Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a fruit and vegetable cultivation device, solves the technical problem that the rotation cultivation device in the prior art can cause nutrient drops to fall on the surfaces of fruit and vegetable plants in the rotation process, and has the advantage of effectively avoiding the nutrient drops from falling on the surfaces of the fruits and vegetables in the rotation cultivation process.
In order to solve the technical problems, the invention provides the technical scheme that the fruit and vegetable cultivation device comprises a box body, mounting vertical plates are symmetrically arranged on the box body, rotary cultivation mechanisms for cultivating fruits and vegetables in batches are arranged on the mounting vertical plates, plant protection mechanisms for preventing nutrient solution drops from falling onto the surfaces of the fruits and vegetables to cause damage are arranged in the rotary cultivation mechanisms, liquid supply mechanisms for supplying nutrient solution to the roots of the fruits and vegetables are arranged in the box body, light source supply mechanisms are arranged above the box body, the rotary cultivation mechanisms can circularly convey the fruits and vegetables, the roots of the fruits and vegetables intermittently contact with the nutrient solution in the box body in the conveying process, meanwhile, the light source supply mechanisms can give proper illumination to the fruits and vegetables, the rotary cultivation mechanisms comprise rotary supports movably mounted on the mounting vertical plates, a driving motor is fixedly mounted on one side, which is away from the rotary supports, a plurality of rotary bumps are arranged on the rotary supports in the circumferential direction, rectangular frame bodies are fixedly mounted at the lower ends of the rotary bumps, a cultivation bed mechanism for cultivating the cultivation is arranged on the rectangular frame body, a light source supply mechanism is detachably mounted on the inner side of the box body, the box body is internally provided with a nutrient solution pond, and the rotary support is rotatably connected with a plurality of rotary support shafts through bearings, and a rotary liquid drop-receiving drum, and a rotary liquid drop can be fixedly connected to the rotary support can rotate to the rotary support and can rotate a rotary support and drop-preventing drum, and a rotary support can rotate to drop on a rotary drum.
Preferably, the upper end of the rotary lug is rotationally connected with the rotary support, the lower end of the rotary lug is fixedly connected with the rectangular frame body, and the rotary lug is always in a vertical state when the rotary support slowly rotates, so that fruits and vegetables on the rectangular frame body are kept in a vertical state, and falling is prevented.
Preferably, a plurality of groups of limiting round rods are fixedly arranged on the rectangular frame body, so that the cultivation bed mechanism is limited, and the cultivation bed mechanism is prevented from sliding on the rectangular frame body.
Preferably, the cultivation bed mechanism comprises an open box body, wherein fruit and vegetable bodies are planted in the open box body, a plurality of liquid inlet through holes are formed in the bottom of the open box body, sponge fillers for storing nutrient solution are arranged at the lower end of the inner cavity of the open box body, soil fillers are arranged above the sponge fillers, root systems of the fruit and vegetable bodies are located in the soil fillers, and after the nutrient solution enters the interior of the open box body through the liquid inlet through holes, the nutrient solution can be absorbed by the sponge fillers, so that the nutrient solution is continuously provided for the root systems.
Preferably, the limiting round rod is located at two sides of the open box body, the cross section diameter of the open box body is gradually decreased from top to bottom, after the open box body is placed on the rectangular box body by a worker, the open box body is contacted with the anti-slip adhesive tape, and at the moment, the limiting round rod is located at two sides of the open box body, so that the open box body is limited.
Preferably, the lower end of the liquid receiving cylinder is provided with a counterweight square box, and the weight of the lower end of the liquid receiving cylinder can be increased due to the counterweight square box, so that the liquid receiving cylinder cannot synchronously rotate along with the rotating bracket.
Preferably, the bearing assembly comprises a bearing body fixedly mounted on the rotating support, and a connecting rod is arranged between the outer side of the bearing body and the inner wall of the liquid receiving cylinder, so that the liquid receiving cylinder is prevented from moving and interfering with the rotation of the rotating support.
Preferably, the liquid replenishing mechanism comprises a liquid adding pipeline fixedly arranged at the lower end of the box body, the liquid adding pipeline is communicated with the inside of the nutrient solution tank, a second filter plate which is convenient for fishing fruit and vegetable blades is fixedly arranged in the nutrient solution tank, arc-shaped slide ways for recovering redundant nutrient solution are arranged on two sides of the nutrient solution tank, stirring components are symmetrically arranged in the nutrient solution tank, a rotating shaft of the stirring components extends to the outer side of the box body, a driven belt wheel is fixedly sleeved on the rotating shaft, a driving belt wheel is coaxially arranged on the rotating support, a driving belt is arranged between the driving belt wheel and the driven belt wheel, and when the rotating support rotates, the two driven belt wheels are synchronously rotated through the driving belt, so that the stirring components synchronously rotate.
Preferably, the outside of box has seted up the rectangle spout, and movable mounting has the take-up pulley on the rectangle spout, and the inside of rectangle spout is equipped with the tensioning spring who upwards pushes away the take-up pulley to make driving belt be in the state of tightening all the time, guarantee transmission efficiency.
Preferably, the light source supply mechanism comprises a telescopic bracket fixedly installed on the installation vertical plate, a horizontal transverse plate is arranged on the telescopic bracket, an LED lamp strip for providing illumination for fruits and vegetables is arranged on the horizontal transverse plate, and the height of the horizontal transverse plate can be increased along with the extension of the telescopic bracket.
By means of the technical scheme, the invention provides a fruit and vegetable cultivation device, which at least has the following beneficial effects:
1. According to the invention, by arranging the plant protection mechanism and utilizing the mutual coordination between the liquid receiving cylinder and the bearing assembly, nutrient liquid drops remained on the upper open box body in the rotary cultivation process can be prevented from falling on the lower open box body, and adverse effects on the fruit and vegetable cultivation process caused by the falling of the nutrient liquid drops on the fruit and vegetable body can be effectively avoided.
2. According to the invention, by arranging the plant protection mechanism, the liquid receiving cylinder can be always kept in a vertical state by utilizing the mutual matching between the counterweight square box and the first filter plate, so that redundant nutrient solution outside the open box body can be rapidly collected, and the waste can be effectively avoided.
3. According to the invention, the rotary cultivation mechanism is arranged, and the rotary bracket and the rectangular frame body are matched with each other, so that the space utilization rate can be improved to a great extent, the space occupation is reduced, the intermittent nutrient solution supplement for the root system of the fruits and vegetables can be automatically realized, the manual operation of a worker is not required, and the efficiency of the cultivation of the fruits and vegetables can be effectively improved.
4. According to the invention, the rotary cultivation mechanism is arranged, and the rotary protruding blocks are matched with the rectangular frame body, so that the open box body can always keep a vertical state, the stability of the open box body in the cultivation process can be improved, dropping is prevented, and fruits and vegetables can be prevented from touching nutrient solution in the nutrient solution pond.
5. According to the invention, by arranging the cultivation bed mechanism, the sponge filler and the liquid inlet through holes are matched with each other, so that nutrient solution can be continuously and uniformly supplied to fruit and vegetable root systems, the open box body is not required to be soaked in the nutrient solution all the time, cross infection can be effectively prevented, the risk of plant diseases and insect pests is reduced, and meanwhile, the cleanliness of the nutrient solution can be maintained to a certain extent.
6. According to the invention, the liquid supply mechanism is arranged, and the liquid supply pipeline and the stirring assembly are matched, so that the nutrient solution can be rapidly supplied to the inside of the nutrient solution tank, and the nutrient solution can be slowly stirred on the premise of not additionally arranging a drive, the uniformity of the nutrient solution can be effectively improved, and the absorption of fruits and vegetables is facilitated.
7. According to the invention, by arranging the liquid supply mechanism and utilizing the mutual coordination between the arc-shaped slide way and the second filter plate, a worker can conveniently and rapidly salvage fruit and vegetable leaves falling into the nutrient solution tank, and meanwhile, the dropped nutrient solution can be drained and recovered, so that waste can be effectively avoided.
8. The invention utilizes the mutual coordination between the telescopic bracket and the horizontal transverse plate by arranging the light source supply mechanism, not only can continuously provide illumination for fruit and vegetable cultivation, but also can automatically adjust the height of the light source, and can automatically adapt to fruit and vegetable plants in different growth periods, thereby ensuring the illumination uniformity and simultaneously avoiding the collision between the fruit and vegetable and the horizontal transverse plate.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute a limitation on the application. In the drawings:
FIG. 1 is a perspective view of the overall structure of the present invention;
FIG. 2 is a second perspective view of the overall structure of the present invention;
FIG. 3 is a schematic diagram of a rotary cultivating mechanism according to the present invention;
FIG. 4 is a schematic view of a rotating bracket according to the present invention;
FIG. 5 is a schematic diagram of a nutrient solution tank according to the present invention;
FIG. 6 is a schematic view of a structure of a cultivating bed mechanism according to the present invention;
FIG. 7 is a schematic view of a liquid receiving cylinder according to the present invention;
FIG. 8 is a schematic view of a counterweight square box structure in the invention;
FIG. 9 is a schematic view of a liquid replenishment mechanism according to the present invention;
fig. 10 is a schematic view of a light source supply mechanism according to the present invention.
The device comprises a box body 1, a mounting vertical plate 2, a rotating cultivation mechanism 3, a 301, a rotating bracket 302, a driving motor 303, a rotating lug 304, a rectangular frame body 305, an anti-slip adhesive tape 306, a limiting round rod 307, a nutrient solution pond 4, a cultivation bed mechanism 401, an open box body 402, a fruit and vegetable body 403, a liquid inlet hole 404, a sponge filler 405, a soil filler 5, a plant protection mechanism 501, a bearing assembly 502, a liquid receiving cylinder 503, a first filter plate 504, a counterweight square box 6, a liquid supply mechanism 601, a liquid adding pipeline 602, a second filter plate 603, an arc-shaped slideway 604, a stirring assembly 605, a driven pulley 606, a driving pulley 607, a driving belt 608, a tensioning pulley 609, a tensioning spring 7, a light source supply mechanism 701, a telescopic bracket 702, a horizontal transverse plate 703 and an LED lamp belt.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
Most of the traditional fruit and vegetable cultivation devices adopt a flat land cultivation mode, so that the occupied space is large, fruits and vegetables are required to be placed in the nutrient solution all the time, cross infection is easy to occur, and the risk of plant infection diseases and insect pests is increased. In order to solve the technical defect in the prior art, as shown in fig. 1-4, the embodiment provides a fruit and vegetable cultivation device, a rotary cultivation mode is adopted, space utilization rate can be improved to a great extent, space occupation is reduced, intermittent nutrient solution supplement can be automatically carried out on fruit and vegetable root systems, the device box body 1 is symmetrically provided with mounting vertical plates 2, the mounting vertical plates 2 are provided with rotary cultivation mechanisms 3 for cultivating fruits and vegetables in batches, plant protection mechanisms 5 for preventing nutrient solution from dropping on the surfaces of the fruits and vegetables to cause damage are arranged in the rotary cultivation mechanisms 3, liquid supply mechanisms 6 for providing nutrient solution for the fruit and vegetable root systems are arranged in the box body 1, a light source supply mechanism 7 is arranged above the box body 1, the rotary cultivation mechanisms 3 can carry out cyclic conveying on the fruits and vegetables, the fruit and vegetable root systems in the conveying process can intermittently contact with the nutrient solution in the box body 1, and meanwhile, the light source supply mechanism 7 can give proper illumination to the fruits and vegetables.
In order to improve the space utilization and cultivation efficiency as much as possible, the embodiment sets up the rotary cultivation mechanism 3, and in particular, the rotary cultivation mechanism 3 includes the rotary support 301 movably mounted on the mounting riser 2, one side of the mounting riser 2 deviating from the rotary support 301 is fixedly mounted with the driving motor 302, be provided with a plurality of rotary lug 303 along the circumferencial direction on the rotary support 301, the upper end and the rotary support 301 of rotary lug 303 rotate to be connected, the lower extreme and the rectangular frame 304 of rotary lug 303 are fixedly connected, when the rotary support 301 slowly rotates, the rotary lug 303 is in the vertical state all the time, thereby make fruit vegetables on the rectangular frame 304 keep the vertical state, prevent to drop, the lower extreme fixed mounting of rotary lug 303 has rectangular frame 304, the cultivation bed mechanism 4 that is used for cultivating fruit vegetables has been placed on the rectangular frame 304, the inboard demountable mounting of rectangular frame 304 has anti-skidding adhesive tape 305, a plurality of limit round bars 306 on the rectangular frame 304, thereby carry out spacing to cultivation bed mechanism 4, prevent cultivation bed mechanism 4 from sliding on rectangular frame 304, the inside of box 1 has seted up the nutrient solution pond 307, when the rotary support 301 rotates, can make the cultivation bed mechanism 4 circulate with the bottom in the process of rotating, can rotate with the cultivation mechanism 4.
According to the above, when cultivating fruits and vegetables, as shown in fig. 1, a worker will put the open box 401 with the fruits and vegetables planted thereon on the rectangular frame 304, and at this time, the anti-slip adhesive tape 305 and the limit round bar 306 will perform double limiting on the open box 401, thereby ensuring the stability of the fruits and vegetables during the cultivation.
Next, the rotating bracket 301 will slowly rotate under the drive of the driving motor 302, and when the rotating bracket 301 rotates, the plurality of open box bodies 401 will synchronously rotate, and when the open box bodies 401 rotate to the position right below the rotating bracket 301, the bottom of the open box bodies 401 will be located in the nutrient solution pond 307, at this time, the nutrient solution will enter the interior of the open box bodies 401, thereby realizing automatic addition of the nutrient solution.
In addition, the embodiment can enable the open box 401 to always keep in a vertical state by the aid of the mutual matching between the rotary lug 303 and the rectangular frame 304 through the arrangement of the rotary cultivation mechanism 3, so that the space utilization rate can be improved to a great extent, space occupation is reduced, intermittent nutrient solution supplement to a root system of a fruit and vegetable can be automatically achieved, manual operation of workers is not needed, and the fruit and vegetable cultivation efficiency can be effectively improved.
Example two
In order to ensure that the root system of fruits and vegetables can better absorb nutrient solution, on the basis of embodiment one, as shown in fig. 1,2 and 6, on the basis of embodiment one, cultivation bed mechanism 4 is provided, concrete cultivation bed mechanism 4 includes uncovered box body 401, limit round bar 306 is located the both sides of uncovered box body 401, the cross section diameter of uncovered box body 401 decreases from top to bottom in proper order, after the staff puts uncovered box body 401 on rectangular frame body 304, uncovered box body 401 can be contacted with anti-slip adhesive tape 305, at this moment, limit round bar 306 can be located the both sides of uncovered box body 401, thereby carry out the spacing to uncovered box body 401, the inside planting of uncovered box body 401 has fruit and vegetable body 402, a plurality of feed-through hole 403 has been seted up to the bottom of uncovered box body 401, the lower extreme of uncovered box body 401 inner chamber is equipped with the sponge filler 404 of storage nutrient solution, the top of sponge filler 404 is provided with soil filler 405, the root system of fruit and vegetable body 402 is located the inside of soil filler 405, nutrient solution can be continuously absorbed by sponge filler 401 after passing through the feed-through box body 401.
As can be seen from the above description, in the process of circulating the rotary support 301, the bottom of the open box 401 is intermittently immersed in the nutrient solution, and when the open box 401 contacts with the nutrient solution, a certain amount of nutrient solution enters the open box 401 through the liquid inlet holes 403, and at this time, the sponge filler 404 absorbs and stores a certain amount of nutrient solution.
In the process of circulating rotation, the root systems of fruits and vegetables can continuously absorb the nutrient solution from the inside of the sponge filler 404, and when the nutrient solution in the sponge filler 404 is consumed, the open box body 401 can be immersed into the nutrient solution again, so that automatic supply is realized.
This embodiment utilizes the cooperation between sponge filler 404 and the feed liquor through-hole 403 through setting up cultivation bed mechanism 4, can continuously evenly provide the nutrient solution to fruit vegetables root system, does not need to soak uncovered box body 401 in the nutrient solution always, can prevent effectively that cross infection from appearing, reduces the risk of plant diseases and insect pests, also can keep the cleanliness factor of nutrient solution to a certain extent simultaneously.
Example III
The rotary cultivation device in the prior art can bring a part of nutrient solution out of the pool inevitably in the rotation process, so that the consumption of the nutrient solution can be obviously increased, meanwhile, the nutrient solution can be directly dropped onto fruit and vegetable plants, and the leaves of the fruits and vegetables are burnt easily, so that unnecessary trouble is brought. In order to solve the technical defect in the prior art as far as possible, as shown in fig. 1-3, 7 and 8, on the basis of the above embodiment, the present embodiment sets up the plant protection mechanism 5, specifically, the plant protection mechanism 5 includes a bearing assembly 501 coaxially disposed with the rotating support 301, the bearing assembly 501 includes a bearing body fixedly mounted on the rotating support 301, a liquid receiving cylinder 502 is fixedly mounted on the bearing assembly 501, a connecting rod is disposed between the outer side of the bearing assembly and the inner wall of the liquid receiving cylinder 502, thereby ensuring that the liquid receiving cylinder 502 will not cause motion interference with the rotation of the rotating support 301, a first filter plate 503 is fixedly mounted on the liquid receiving cylinder 502, and can receive the dropped nutrient solution, so as to avoid the drop of the nutrient solution onto the fruit and vegetable body 402, a counterweight square box 504 is disposed at the lower end of the liquid receiving cylinder 502, and the weight of the counterweight square box 504 can increase the lower end of the liquid receiving cylinder 502, so that the liquid receiving cylinder 502 will not rotate synchronously with the rotating support 301.
As can be seen from the above, the weight of the bottom of the liquid receiving cylinder 502 is large due to the counterweight square box 504, so that the liquid receiving cylinder 502 will not rotate synchronously with the rotating bracket 301 during the rotation of the rotating bracket 301.
In the process of circularly rotating the rotary support 301, when the two sets of open boxes 401 are in an up-down overlapped state, the nutrient solution remained outside the upper open box 401 can drop into the liquid receiving cylinder 502, and the bottom of the lower open box 401 can be immersed into the nutrient solution.
Next, the worker periodically removes the weight box 504 and collects the nutrient solution from the interior of the docking cylinder 502.
By arranging the plant protection mechanism 5, the mutual matching between the liquid receiving cylinder 502 and the bearing component 501 can prevent nutrient liquid drops remained on the upper open box body 401 from falling on the lower open box body 401 in the rotary cultivation process, and can effectively avoid adverse effects on the fruit and vegetable cultivation process caused by the falling of the nutrient liquid drops on the fruit and vegetable body 402; moreover, this embodiment utilizes the cooperation between counter weight square box 504 and first filter 503 through setting up plant protection machanism 5, can make connect liquid drum 502 remain vertical state all the time to collect fast the outside unnecessary nutrient solution of uncovered box body 401, can effectively avoid extravagant.
Example IV
In order to improve the uniformity of the nutrient solution as much as possible and ensure the cultivation effect, on the basis of the above embodiment, as shown in fig. 1, 5 and 9, the present embodiment sets up the liquid replenishment mechanism 6, specifically, the liquid replenishment mechanism 6 includes a liquid adding pipe 601 fixedly installed at the lower end of the box 1, the liquid adding pipe 601 is communicated with the inside of the nutrient solution tank 307, a second filter plate 602 convenient for salvaging fruit and vegetable blades is fixedly installed in the nutrient solution tank 307, arc-shaped slides 603 for recycling the surplus nutrient solution are provided at both sides of the nutrient solution tank 307, stirring assemblies 604 are symmetrically provided in the inside of the nutrient solution tank 307, the rotation shaft of the stirring assemblies 604 extends to the outside of the box 1, driven pulleys 605 are fixedly sleeved on the rotation shaft, driving pulleys 606 are coaxially provided on the rotation support 301, a driving belt 607 is provided between the driving pulleys 606 and the driven pulleys 605, when the rotation support 301 rotates, the two driven pulleys are synchronously rotated through the driving belt 607, thereby the stirring assemblies 604 synchronously rotate, a rectangular chute is provided at the outside of the box 1, a movable pulley 608 is movably installed on the rectangular chute, tensioning spring 608 is provided in the inside of the rectangular chute, the tensioning pulley 608 is pushed upwards by the tensioning pulley 608, thereby ensuring the driving efficiency to be always in a tight state.
From the above, during the rotation culture, the worker can add the prepared nutrient solution into the nutrient solution tank 307 through the solution adding pipe 601, and the rotation support 301 can still be in a circulating rotation state during the solution adding process, and the two are not interfered with each other.
As shown in fig. 9, when the rotary support 301 rotates, the driven belt pulley 605 is synchronously rotated by the driving belt 607, and when the driven belt pulley 605 rotates, the stirring assembly 604 is synchronously rotated, so that the nutrient solution is slowly stirred, the bottom of the nutrient solution is effectively prevented from precipitating, and the uniformity of the nutrient solution is improved.
Moreover, if the fruit and vegetable leaves fall into the nutrient solution pond 307 during rotation cultivation, the fruit and vegetable leaves can be located above the second filter plate 602, so that the workers can conveniently and quickly salvage the leaves.
In addition, when the open box 401 just moves out of the nutrient solution tank 307, the nutrient solution carried out together falls down and flows back into the nutrient solution tank 307 under the guiding action of the arc-shaped slide 603, so that waste can be effectively prevented.
In the embodiment, by arranging the liquid supply mechanism 6 and utilizing the mutual matching between the liquid adding pipeline 601 and the stirring component 604, the nutrient solution can be rapidly supplied to the inside of the nutrient solution pond 307, and can be slowly stirred on the premise of not additionally arranging a drive, so that the uniformity of the nutrient solution can be effectively improved, and the absorption of fruits and vegetables is facilitated; moreover, this embodiment utilizes the cooperation between arc slide 603 and the second filter 602 through setting up liquid supply mechanism 6, and the staff of being convenient for salvages fast to dropping the inside fruit and vegetable blade of nutrient solution pond 307, also can drain the recovery to the nutrient solution of drip simultaneously, can effectively avoid extravagant.
Example five
In order to provide certain illumination for fruit and vegetable plants and promote normal growth of fruits and vegetables, on the basis of the above embodiments, as shown in fig. 1,2 and 10, the present embodiment is provided with a light source supply mechanism 7, specifically, the light source supply mechanism 7 includes a telescopic bracket 701 fixedly installed on the installation riser 2, a horizontal transverse plate 702 is provided on the telescopic bracket 701, an LED lamp strip 703 for providing illumination for fruits and vegetables is provided on the horizontal transverse plate 702, and the height of the horizontal transverse plate 702 can be increased along with the extension of the telescopic bracket 701.
As can be seen from the above, the LED lamp strip 703 can provide illumination for fruits and vegetables during the process of rotating cultivation.
Moreover, along with the gradual increase of cultivation time, the height of fruit and vegetable plants can also be continuously increased, at this moment, the horizontal transverse plate 702 can upwards move under the effect of the telescopic bracket 701, so that the height of the LED lamp strip 703 is increased, and the fruit and vegetable is prevented from colliding with the horizontal transverse plate 702 in the process of rotary cultivation.
The embodiment utilizes the mutual cooperation between the telescopic bracket 701 and the horizontal transverse plate 702 by arranging the light source supply mechanism 7, can continuously provide illumination for fruit and vegetable cultivation, can automatically adjust the height of the light source, and can automatically adapt to fruit and vegetable plants in different growth periods, thereby ensuring the illumination uniformity and avoiding the collision between fruits and vegetables and the horizontal transverse plate 702.
The control mode of the invention is automatically controlled by the controller, the control circuit of the controller can be realized by simple programming of a person skilled in the art, the supply of power also belongs to common knowledge in the art, and the invention is mainly used for protecting a mechanical device, so the invention does not explain the control mode and circuit connection in detail.
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.