Road belt cleaning device based on superhigh pressure water jet
Technical Field
The invention belongs to the technical field of road cleaning, and particularly relates to a road cleaning device based on ultrahigh-pressure water jet.
Background
Roads refer to highways, urban roads, and places where social motor vehicles are allowed to pass although in unit jurisdictions, including squares, public parks, and the like for public traffic. The utility model provides a road is the infrastructure that supplies various trackless vehicles and pedestrian to pass in the sense, and the CN216194384U of this publication discloses an integrated road belt cleaning device, belongs to road cleaning technical field, and this integrated road belt cleaning device includes road surface and sets up the belt cleaning device in the road surface inside, belt cleaning device is including setting up at the road surface internally mounted section of thick bamboo, the top fixedly connected with of installation section of thick bamboo is higher than the round platform on road surface, the inside of round platform is provided with the cavity, can draw water to belt cleaning device through the start-up water pump at first, and rivers flow into the high-pressure shower nozzle through main water pipe, branch water pipe and flexible hose, can wash the road surface through the high-pressure shower nozzle, and when washing, drive the high-pressure shower nozzle through elevating system and reciprocate, can effectually wash the dust on the road surface of different distances, this belt cleaning device structure is less to install in the road surface inside can not influence the normal traffic on the road surface, and on the other hand the device does not need a large amount of staff to operate, great reduction staff's amount of labour.
The problem in the prior art is that most of road cleaning devices are integrated with a transport vehicle in the road cleaning process, so that the cost is increased while the use efficiency of vehicles is wasted, and when the road is cleaned, the road surface can only be cleaned independently, and guardrails around the road can not be cleaned, so that the working efficiency of the cleaning devices is reduced.
Disclosure of Invention
According to the road cleaning device based on the ultra-high pressure water jet, the ultra-high pressure water jet is provided with the lifting block which is connected with the lifting block through the threaded engagement of the surface of the second screw rod and is limited by the second limiting rod, the lifting block can move up and down along the second screw rod, the effect of height adjustment according to the height of the guardrail around a road is achieved, water in the water storage tank can be conveyed into the water collecting plate through the connecting pipe by the pressurizing equipment, the water source can be sprayed onto the road ground through the first spray head, the spring ejector rod is used for propping up the connecting support to rotate around the fixed rod, the second spray head is vertically arranged to be parallel to the guardrail, the guardrail around the road is cleaned, the advantage of the use value of the cleaning device is improved, the problem that the use efficiency of a vehicle is increased while the use efficiency of the vehicle is wasted in the road cleaning process is solved, and the road can only be cleaned independently when the road is cleaned, and the work efficiency of cleaning the periphery of the road can not be reduced is solved.
The invention discloses a road cleaning device based on ultrahigh-pressure water jet, which comprises a frame shell, wherein a main beam is fixedly connected between the inner side surfaces of the frame shell, rotating shafts are rotatably arranged on the two sides of the inner surface of the frame shell, device mounting assemblies are arranged on the two ends of the rotating shafts, device supporting assemblies are arranged in the middle of the rotating shafts, mounting frames are arranged on the device supporting assemblies and the device mounting assemblies, a water storage tank is fixedly connected to the two sides of the inner surface of the frame shell and is positioned between the device supporting assemblies and the device mounting assemblies, two vertical supporting beams are fixedly connected to the middle of the inner surface of the mounting frames, a plurality of uniformly distributed threaded mounting holes are formed in the vertical supporting beams on the two sides, two side supporting beams are fixedly connected to the inner side surfaces of the vertical supporting beams on the two sides, the supporting beams are mounted on the device supporting assemblies in a matched mode through bolts, a multidirectional cleaning assembly is arranged on the two sides of the frame shell and is connected to the water storage tank through a connecting pipe, and a protection sheet metal is arranged on the outer side of the device supporting assembly and is fixedly connected to the lower surface of the main beam.
As the preferable mode of the invention, the device installation component comprises a first sliding rail, a first sliding block is arranged on two sides of the first sliding rail, a spring is fixedly connected between the first sliding blocks on two sides, and a transmission rod is rotatably arranged on two sides of the first sliding block on two sides.
As the preferable mode of the invention, the transmission rods at two sides are rotatably arranged on the first limiting rod, the first limiting rods at two sides are fixedly connected between the inner side surfaces of the clamping plates, the clamping plates at two sides and the mounting frame are matched, the lower ends of the clamping plates at two sides are fixedly connected with limiting sleeves, and the limiting sleeves at two sides are movably sleeved on the rotating shaft.
As the preferred device supporting component of the invention, the device supporting component comprises a first supporting rod and a second supporting rod, wherein the first supporting rod and the second supporting rod are respectively arranged in parallel, the two first supporting rods and the second supporting rod are crossed and arranged together, the crossing part is rotatably arranged together through a central shaft, a connecting rod is fixedly connected between the upper ends of the two first supporting rods and the second supporting rod, supporting lantern rings are rotatably arranged on the connecting rods at two sides, the upper ends of the supporting lantern rings at two sides are fixedly connected with mounting plates, screw holes are arranged at four corners of the upper surface of the mounting plates, and the screw holes are arranged on the supporting cross beams through bolts.
As the preferable multi-directional cleaning component of the invention comprises a first motor, wherein the first motor is fixedly connected to two sides of the upper surface of a main beam, bevel gears are fixedly sleeved on output shafts of the first motor on two sides, two bevel gears are connected to two sides of the bevel gears in a meshed manner through clamping teeth, the other two bevel gears are sleeved on one end of the inner side of a first screw rod, and the first screw rods on two sides are rotatably arranged on the inner wall of a frame shell.
As the preferable mode of the invention, the first screw rod at two sides is connected with a thread bush through thread engagement, one side of the thread bush is fixedly connected with a second sliding block, the second sliding blocks at two sides are arranged in a second sliding rail, the second sliding rail is fixedly connected with the inner wall of the frame shell, and the upper surfaces of the thread bush at two sides are fixedly connected with C-shaped mounting plates.
As the preferable mode of the invention, the upper surface of the C-shaped mounting plate is fixedly connected with a second motor, the outer side of the second motor is provided with a protective shell, the output shaft of the second motor is fixedly sleeved with a transmission gear, the other transmission gear is fixedly sleeved at the upper end of a rotating rod, the two transmission gears are meshed together through a latch, the lower end of the rotating rod is rotatably mounted on the front surface of the C-shaped mounting plate through a mounting sheet metal, and the lower end of the rotating rod is fixedly connected with a fixing bracket through a fixing seat.
As the preferable mode of the invention, the upper surface of the fixing support is fixedly connected with a third motor, the output shaft of the third motor is fixedly connected with a second screw rod, the second screw rod is connected with a lifting block through threaded engagement of the surface, two sides of the lifting block are movably provided with second limiting rods, the second limiting rods are fixedly connected between the inner side surfaces of the fixing support, one side of the lifting block is fixedly connected with a pressurizing device, and one side of the pressurizing device is fixedly connected with a water collecting plate.
As the preferable mode of the invention, the upper surface of the water collecting plate is provided with a plurality of evenly distributed grooves, a second spray head is rotatably arranged in each groove, a water pipe is connected below each second spray head, a plurality of evenly distributed first spray heads are arranged on the lower surface of the water collecting plate, a connecting bracket is fixedly connected with the upper surface of each second spray head, the connecting bracket is rotatably arranged on a fixing rod, two ends of the fixing rod are fixedly connected to one side surface of the water collecting plate through limiting metal plates, and a spring ejector rod is rotatably arranged between the connecting bracket and a supporting block.
Compared with the prior art, the invention has the following beneficial effects:
1. According to the invention, the first sliding blocks on two sides can be driven to move towards two sides of the first sliding rail along the first sliding rail through the supporting function of the spring, the transmission rods are rotatably arranged on the first sliding blocks on two sides, the other ends of the transmission rods are fixedly connected between the inner side surfaces of the clamping plates through the first limiting rods, the clamping plates on two sides are rotatably arranged on the rotating shaft, and the clamping plates on two sides can be driven to move towards two sides by taking the rotating shaft as the center, so that the mounting frame is fixed on the frame shell, and the whole cleaning device is better convenient to mount on the chassis of the transport vehicle.
2. According to the invention, the lower ends of the first support rod and the second support rod are rotatably arranged on the rotating shafts, the first support rod and the second support rod are crossed and arranged together, the crossed parts are rotatably arranged together through the central shaft, so that the two rotating shafts can be supported, the connecting rod is fixedly connected between the upper ends of the first support rod and the second support rod, the connecting rod is connected with the mounting plate through the support sleeve ring, the mounting plate is matched and arranged together through the threaded holes and the threaded mounting holes on the vertical support beams, the effect of fixedly mounting the mounting frame is achieved, and the mounting steps are convenient, rapid and high in stability.
3. According to the invention, the second screw rod is driven to rotate by the third motor, the second screw rod is connected with the lifting block through the threaded engagement of the surface, the lifting block limits the second screw rod through the second limiting rod, so that the lifting block can move up and down along the second screw rod, the effect of adjusting the height of the guardrail around a road is achieved, water in the water storage tank can be conveyed into the water collecting plate through the connecting pipe by the pressurizing equipment, a water source can be sprayed onto the ground of the road through the first spray head, and then the spring ejector rod props against the connecting support to rotate around the fixed rod, so that the second spray head is vertically arranged in parallel with the guardrail, the guardrail around the road is cleaned, and the use value of the cleaning device is improved.
4. According to the invention, the second motor drives the transmission gear to rotate, the other transmission gear is fixedly sleeved at the upper end of the rotary rod, the two transmission gears are meshed and connected together through the latch, the rotary rod is fixedly connected to the front surface of the C-shaped mounting plate through the mounting sheet metal, the rotary rod can be driven to rotate, the lower end of the rotary rod is fixedly connected with the fixing support through the fixing seat, the fixing support can be driven to rotate by taking the rotary rod as the center, the direction adjustment effect of the fixing support is achieved, and the rotary rod is better suitable for sector adjustment of the ground.
Drawings
FIG. 1 is a schematic perspective view of an overall top view structure provided by an embodiment of the present invention;
FIG. 2 is a schematic perspective view of the overall bottom view provided by an embodiment of the present invention;
FIG. 3 is a schematic perspective view of a partial explosion structure provided by an embodiment of the present invention;
FIG. 4 is a schematic perspective view of a device mounting assembly provided by an embodiment of the present invention;
FIG. 5 is a schematic perspective view of a device support assembly according to an embodiment of the present invention;
FIG. 6 is a schematic perspective view of the overall structure of a multi-directional cleaning assembly provided by an embodiment of the present invention;
FIG. 7 is a schematic perspective view of a partial structure of a multi-directional cleaning assembly provided by an embodiment of the present invention;
fig. 8 is a schematic perspective view of a cross-sectional structure of a water collecting plate according to an embodiment of the present invention;
Fig. 9 is an enlarged schematic perspective view of the structure a in fig. 7 provided by an embodiment of the present invention.
In the figure, a frame shell, 2, a main beam, 3, a water storage tank, 4, a vertical supporting beam, 5, a supporting beam, 6, a device supporting component, 7, a bolt, 8, a device installation component, 9, a mounting rack, 10, a multidirectional cleaning component, 11, a connecting pipe, 12, a protection metal plate, 13, a rotating shaft, 601, a first supporting rod, 602, a second supporting rod, 603, a central shaft, 604, a connecting rod, 605, a supporting collar, 606, a mounting plate, 607, a threaded hole, 801, a limiting sleeve, 802, a clamping plate, 803, a first limiting rod, 804, a transmission rod, 805, a first sliding rail, 806, a first sliding block, 807, a spring, 101, a first motor, 102, a bevel gear, 103, a first screw rod, 104, a threaded sleeve, 105, a second sliding block, 106, a second sliding rail, 107, a C-shaped mounting plate, 108, a protection shell, 109, a second motor, 110, a transmission gear, 111, a rotating rod, 112, a mounting metal plate, 113, a fixing seat, 114, a fixing bracket, 115, a third motor, 116, a second screw rod, 117, a lifting block, a second limiting rod, 118, a lifting block, a pressing block, a 17, a spring, a supporting block, a water collecting block, a 121, a water nozzle, a supporting block, a support, a water-collecting block, a supporting block, a 121, a spray head, a water pipe, a supporting block, a spray head, a supporting block, a spray head, a water supply, a spray head, a water supply, a spray head, and a spray head, a spray head and a water supply.
Detailed Description
For a further understanding of the present invention, its objects, features and advantages, reference should be made to the following examples which are illustrated in the accompanying drawings.
The structure of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1 to 9, the road cleaning device based on ultra-high pressure water jet provided by the embodiment of the invention comprises a frame shell 1, wherein a main beam 2 is fixedly connected between the inner side surfaces of the frame shell 1, two sides of the inner surfaces of the frame shell 1 are rotatably provided with rotating shafts 13, two ends of each rotating shaft 13 are provided with device mounting assemblies 8, the middle parts of each rotating shaft 13 are provided with device supporting assemblies 6, the device supporting assemblies 6 and the device mounting assemblies 8 are provided with mounting frames 9, two water storage tanks 3 are fixedly connected to the inner surfaces of the frame shell 1, the water storage tanks 3 are positioned between the device supporting assemblies 6 and the device mounting assemblies 8, two vertical supporting beams 4 are fixedly connected to the middle parts of the inner surfaces of the mounting frames 9, the two vertical supporting beams 4 are provided with a plurality of uniformly distributed threaded mounting holes, the inner side surfaces of the two vertical supporting beams 4 are fixedly connected with two side supporting beams 5, the two side supporting beams 5 are cooperatively mounted on the device supporting assemblies 6 through bolts 7, the two sides of the frame shell 1 are provided with multi-directional cleaning assemblies 10, the multi-directional cleaning assemblies 10 are connected to the water storage tanks 3 through connecting pipes 11, the outer sides of the connecting pipes 11 are also provided with protection sheet metal plates 12, and the protection sheet metal 12 are fixedly connected to the lower surface of the main beam 2.
The device mounting assembly 8 comprises a first slide rail 805, a first slide block 806 is arranged on two sides of the first slide rail 805, a spring 807 is fixedly connected between the first slide blocks 806 on two sides, a transmission rod 804 is rotatably arranged on two sides of the first slide block 806 on two sides, the transmission rod 804 on two sides is rotatably arranged on the first limit rod 803, the first limit rod 803 on two sides is fixedly connected between the inner side surfaces of the clamping plates 802, the clamping plates 802 on two sides and the mounting frame 9 are matched, the lower ends of the clamping plates 802 on two sides are fixedly connected with limit sleeves 801, and the limit sleeves 801 on two sides are movably sleeved on the rotating shaft 13;
the spring 807 plays a supporting role and drives the first slide blocks 806 on two sides to move along the first slide rail 805 towards two sides of the first slide rail 805, the first slide blocks 806 on two sides are rotatably provided with the transmission rods 804, the other ends of the transmission rods 804 are fixedly connected between the inner side surfaces of the clamping plates 802 through the first limit rods 803, the clamping plates 802 on two sides are rotatably arranged on the rotating shaft 13, and the clamping plates 802 on two sides can be driven to move towards two sides by taking the rotating shaft 13 as the center, so that the mounting frame 9 is fixed on the frame shell 1, and the whole cleaning device is better convenient to install on the chassis of the transport vehicle.
The device support assembly 6 comprises a first support rod 601 and a second support rod 602, wherein the first support rod 601 and the second support rod 602 are arranged in parallel, the first support rod 601 and the second support rod 602 are arranged in a crossing mode and are rotatably arranged at the crossing position through a central shaft 603, a connecting rod 604 is fixedly connected between the upper ends of the first support rod 601 and the second support rod 602, support lantern rings 605 are rotatably arranged on the connecting rods 604 at the two sides, mounting plates 606 are fixedly connected to the upper ends of the support lantern rings 605 at the two sides, threaded holes 607 are formed in four corners of the upper surface of the mounting plates 606, and the threaded holes 607 are arranged on the support cross beams 5 through bolts 7;
The lower ends of the first support rod 601 and the second support rod 602 are rotatably arranged on the rotating shaft 13, the first support rod 601 and the second support rod 602 are arranged in a crossed mode, the crossed portions are rotatably arranged through the central shaft 603, the two rotating shafts 13 can be supported, a connecting rod 604 is fixedly connected between the upper ends of the first support rod 601 and the second support rod 602, the connecting rod 604 is connected with a mounting plate 606 through a supporting collar 605, the mounting plate 606 is matched with a threaded mounting hole in the vertical support beam 4 through a threaded hole 607, the effect of fixedly mounting the mounting frame 9 is achieved, and the mounting step is convenient, quick and high in stability.
The multidirectional cleaning assembly 10 comprises a first motor 101, wherein the first motor 101 is fixedly connected to two sides of the upper surface of a main beam 2, bevel gears 102 are fixedly sleeved on output shafts of the first motors 101 on two sides, two bevel gears 102 are connected to two sides of the bevel gears 102 through latch meshing, the other two bevel gears 102 are sleeved on one end of the inner side of a first screw rod 103, the first screw rod 103 on two sides is rotatably installed on the inner wall of a frame shell 1, screw sleeves 104 are connected to the first screw rods 103 on two sides through screw meshing, a second sliding block 105 is fixedly connected to one side of each screw sleeve 104, the second sliding block 105 is installed in a second sliding rail 106, the second sliding rail 106 is fixedly connected to the inner wall of the frame shell 1, and a C-shaped mounting plate 107 is fixedly connected to the upper surface of each screw sleeve 104;
The first motor 101 drives the bevel gear 102 to rotate, the bevel gear 102 is connected with the bevel gears 102 on the other two first screw rods 103 through latch meshing, the first screw rods 103 on two sides are connected with the threaded sleeve 104 through surface threaded meshing, the threaded sleeve 104 can move inwards or outwards simultaneously along the first screw rods 103 through limiting of the second sliding block 105 and the second sliding rail 106, and the effect of adjusting the width of a cleaning road can be achieved.
The upper surface of the C-shaped mounting plate 107 is fixedly connected with a second motor 109, the outer side of the second motor 109 is provided with a protective shell 109, the output shaft of the second motor 109 is fixedly sleeved with a transmission gear 110, the other transmission gear 110 is fixedly sleeved at the upper end of a rotating rod 111, the two transmission gears 110 are meshed together through a latch, the lower end of the rotating rod 111 is rotatably mounted on the front surface of the C-shaped mounting plate 107 through a mounting sheet metal 112, and the lower end of the rotating rod 111 is fixedly connected with a fixing bracket 114 through a fixing seat 113;
the second motor 109 drives the transmission gear 110 to rotate, the other transmission gear 110 is fixedly sleeved at the upper end of the rotary rod 111, the two transmission gears 110 are connected together through latch meshing, the rotary rod 111 is fixedly connected to the front surface of the C-shaped mounting plate 107 through the mounting metal plate 112, the rotary rod 111 can be driven to rotate, the lower end of the rotary rod 111 is fixedly connected with the fixing support 114 through the fixing seat 113, the fixing support 114 can be driven to rotate by taking the rotary rod 111 as the center, the effect of adjusting the direction of the fixing support 114 is achieved, and the rotary rod is better suitable for fan-shaped adjustment of the ground.
The upper surface of the fixed bracket 114 is fixedly connected with a third motor 115, an output shaft of the third motor 115 is fixedly connected with a second screw rod 116, the second screw rod 116 is connected with a lifting block 118 through threaded engagement on the surface, two sides of the lifting block 118 are movably provided with a second limiting rod 117, the second limiting rod 117 is fixedly connected between the inner side surfaces of the fixed bracket 114, one side of the lifting block 118 is fixedly connected with a pressurizing device 119, one side of the pressurizing device 119 is fixedly connected with a water collecting plate 120, the upper surface of the water collecting plate 120 is provided with a plurality of evenly distributed grooves 122, a second spray head 123 is rotatably arranged in the grooves 122, a water pipe 125 is connected below each second spray head 123, the lower surface of the water collecting plate 120 is provided with a plurality of evenly distributed first spray heads 121, the upper surface of each second spray head 123 is fixedly connected with a connecting bracket 124, the connecting bracket 124 is rotatably arranged on the fixed rod 126, two ends of the fixed rod 126 are fixedly connected with one side surface of the water collecting plate 120 through limiting metal plates 127, and a spring 128 is rotatably arranged between the connecting bracket 124 and the supporting block 129;
The second screw rod 116 is driven to rotate through the third motor 115, the second screw rod 116 is connected with the lifting block 118 through the threaded engagement of the surface, the lifting block 118 limits the second screw rod through the second limiting rod 117, the lifting block 118 can move up and down along the second screw rod 116, the effect of height adjustment according to the height of the guardrail around a road is achieved, water in the water storage tank 3 can be conveyed into the water collecting plate 120 through the connecting pipe 11 by the pressurizing device 119, a water source can be sprayed onto the road ground through the first spray head 121, the spring ejector rod 128 is used for propping the connecting support 124 to rotate by taking the fixing rod 126 as the center, the second spray head 123 can be vertically arranged to be parallel to the guardrail, and therefore the guardrail around the road is cleaned, and the use value of the cleaning device is improved.
The working principle of the invention is as follows:
when in use, the invention can drive the first slide blocks 806 on two sides to move along the first slide rail 805 towards two sides of the first slide rail 805 by the supporting function of the springs 807, the first slide blocks 806 on two sides are rotatably provided with the transmission rods 804, the other ends of the transmission rods 804 are fixedly connected between the inner side surfaces of the clamping plates 802 by the first limiting rods 803, the two side clamping plates 802 are rotatably arranged on the rotating shafts 13, the two side clamping plates 802 can be driven to move towards two sides by taking the rotating shafts 13 as the center, thereby fixing the mounting frame 9 on the frame shell 1, being better convenient for mounting the whole cleaning device on the chassis of a transport vehicle, being rotatably arranged on the rotating shafts 13 by the lower ends of the first supporting rods 601 and the second supporting rods 602, being arranged together in a crossing way and being rotatably arranged together by the central shafts 603 at the crossing part, being capable of supporting the two rotating shafts 13, a connecting rod 604 is fixedly connected between the upper ends of the first support rod 601 and the second support rod 602, the connecting rod 604 is connected with a mounting plate 606 through a support collar 605, the mounting plate 606 is matched with a threaded mounting hole on the vertical support beam 4 through a threaded hole 607 to achieve the effect of fixedly mounting the mounting frame 9, the mounting step is convenient and quick, meanwhile, the stability is high, the second screw 116 is driven to rotate through the third motor 115, the second screw 116 is connected with a lifting block 118 through the threaded engagement of the surface, the lifting block 118 limits the lifting block through the second limiting rod 117, the lifting block 118 can move up and down along the second screw 116, the effect of height adjustment according to the height of guardrails around a road is achieved, water in the water storage tank 3 can be conveyed into the water collection plate 120 through the connecting pipe 11 by the pressurizing equipment 119, the water source can be sprayed onto the road surface through the first spray head 121, the connecting support 124 is supported by the spring ejector rod 128 to rotate by taking the fixing rod 126 as the center, the second spray head 123 is vertically arranged and parallel to the guardrail, thereby the guardrail on the periphery of the road is cleaned, the use value of the cleaning device is improved, the second motor 109 drives the transmission gear 110 to rotate, the other transmission gear 110 is fixedly sleeved at the upper end of the rotating rod 111, the two transmission gears 110 are connected together through the engagement of the clamping teeth, the rotating rod 111 is fixedly connected to the front surface of the C-shaped mounting plate 107 through the mounting sheet metal 112, the rotating rod 111 can be driven to rotate, the fixing support 114 is driven to rotate by taking the rotating rod 111 as the center through the fixing seat 113, the direction adjustment effect on the fixing support 114 is achieved, the cleaning device is better suitable for sector adjustment on the ground, the first motor 101 drives the bevel gear 102 to rotate, the bevel gear 102 on the other two first lead screws 103 are fixedly sleeved on the upper end of the rotating rod 111 through the clamping teeth, the two transmission gears 103 are connected with the threaded sleeves 104 through the threaded sleeves on the surfaces, and the threaded sleeves 104 can be simultaneously moved to the outer sides of the threaded sleeves 104 through the threaded sleeves 104, and the threaded sleeves of the threaded sleeves 104 can be simultaneously moved to the inner sides of the threaded sleeves 106 or the threaded sleeves can be adjusted along the threaded sleeves.
It is noted that relational terms such as first and second, and the like are 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. Moreover, 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.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.