranged on the material transferring rack;

install a upset motor on changeing the material lift cylinder, install a set of commentaries on classics material pole that outwards extends on this upset motor's the output shaft, be provided with two sets of commentaries on classics materials on changeing the material pole and inhale the pole.

As a further aspect of the present invention: the transfer material rail includes: the conveying belt set is started by a motor, two sides of the upper end of the conveying belt set are respectively provided with a limiting plate arranged along the length direction of the conveying belt set, and a feeding rail groove for feeding the foot pads is formed in a gap between the two limiting plates;

a group of material blocking seats are arranged at the tail ends of the feeding rail grooves, the foot pads are fed in through the feeding rail grooves, and the material blocking seats block the foot pads to be taken away when the foot pad transferring device works;

and a group of limiting devices with induction functions are arranged at the middle and rear sections of the feeding rail groove.

The utility model has the advantages that: realize the automatic material loading work of callus on the sole product, realize the turn-over of callus on the sole, inhale and angle fine setting work by callus on the sole feed mechanism in the in-process of processing, the slope upset (subsequent assembly processing of being convenient for) of rethread callus on the sole transfer mechanism realization callus on the sole is seen off the callus on the sole and is accomplished whole automatic feed flow, and processing degree of automation is high, and the precision of callus on the sole material loading is higher for the processingquality of follow-up assembly processing is higher.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a schematic structural view of the material taking module of the present invention.

Fig. 3 is a schematic view of another structure of the material taking module of the present invention.

Fig. 4 is a schematic structural view of the material receiving device of the present invention.

Fig. 5 is another schematic structural diagram of the receiving device of the present invention.

Fig. 6 is a schematic structural diagram of the middle transfer material rail of the present invention.

FIG. 7 is the structure schematic diagram of the material transferring device for the middle foot pad of the utility model

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it should be understood that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments, and it should be understood that the present application is not limited to the example embodiments disclosed and described herein. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as fixed or detachable connections or as an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

The utility model provides a please refer to and draw together 1 ~ 7, the embodiment of the utility model provides an in, a callus on sole automatic feed mechanism of callus on sole equipment includes according to callus on sole feeding direction of processing in proper order: a foot pad feeding mechanism 1 and a foot pad transferring mechanism 2;

callus on sole feed mechanism 1 includes: the device comprises a flexible vibration material tray 12 for placing a foot pad and a group of Y-axis discharging modules 11 arranged at two sides of the flexible vibration material tray, wherein the other end of each Y-axis discharging module 11 extends towards the direction of the foot pad transfer mechanism 2;

a group of X-axis discharging modules 16 are arranged on the Y-axis discharging module 11, and the X-axis discharging modules 16 cross over the upper end of the flexible vibration material tray 12; the X-axis discharging module 16 is provided with a group of material taking modules 14;

the foot pad transfer mechanism 2 includes: the material receiving device 21 and four groups of material transferring rails 22 connected with the material receiving device 21;

in order to realize the dislocation matching, two groups of the four groups of the transferring material rails 22 are in long rail structures, and two groups are in short rail structures; and the tail ends of the two long rail structure transferring material rails 22 and the two short rail structure transferring material rails 22 are respectively provided with a group of foot pad transferring devices 23.

When the flexible vibration material taking device works, the Y-axis discharging module 11 and the X-axis discharging module 16 are matched to drive the material taking module 14 to take materials on the flexible vibration material tray 12; then the foot pad is sent into a foot pad transfer mechanism 2; before material taking, the flexible vibration material tray 12 can continuously work to turn over the internal foot pads, and a group of material taking identification lenses 13 for performing visual identification in the flexible vibration material tray 12 from top to bottom are arranged at the upper end of the flexible vibration material tray 12; the foot pad is correctly taken by matching the flexible vibration material disc 12, the taking identification lens 13 and the taking module 14.

After four foot pads are sent into receiving device 21 at foot pad feed mechanism 1, send four foot pads into each transfer material rail 22 respectively through receiving device 21, change material device 23 through the foot pad at last and send out two liang of foot pads to back end processing equipment.

Further, the material taking module 14 includes: a material taking fixing support plate 141 and a material taking lifting support plate 143 which are fixedly arranged on the X-axis material discharging module 16; the material taking fixing support plate 141 is provided with a group of Z-axis material taking modules 14, and the material taking lifting support plate 143 is installed on the material taking fixing support plate 141 through the Z-axis material taking modules 14;

the bottom end of the material taking fixing support plate 141 is provided with two groups of material taking seat plates 146, each material taking seat plate 146 is provided with two groups of material taking slide rails 148 which are arranged in parallel, a group of material taking brackets 149 are arranged on the material taking slide rails 148, and the material taking brackets 149 are provided with vacuum suction rods 144 which vertically extend downwards;

the material taking seat plate 146 is further provided with a pushing strip 145 for driving the material taking bracket 149 to work downwards along the material taking slide rail 148, two sides of the working pushing strip 145 are respectively provided with a pushing wheel 147, and the pushing wheels 147 are abutted against the upper end of the material taking bracket 149; the rear end of the material taking seat plate 146 is provided with a downward rotating motor, and an output shaft of the downward rotating motor penetrates through the material taking seat plate 146 to be connected with the middle part of the working push bar 145; the downward rotating motor drives the working pushing bar 145 to swing to one side, so that the pushing wheel 147 on the side pushes the material taking bracket 149 on the side downwards along the material taking slide rail 148, and the vacuum suction rod 144 realizes material taking.

In order to ensure that the vacuum suction rod 144 of the material taking module 14 sucks up the foot pad, the angle of the foot pad is the same as the angle required by processing (the head and the tail of the foot pad need to be on the same axis with the mounting direction);

a group of visual detection groups 17 positioned at the front side of the flexible vibration material tray 12 (close to one side of the foot pad transfer mechanism 2) can be arranged, and the visual detection groups 17 perform high-precision visual detection from bottom to top; moreover, the material taking bracket 149 can be provided with a material taking rotating motor 140 for driving the vacuum suction rod 144 to rotate and adjust; in the feeding process, the vacuum suction rod 144 of the material taking module 14 enters the visual range of the visual detection group 17 one by one, high-precision visual detection is performed through the vacuum suction rod 144, and when the foot pad has an incorrect angle, the material taking rotating motor 140 drives the vacuum suction rod 144 to rotate and adjust, so that the angle of the foot pad is ensured to be correct, and the processing precision is improved.

In the processing process, in order to ensure that the normal processing action of the equipment cannot be influenced when the foot pads are loaded, a feeding hopper 15 for feeding the foot pads is arranged at the rear end position (far away from one side of the foot pad transfer mechanism 2) of the flexible vibration material disc 12, the feeding hopper 15 is connected with the flexible vibration material disc 12 through a feeding track, the foot pads are manually fed into the flexible vibration material disc 12 from the feeding hopper 15, and the feeding of the foot pads is realized on the premise of not influencing the processing action of the equipment; and one section of the feeding track between the feeding hopper 15 and the flexible vibration material tray 12 adopts a vibration track to realize feeding.

Further, the receiving device 21 includes: a material receiving cylinder 210; the moving direction of the piston rod of the material receiving cylinder 210 is vertical to the conveying direction of the material transferring rail 22;

a connecting plate 217 which is vertically upward is arranged on a piston rod of the material receiving cylinder 210, a variable-pitch rod 2111 is arranged at the other end of the connecting plate 217, and the variable-pitch rod 2111 is arranged at the upper end of the material receiving cylinder 210 and is arranged in parallel with the material receiving cylinder 210;

the receiving device 21 further includes: the material receiving seats 211 are arranged in parallel, material receiving grooves 218 are arranged on the material receiving seats 211, and the orientation of the material receiving grooves 218 is the same as the conveying direction of the transfer material rail 22; the material receiving seats 211 close to the connecting plate 217 are fixedly arranged, the other material receiving seats 211 are sleeved on the variable-pitch rods 2111, the two material receiving seats 211 in the middle are in sliding fit with the variable-pitch rods 2111, and the material receiving seat 211 at the tail end is fixedly matched with the variable-pitch rods 2111; the material receiving cylinder 210 drives the variable-pitch rod 2111 to move to one side, so that the material receiving seats 211 arranged on the variable-pitch rod 2111 are close to one side, and the effect that all four groups of material receiving seats 211 are close to one side is achieved;

in order to ensure that the two material receiving seats 211 in the middle can be smoothly reset to fixed positions, a group of limiting slats 219 are arranged at the lower ends of the two adjacent material receiving seats 211 (namely, the group of fixed material receiving seats 211 corresponds to the group of movable material receiving seats 211), a limiting chute is arranged in each limiting slat 219, the lower end of each material receiving seat 211 is in sliding fit with the corresponding limiting chute (the lower end of each material receiving seat 211 can be matched with the corresponding limiting chute by mounting a screw assembly in a penetrating manner), and the position work is carried out through the corresponding limiting chute;

the receiving device 21 further includes: two material receiving transition plates 213, wherein each material receiving transition plate 213 is provided with two material receiving grooves 214 connected with the material transferring rail 22; the four receiving seats 211 correspond to the four material passing grooves 214 one by one, and when the receiving cylinder 210 does not work, the receiving grooves 218 of the four receiving seats 211 are communicated with the four material passing grooves 214 one by one and aligned with each other;

the receiving device 21 further includes: a material pushing plate 216 disposed at the rear end position (the end far away from the transferring rail 22) of the material receiving seat 211 and a material pushing cylinder 212 for driving the material pushing plate 216 to work toward one side of the transferring rail 22;

four push rods 215 extending forwards are arranged on the material pushing plate 216, when the material receiving device 21 works on the material pushing plate 216, the material receiving cylinder 210 is driven to work to gather four groups of material receiving seats 211 together (corresponding to the positions of four vacuum suction rods 144 in the material taking module 14), after discharging is completed, the material receiving cylinder 210 is reset to enable each material receiving seat 211 to be restored to a preset position, then the material pushing cylinder 212 works to drive the four push rods 215 of the material pushing plate 216 to be respectively inserted into material receiving grooves 218 of the four material receiving seats 211, and foot pads are pushed out of the material receiving grooves 218 to enter the material transferring rail 22 through the material receiving grooves 214.

Further, the transfer rail 22 includes: a group of conveying belt sets 221 started by a motor, wherein two sides of the upper end of each conveying belt set 221 are respectively provided with a limit plate 222 arranged along the length direction of the conveying belt set, and a group of feeding rail grooves 223 for feeding foot pads are formed in a gap between the two limit plates 222;

a group of material blocking seats 225 are arranged at the tail ends of the feeding rail grooves 223, the foot pads are fed in through the feeding rail grooves 223 and blocked by the material blocking seats 225 to wait for the foot pad transferring device 23 to work and take the foot pads away;

and in order to avoid the situation that the position of the foot pad is deviated due to the stacking in the position of the material blocking seat 225, a group of limiting devices 224 with an induction function are arranged at the middle and rear sections of the feeding rail groove 223, and when the foot pad on the material blocking seat 225 is not taken away, the limiting devices 224 work to block the subsequent foot pad.

Further, callus on sole commentaries on classics material device 23 includes: a group of material transferring Y-axis modules 231 crossing the upper end of the material transferring rail 22, wherein one end of the material transferring Y-axis module 231 extends towards the rear section processing equipment; a material transferring rack 232 is arranged on the material transferring Y-axis module 231, and a material transferring lifting cylinder 234 working vertically and downwards is arranged on the material transferring rack 232;

a turning motor 233 is arranged on the material transferring lifting cylinder 234, a group of material transferring rods 235 extending towards the rear section processing equipment is arranged on an output shaft of the turning motor 233, and two groups of material transferring suction rods 236 are arranged on the material transferring rods 235;

when the material transferring device works, the material transferring lifting cylinder 234 drives the material transferring rod 235 to descend, the foot pad in the material transferring rail 22 is sucked up through the material transferring suction rod 236, then the material transferring lifting cylinder 234 is reset, and the material transferring rod 235 is driven to rotate by the overturning motor 233, so that the foot pad is obliquely arranged at an angle of 45 degrees (determined according to actual safety requirements); finally, the material transferring Y-axis module 231 drives the material transferring rod 235 to move to the rear-end processing equipment for material transferring.

It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element described by the phrase "comprising a. -" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The utility model provides a callus on sole automatic feed mechanism of callus on sole equipment which characterized in that includes according to callus on sole feeding direction of processing in proper order: a foot pad feeding mechanism and a foot pad transferring mechanism;

a group of X-axis discharging modules are mounted on the Y-axis discharging module and span across the upper end of the flexible vibration material tray; a group of material taking modules are arranged on the X-axis material discharging module;

callus on sole shifts mechanism includes: the material receiving device and four groups of material transferring rails connected with the material receiving device;

2. The automatic foot pad feeding mechanism of foot pad assembling equipment according to claim 1, wherein the material taking module comprises: the material taking fixing support plate and the material taking lifting support plate are fixedly arranged on the X-axis discharging module; the material taking lifting support plate is arranged on the material taking fixed support plate through the Z-axis material taking module;

3. The automatic foot pad feeding mechanism of the foot pad assembling device according to claim 2, wherein a group of material taking and identifying lenses for performing visual identification on the flexible vibration material tray from top to bottom is arranged at the upper end of the flexible vibration material tray.

4. The automatic foot pad feeding mechanism of the foot pad assembling equipment according to claim 2, wherein the foot pad feeding mechanism further comprises: the visual detection group is arranged at the front side of the flexible vibration material tray and performs high-precision visual detection from bottom to top; the material taking support can be provided with a material taking rotating motor for driving the vacuum suction rod to rotate and adjust.

5. The automatic foot pad feeding mechanism of the foot pad assembling equipment according to claim 2, wherein a feeding hopper for feeding the flexible vibrating material tray is arranged at the rear end of the flexible vibrating material tray, and the feeding hopper is connected with the flexible vibrating material tray through a feeding rail.

6. The automatic foot pad feeding mechanism of the foot pad assembling equipment according to claim 1, wherein the material receiving device comprises: a material receiving cylinder; the moving direction of a piston rod of the material receiving cylinder is vertical to the conveying direction of the material transferring rail;

receiving device still includes: two material receiving transition plates are arranged, and two material receiving grooves connected with the material transferring rail are arranged on each material receiving transition plate; the four receiving seats correspond to the four material passing grooves one by one, and when the receiving cylinder does not work, the receiving grooves of the four receiving seats are aligned with the four material passing grooves in a communicated manner;

7. The automatic foot pad feeding mechanism of the foot pad assembling equipment according to claim 1, wherein the foot pad transferring device comprises: a group of material transferring Y-axis modules crossing the upper end of the material transferring rail; a material transferring rack is arranged on the material transferring Y-axis module, and a material transferring lifting cylinder working vertically downwards is arranged on the material transferring rack;

8. The automatic foot pad feeding mechanism of the foot pad assembling equipment according to claim 1, wherein the transferring track comprises: the conveying belt set is started by a motor, two sides of the upper end of the conveying belt set are respectively provided with a limiting plate arranged along the length direction of the conveying belt set, and a feeding rail groove for feeding the foot pads is formed in a gap between the two limiting plates;

a group of limiting devices with induction functions are arranged at the middle and rear sections of the feeding rail groove.