阅读说明：本技术 一种载货卡车贮油储备车箱 (Oil storage carriage of cargo truck ) 是由 戴泽鹏 于 2021-10-25 设计创作，主要内容包括：本发明涉及储备油箱领域,尤其涉及一种载货卡车贮油储备车箱,包括有底板、安装外壳、减震组件、左右缓冲组件等；底板顶部固定安装有安装外壳,安装外壳上设置有减震组件,左右缓冲组件滑动式连接于安装外壳上。通过支撑弹簧的作用,能够对减震滑板及其上装置进行缓冲,避免减震滑板及其上装置上下剧烈抖动,同时扭力弹簧能够对开槽摆杆造成阻力,避免贮油箱向上运动过多,防止贮油箱与安装外壳撞击。(The invention relates to the field of reserve fuel tanks, in particular to a fuel storage reserve carriage of a cargo truck, which comprises a bottom plate, a mounting shell, a damping component, a left buffer component, a right buffer component and the like; bottom plate top fixed mounting has the installation shell, is provided with damper assembly on the installation shell, controls buffer assembly sliding type and connects on the installation shell. Through supporting spring's effect, can cushion shock attenuation slide and device on it, avoid shock attenuation slide and device on it to shake violently from top to bottom, torsion spring can cause the resistance to the slotted pendulum rod simultaneously, avoids the oil storage tank upward movement too much, prevents oil storage tank and installation shell striking.)

1. The utility model provides a cargo truck stores oil deposit railway carriage, including bottom plate, installation shell, damper assembly, control buffering subassembly and oil transportation subassembly, its characterized in that, damper assembly is including four corner posts, supporting spring, shock attenuation slide, sliding block, oil storage tank, fluting pendulum rod and torsion spring:

the mounting shell is fixedly mounted at the top of the bottom plate;

the damping component is arranged on the mounting shell;

the left and right buffer components are connected to the mounting shell in a sliding manner;

the oil transportation component is also arranged on the mounting shell;

the inner bottom surface of the mounting shell is welded with two pairs of four-corner columns;

the damping sliding plates are connected to the two pairs of four-corner columns in a sliding manner;

the damping sliding plate is fixedly connected with two pairs of supporting springs, one end of each supporting spring is fixedly connected with the mounting shell, and each supporting spring is used for buffering the oil storage tank and plays a role in reducing severe vibration of the oil tank;

the damping sliding plate is connected with two sliding blocks in a sliding manner;

the top surfaces of the two sliding blocks jointly support the oil storage tank, and the oil storage tank is used for storing diesel oil and has the function of supplying the diesel oil to the freight car oil tank;

the slotted oscillating bar is rotatably connected with the two sides in the installation shell and is in limit fit with the oil storage tank;

the torsion spring is fixedly connected to the slotted swing rod, one end of the torsion spring is connected with the mounting shell, and the torsion spring is used for causing resistance to the slotted swing rod and playing a role in preventing the oil storage tank from moving too much upwards.

2. The truck cargo storage tank as defined in claim 1, wherein the left and right buffering assemblies comprise two pairs of movable columns, a buffering plate and a buffering spring, the mounting housing is slidably connected with the two pairs of movable columns, the buffering plate is welded to one end of the two movable columns on the same side, one side of the buffering plate is connected with a pair of buffering springs, and one end of each buffering spring is fixedly connected with the mounting housing.

3. The truck cargo truck oil storage carriage according to claim 2, wherein the oil delivery assembly comprises an oil delivery pipe, a rotating rod, a blocking disk and a rotating gear, the oil delivery pipe is slidably connected to the mounting housing, the oil delivery pipe is connected to the oil storage tank, the rotating rod is rotatably connected to the oil delivery pipe, the blocking disk is arranged on the rotating rod, the blocking disk is located in the oil delivery pipe, and the rotating gear is fixedly connected to the rotating rod.

4. The truck oil storage carriage as claimed in claim 3, further comprising a clamping assembly, wherein the clamping assembly is disposed on the oil delivery pipe, the clamping assembly comprises a first mounting plate, a second mounting plate, a sliding rack, a pressing spring, a lifting groove block, a compression spring and a clamping rod, the first mounting plate is welded on the oil delivery pipe, the second mounting plate is also disposed on the oil delivery pipe, the first mounting plate and the second mounting plate are jointly slidably connected with the sliding rack, the sliding rack is meshed with the rotating gear, the four pressing springs are sleeved on the sliding rack, the sliding rack is in contact with one end of the pressing spring, the other ends of the two pressing springs are in contact with the first mounting plate, the other ends of the two pressing springs are in contact with the second mounting plate, the lifting groove block is connected to the first mounting plate in a lifting manner, the top surface of the lifting groove block is fixedly connected with the compression spring, and one end of the compression spring is connected with the first mounting plate, the lifting groove block is connected with a clamping rod in a sliding mode, and the clamping rod is connected with the sliding rack in a limiting mode.

5. The truck oil storage compartment as claimed in claim 4, further comprising a shifting assembly, wherein the shifting assembly is disposed on the bottom plate, the shifting assembly comprises a servo motor, a power shaft, a convex disc, a shifting rod and a lifting rod, the servo motor is fixedly mounted on the bottom plate, the power shaft is welded on the top end of an output shaft of the servo motor, the convex disc is welded on the top end of the power shaft, the shifting rod is slidably connected to the bottom plate, the shifting rod is in contact with the convex disc, the lifting rod is welded on one end of the shifting rod, and the clamping rod is slidably connected with the lifting rod.

6. The cargo truck oil storage reserve carriage as defined in claim 5, further comprising a pulling assembly, wherein the pulling assembly is slidably connected to the base plate, the pulling assembly comprises a sector gear, a pulling rack, a pull rod and a pushing spring, the sector gear is disposed on the power shaft, the pulling rack is slidably connected to the base plate, the pull rod is fixedly connected to the pulling rack, the pull rod is slidably connected to the mounting housing, the pull rod is in limit connection with the sliding rack, and the pushing spring is connected between the pull rod and the sliding rack.

7. The truck cargo tank according to claim 6 further comprising fixed slotted plates and communicating tubes, wherein three fixed slotted plates are disposed in the tank, and the communicating tubes are fixedly connected to the tank.

Technical Field

The invention relates to the field of reserve fuel tanks, in particular to a fuel storage reserve carriage of a freight truck.

Background

The oil tank is the container of dress fuel, is the special container of storage hydraulic oil or hydraulic fluid among the hydraulic system, and the oil tank can divide into open oil tank and closed oil tank two kinds, and the oil tank generally all has enough big volume, and the oil tank volume has decided the mileage of traveling, and is inequality according to the motorcycle type, and the capacity of freight train and car oil tank also can be different, and the additional range of having reequiped the auxiliary automobile oil tank in order to increase the vehicle of motorcycle type for some motorcycle types.

The existing oil tank of a large truck has small volume, the volume of the oil tank is 140 liters or less, and the large truck has large cargo capacity, so that the diesel oil consumption is large when the large truck runs at high speed, the endurance mileage is short, the oiling times are more, or the large truck can be used up in a short time after oiling once, and the condition of insufficient oil quantity is easy to frequently occur.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an oil storage and storage compartment of a truck, which can supplement diesel oil to a large truck oil tank, can absorb shock of the oil tank and can enable the endurance mileage of the truck to reach a longer distance, so as to solve the problems that the existing oil tank of the large truck has a smaller volume, is easy to frequently cause insufficient oil, has shorter endurance mileage and has more oil adding times in the background technology.

The technical scheme is as follows: the utility model provides a cargo truck stores oil deposit railway carriage, including bottom plate, installation shell, damper assembly, control buffering subassembly and oil transportation subassembly, its characterized in that, damper assembly is including four corner posts, supporting spring, shock attenuation slide, sliding block, oil storage tank, fluting pendulum rod and torsion spring:

the mounting shell is fixedly mounted at the top of the bottom plate;

the damping component is arranged on the mounting shell;

the left and right buffer components are connected to the mounting shell in a sliding manner;

the oil transportation component is also arranged on the mounting shell;

the inner bottom surface of the mounting shell is welded with two pairs of four-corner columns;

the damping sliding plates are connected to the two pairs of four-corner columns in a sliding manner;

the damping sliding plate is fixedly connected with two pairs of supporting springs, one end of each supporting spring is fixedly connected with the mounting shell, and each supporting spring is used for buffering the oil storage tank and plays a role in reducing severe vibration of the oil tank;

the damping sliding plate is connected with two sliding blocks in a sliding manner;

the top surfaces of the two sliding blocks jointly support the oil storage tank, and the oil storage tank is used for storing diesel oil and has the function of supplying the diesel oil to the freight car oil tank;

the slotted oscillating bar is rotatably connected with the two sides in the installation shell and is in limit fit with the oil storage tank;

the torsion spring is fixedly connected to the slotted swing rod, one end of the torsion spring is connected with the mounting shell, and the torsion spring is used for causing resistance to the slotted swing rod and playing a role in preventing the oil storage tank from moving too much upwards.

Preferably, the left and right buffering assemblies comprise movable columns, buffering plates and buffering springs, the mounting shell is connected with two pairs of movable columns in a sliding mode, the buffering plates are welded at one ends of the two movable columns on the same side, one side of each buffering plate is connected with one pair of buffering springs, and one end of each buffering spring is fixedly connected with the mounting shell.

Preferably, the oil transportation assembly comprises an oil transportation pipe, a rotating rod, a blocking disc and a rotating gear, the oil transportation pipe is connected to the mounting shell in a sliding mode and is connected with the oil storage tank, the rotating rod is connected to the oil transportation pipe in a rotating mode, the blocking disc is arranged on the rotating rod and is located in the oil transportation pipe, and the rotating gear is fixedly connected to the rotating rod.

Preferably, the oil pipe installation device further comprises a clamping assembly, the clamping assembly is arranged on the oil pipe, the clamping assembly comprises a first mounting plate, a second mounting plate, a sliding rack, an extrusion spring, a lifting groove block, a compression spring and a clamping rod, the first mounting plate is welded on the oil pipe, the second mounting plate is also arranged on the oil pipe, the first mounting plate and the second mounting plate are jointly connected with the sliding rack in a sliding mode, the sliding rack is meshed with a rotating gear, the four extrusion springs are sleeved on the sliding rack, the sliding rack is contacted with one end of the extrusion spring, the other ends of the two extrusion springs are contacted with the first mounting plate, the other ends of the two extrusion springs are contacted with the second mounting plate, the lifting groove block is connected to the first mounting plate in a lifting mode, the top surface of the lifting groove block is fixedly connected with the compression spring, one end of the compression spring is connected with the first mounting plate, and the clamping rod is connected to the lifting groove block in a sliding mode, the clamping rod is connected with the sliding rack in a limiting way.

As preferred, still including stirring the subassembly, be provided with on the bottom plate and stir the subassembly, stir the subassembly including servo motor, power shaft, flange, driving lever and lifting rod, fixed mounting has servo motor on the bottom plate, and the welding of servo motor output shaft top has the power shaft, and the welding of power shaft top has the flange, and driving lever sliding type connects on the bottom plate, driving lever and flange be in contact with each other, and the welding of driving lever one end has the lifting rod, and the kelly is connected with lifting rod sliding type.

Preferably, the device further comprises a pulling assembly, the bottom plate is connected with the pulling assembly in a sliding mode, the pulling assembly comprises a sector gear, a pulling rack, a pull rod and a pushing spring, the sector gear is arranged on a power shaft, the bottom plate is connected with the pulling rack in a sliding mode, the pulling rack is fixedly connected with the pull rod, the pull rod is connected with the installation shell in a sliding mode, the pull rod is connected with the sliding rack in a limiting mode, and the pushing spring is connected between the pull rod and the sliding rack.

Preferably, the oil storage tank also comprises fixed slotted plates and a communicating pipe, wherein three fixed slotted plates are arranged in the oil storage tank, and the communicating pipe is fixedly connected to the oil storage tank.

The invention has the beneficial effects that:

through supporting spring's effect, can cushion shock attenuation slide and device on it, avoid shock attenuation slide and device on it to shake violently from top to bottom, torsion spring can cause the resistance to the slotted pendulum rod simultaneously, avoids the oil storage tank upward movement too much, prevents oil storage tank and installation shell striking.

Through buffer spring's effect, cushion the buffer board, the buffer board blocks the oil storage tank, reduces the oil storage tank seesaw stroke, avoids the oil storage tank by the striking.

The sliding rack is clamped through the clamping rod, the sliding rack can be prevented from moving when the equipment is shaken left and right, the sliding rack can clamp the rotating gear, the blockage of the disk is avoided, the oil conveying pipe is opened by rotating, and diesel oil is prevented from flowing out from a gap between the blockage disk and the oil conveying pipe.

Rotate through blockking up the disc and no longer block defeated oil pipe, defeated oil pipe can carry the diesel oil to the freight train oil tank in, realizes supplementing the purpose of diesel oil to the freight train for freight train continuation of the journey mileage can reach farther.

Drawings

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

Fig. 2 is a schematic sectional perspective view of the present invention.

FIG. 3 is a schematic cross-sectional perspective view of the left and right cushion assemblies of the present invention.

Figure 4 is a schematic perspective view, partially in section, of a shock assembly according to the present invention.

Fig. 5 is a schematic view of a partially cut-away perspective structure of the present invention.

Fig. 6 is a partial perspective view of the clamping assembly of the present invention.

Fig. 7 is an enlarged schematic view of the structure of the present invention a.

Fig. 8 is a schematic separated perspective view of the oil transportation assembly of the present invention.

FIG. 9 is a schematic drawing showing a partial perspective view of the pulling assembly of the present invention.

Fig. 10 is a schematic partial perspective view of the toggle assembly of the present invention.

Description of reference numerals: 1_ base plate, 2_ mounting housing, 3_ damping member, 31_ four-corner post, 32_ supporting spring, 33_ damping slide plate, 34_ slide block, 35_ reservoir, 36_ slotted rocker bar, 37_ torsion spring, 4_ left and right damping member, 41_ movable post, 42_ damping plate, 43_ damping spring, 5_ oil delivery member, 51_ oil delivery tube, 52_ rotating rod, 53_ blocking disk, 54_ rotating gear, 6_ clamping member, 61_ mounting plate one, 62_ mounting plate two, 63_ sliding rack, 64_ pressing spring, 65_ lifting slot block, 66_ compression spring, 67_ clamping rod, 7_ toggle member, 71_ servo motor, 72_ power shaft, 73_ cam, 74_ toggle lever, 75_ lifting rod, 8_ pulling member, 81_ sector gear, 82_ pulling rack, 83_ pulling rod, 84_ pushing spring, 9_ fixed plate, 10_ communicating pipe.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The utility model provides a cargo truck stores oil storage railway carriage, as shown in fig. 1-8, including bottom plate 1, installation shell 2, damper assembly 3, control buffer assembly 4 and oil transportation subassembly 5, bottom plate 1 top fixed mounting has installation shell 2, is provided with damper assembly 3 on the installation shell 2, and control buffer assembly 4 sliding connection is on installation shell 2, is provided with the oil transportation subassembly 5 that is used for carrying diesel oil on the installation shell 2 equally.

The damping component 3 comprises a four-corner column 31, a supporting spring 32 and a damping sliding plate 33, the diesel engine oil storage device comprises sliding blocks 34, an oil storage tank 35, a slotted swing rod 36 and a torsion spring 37, wherein two pairs of four-corner columns 31 are welded on the inner bottom surface of an installation shell 2, damping sliding plates 33 are connected to the two pairs of four-corner columns 31 in a sliding mode, two pairs of supporting springs 32 are fixedly connected to the damping sliding plates 33, one ends of the supporting springs 32 far away from the damping sliding plates 33 are fixedly connected with the installation shell 2, two sliding blocks 34 are connected to the damping sliding plates 33 in a sliding mode, the oil storage tank 35 used for storing diesel oil is supported on the top surfaces of the two sliding blocks 34, slotted swing rods 36 are rotatably connected to two sides in the installation shell 2, the slotted swing rods 36 are in limiting fit with the oil storage tank 35, the torsion spring 37 is fixedly connected to the slotted swing rod 36, one end of the torsion spring 37 far away from the slotted swing rod 36 is connected with the installation shell 2, and the torsion spring 37 is used for causing resistance to the slotted swing rods 36.

The left and right buffer assembly 4 comprises movable columns 41, a buffer plate 42 and buffer springs 43, two pairs of movable columns 41 are connected to the installation shell 2 in a sliding mode, the buffer plate 42 is welded to one end of each of the two movable columns 41 on the same side, the buffer plate 42 is used for blocking the oil storage tank 35, one side of the buffer plate 42 is connected with a pair of buffer springs 43, and one end, far away from the buffer plate 42, of each buffer spring 43 is fixedly connected with the installation shell 2.

The oil delivery assembly 5 comprises an oil delivery pipe 51, a rotating rod 52, a blocking disc 53 and a rotating gear 54, the oil delivery pipe 51 is slidably connected on the installation shell 2, the oil delivery pipe 51 is connected with the oil storage tank 35, the rotating rod 52 is rotatably connected on the oil delivery pipe 51, the blocking disc 53 is arranged on the rotating rod 52, the blocking disc 53 is positioned in the oil delivery pipe 51, the oil delivery pipe 51 is blocked by the blocking disc 53, and the rotating gear 54 is fixedly connected on the rotating rod 52.

The equipment is arranged between a large truck head and a carriage, diesel oil is stored in the oil storage tank 35, one end of the oil delivery pipe 51 is connected with the truck oil tank, and the diesel oil in the oil delivery pipe 51 can be blocked by the blocking disc 53, so that the diesel oil is prevented from being discharged from the oil delivery pipe 51. When the truck runs on a sloping road surface at a high speed, the truck body of the truck shakes to cause the oil storage tank 35 and the upper device to shake up and down in a reciprocating manner, the damping sliding plate 33 and the upper device thereof can be buffered through the action of the supporting spring 32, the damping sliding plate 33 and the upper device thereof are prevented from shaking up and down violently, when the oil storage tank 35 moves upwards, the oil storage tank 35 can push the slotted swing rod 36 to swing upwards, the torsion spring 37 can cause resistance to the slotted swing rod 36, and the oil storage tank 35 is prevented from moving upwards too much.

When the truck is decelerated suddenly, due to inertia, diesel oil in the oil storage tank 35 flows forwards, the diesel oil pushes the oil storage tank 35 to move forwards, the oil storage tank 35 pushes one of the buffer plates 42 to move forwards, then the diesel oil flows backwards, the oil storage tank 35 pushes the other buffer plate 42 to move backwards, the buffer plates 42 are buffered through the action of the buffer springs 43, the buffer plates 42 block the oil storage tank 35, and the forward and backward movement strokes of the oil storage tank 35 are reduced.

Example 2

On the basis of the embodiment 1, as shown in fig. 6 to 7, the oil delivery pipe device further comprises a clamping assembly 6, the clamping assembly 6 is arranged on the oil delivery pipe 51, the clamping assembly 6 is used for clamping the rotating gear 54, the clamping assembly 6 comprises a first mounting plate 61, a second mounting plate 62, a sliding rack 63, an extrusion spring 64, a lifting groove block 65, a compression spring 66 and a clamping rod 67, the first mounting plate 61 is welded on the oil delivery pipe 51, the second mounting plate 62 is also arranged on the oil delivery pipe 51, the first mounting plate 61 and the second mounting plate 62 are jointly and slidably connected with the sliding rack 63, the sliding rack 63 is meshed with the rotating gear 54, the sliding rack 63 is used for clamping the rotating gear 54, the four extrusion springs 64 are sleeved on the sliding rack 63, the sliding rack 63 is in contact with one end of the extrusion spring 64, wherein the other ends of the two extrusion springs 64 are in contact with the first mounting plate 61, the other ends of the two extrusion springs 64 are in contact with the second mounting plate 62, the lifting groove block 65 is connected to the first mounting plate 61 in a lifting mode, a compression spring 66 is fixedly connected to the top surface of the lifting groove block 65, one end, far away from the compression spring 66, of the lifting groove block 65 is connected with the first mounting plate 61, a clamping rod 67 is connected to the lifting groove block 65 in a sliding mode, the clamping rod 67 is used for clamping the sliding rack 63, and the clamping rod 67 is in limit connection with the sliding rack 63.

When the equipment shakes left and right, the clamping rod 67 clamps the sliding rack 63, the sliding rack 63 can be prevented from moving, the sliding rack 63 can clamp the rotating gear 54, the blocking disc 53 is prevented from rotating to open the oil delivery pipe 51, and diesel oil is prevented from flowing out from a gap between the blocking disc 53 and the oil delivery pipe 51.

Example 3

On the basis of the embodiment 2, as shown in fig. 9 to 10, the electronic device further includes a toggle assembly 7, the base plate 1 is provided with the toggle assembly 7, the toggle assembly 7 includes a servo motor 71, a power shaft 72, a convex disc 73, a toggle rod 74 and a lifting rod 75, the servo motor 71 is fixedly installed on the base plate 1, the power shaft 72 is welded at the top end of an output shaft of the servo motor 71, the convex disc 73 is welded at the top end of the power shaft 72 far away from the servo motor 71, the toggle rod 74 is slidably connected to the base plate 1, the toggle rod 74 is in contact with the convex disc 73, the convex disc 73 is used for pushing the toggle rod 74 and the device thereon to move upwards, the lifting rod 75 is welded at one end of the toggle rod 74, and the clamping rod 67 is slidably connected to the lifting rod 75.

Still including pulling the subassembly 8, sliding connection has pulling the subassembly 8 on the bottom plate 1, pulling the subassembly 8 including sector gear 81, pulling rack 82, pull rod 83 and push spring 84, be provided with sector gear 81 on the power shaft 72 that is close to the flange 73, sliding connection has pulling rack 82 on the bottom plate 1, the rigid coupling has pull rod 83 on the pulling rack 82 of keeping away from bottom plate 1, pull rod 83 and installation shell 2 sliding connection, pull rod 83 and the spacing connection of slip rack 63, be connected with push spring 84 between pull rod 83 and the slip rack 63.

When the diesel quantity of the truck oil tank is insufficient, a driver starts the servo motor 71, an output shaft of the servo motor 71 rotates to drive the power shaft 72 and the upper device to rotate, the convex disc 73 pushes the shift lever 74 and the upper device to move upwards, the clamping rod 67 does not block the sliding rack 63 any more, and then the sector gear 81 rotates and is meshed with the pulling rack 82, the sector gear 81 drives the pulling rack 82 and the pull rod 83 to move towards the direction away from the rotating rod 52, the pull rod 83 pushes the sliding rack 63 to move towards the direction close to the power shaft 72 through the pushing spring 84, the sliding rack 63 drives the rotating gear 54 and the upper device to rotate, the blocking disc 53 does not block the oil delivery pipe 51 any more, and the oil delivery pipe 51 can deliver the diesel into the truck oil tank.

When the sector gear 81 is separated from the pulling rack 82, the extrusion spring 64 is reset to enable the sliding rack 63 to move towards the direction away from the power shaft 72, the sliding rack 63 pushes the pull rod 83 and the pulling rack 82 to move towards the direction close to the rotating rod 52 through the pushing spring 84, then the convex disc 73 is separated from the shift lever 74, the compressed compression spring 66 is reset to drive the lifting groove block 65 and the devices on the lifting groove block to move downwards, the clamping rod 67 clamps the sliding rack 63, and after diesel oil is supplemented, a driver closes the servo motor 71 to stop the operation of the equipment.

Example 4

In addition to embodiment 3, as shown in fig. 2 and 5, the diesel engine fuel tank further includes three fixed grooved plates 9 and a communication pipe 10, the three fixed grooved plates 9 are provided in the fuel tank 35, the fixed grooved plates 9 are used for applying resistance to diesel fuel in the fuel tank 35, and the communication pipe 10 is fixedly connected to the fuel tank 35.

When the truck decelerates suddenly, the diesel oil in the oil storage tank 35 flows forwards, the fixed slotted plate 9 can apply resistance to the diesel oil in the oil storage tank 35, the diesel oil is prevented from flowing too fast, and the large front-back shaking amplitude of the oil storage tank 35 is avoided. When the truck goes up or down a slope, the truck inclines, diesel oil in the oil storage tank 35 flows to one side, and the communication pipe 10 can convey the diesel oil flowing to one side to the other side, so that the stability of the oil storage tank 35 is maintained.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.