阅读说明：本技术 一种防水建筑模板加工用木屑筛选装置及使用方法 (Wood chip screening device for processing waterproof building template and using method ) 是由 赵旭 于 2021-07-28 设计创作，主要内容包括：本发明涉及防水建筑模板生产技术领域,且公开了一种防水建筑模板加工用木屑筛选装置及使用方法,包括底座,所述底座的顶部固定安装有分选仓,所述分选仓的顶部固定安装有防护壳,所述防护壳的内部活动安装有分离筒,所述防护壳的右侧固定安装有进料壳,所述进料壳的内部活动安装有与分离筒固定连接的送料螺旋杆,所述进料壳的顶部固定安装有储料斗,所述防护壳的外部固定安装有与分离筒传动连接的驱动机构,所述分选仓的左侧固定安装有与防护壳底部连通的破碎机构。该防水建筑模板加工用木屑筛选装置及使用方法,可有效降低对环境的噪音污染与灰尘污染,提高加工环境的空气质量,同时可减少作业人员加工时的步骤,提高加工效率。(The invention relates to the technical field of waterproof building template production, and discloses a sawdust screening device for processing a waterproof building template and a using method thereof. The wood chip screening device for processing the waterproof building template and the use method can effectively reduce noise pollution and dust pollution to the environment, improve the air quality of the processing environment, reduce the steps of operators in processing and improve the processing efficiency.)

1. The utility model provides a processing of waterproof building templates uses wooden bits sieving mechanism, includes base (1), its characterized in that: the separation device is characterized in that a separation bin (2) is fixedly mounted at the top of the base (1), a protective shell (3) is fixedly mounted at the top of the separation bin (2), a separating cylinder (4) is movably mounted inside the protective shell (3), a feeding shell (5) is fixedly mounted on the right side of the protective shell (3), a feeding screw rod (6) fixedly connected with the separating cylinder (4) is movably mounted inside the feeding shell (5), a storage hopper (7) is fixedly mounted at the top of the feeding shell (5), a driving mechanism (8) in transmission connection with the separating cylinder (4) is fixedly mounted outside the protective shell (3), a crushing mechanism (9) communicated with the bottom of the protective shell (3) is fixedly mounted on the left side of the separation bin (2), a plurality of blocking nets (10) are fixedly mounted on the back of the inner wall of the separation bin (2), and two collecting hoppers (11) are fixedly mounted inside the base (1), the bottom of the collecting hopper (11) is communicated with a discharge pipe (12), the front of the sorting bin (2) is communicated with an air inlet pipe (13), a centrifugal fan (14) communicated with the air inlet pipe (13) is fixedly installed outside the sorting bin (2), the back of the sorting bin (2) is communicated with an air guide pipe (15), and a cyclone separator (16) communicated with the air guide pipe (15) is fixedly installed outside the sorting bin (2).

2. The waterproof building template processing sawdust screening device of claim 1, which is characterized in that: the separating cylinder (4) comprises a net cylinder, a spiral piece and a fixing frame, the number of the net cylinder is two, the net cylinder is fixedly connected with the net cylinder, two, the spiral piece is fixedly arranged in the net cylinder, the fixing frame is fixedly connected with the feeding spiral rod (6), and the fixing frame is fixedly connected with the driving mechanism (8).

3. The waterproof building template processing sawdust screening device of claim 1, which is characterized in that: actuating mechanism (8) are including driving motor, connecting axle, drive belt and safety cover, driving motor and protecting crust (3) fixed connection, safety cover and protecting crust (3) fixed connection, connecting axle and cylinder (4) fixed connection just extend to the inside of safety cover, the connecting axle passes through the drive belt transmission with driving motor's output and is connected.

4. The waterproof building template processing sawdust screening device of claim 1, which is characterized in that: broken mechanism (9) are including operation storehouse (91), inlet pipe (92), gear motor (93), crushing roller (94) and discharge pipe (95), operation storehouse (91) and sorting bin (2) fixed connection, inlet pipe (92) intercommunication is passed through with the bottom of protecting crust (3) in the top in operation storehouse (91), the left side fixed mounting in operation storehouse (91) has gear motor (93), the inside movable mounting in operation storehouse (91) has at least for two and with gear motor (93) transmission be connected crushing roller (94), the bottom intercommunication in operation storehouse (91) has discharge pipe (95).

5. The waterproof building template processing sawdust screening device of claim 1, which is characterized in that: the interior fixed mounting of separation storehouse (2) has the division board, the division board is located the relative one side of two collecting hoppers (11) and with two collecting hoppers (11) fixed connection.

6. The waterproof building template processing sawdust screening device of claim 1, which is characterized in that: the material collecting hoppers (11) are arranged in a conical shape, and the two material collecting hoppers (11) are distributed in a bilateral symmetry mode.

7. The waterproof building template processing sawdust screening device of claim 1, which is characterized in that: the left side of feeding shell (5) runs through the right side of protecting crust (3) and extends to the inside of separating drum (4), the bottom fixed mounting of base (1) has the supporting leg.

8. The waterproof building template processing sawdust screening device of claim 1, which is characterized in that: the front of the sorting bin (2) is fixedly provided with connecting frames communicated with the air inlet pipe (13), and the number of the connecting frames is the same as that of the blocking nets (10).

9. The use method of the sawdust screening device for processing the waterproof building templates, which is suitable for the sawdust screening device for processing the waterproof building templates in any one of claims 1 to 8, is characterized by comprising the following steps:

placing the crushed sawdust into a storage hopper (7), wherein the sawdust enters the feeding shell (5) through the storage hopper (7);

the driving mechanism (8) drives the separating cylinder (4) and the feeding screw rod (6) to rotate, and the feeding screw rod (6) pushes the sawdust into the separating cylinder (4);

the rotating separating cylinder (4) pushes the sawdust leftwards, the sawdust is separated in the pushing process, large sawdust which cannot be utilized is discharged from the left end of the separating cylinder (4), enters the crushing mechanism (9) to be crushed and discharged, and the crushed sawdust can be placed in the storage hopper (7) again to be screened again;

the small sawdust screened out from the right end of the separating cylinder (4) and the large sawdust screened out from the left end fall downwards and enter the sorting bin (2), the outside air is sent into the sorting bin (2) through the air inlet pipe (13) by the centrifugal fan (14), the powder sawdust is sent into the air guide pipe (15), the powder is separated from the air through the cyclone separator (16), and the powder is discharged from the bottom;

the smaller wood chips and the larger wood chips separated from the powder are separately collected by two collecting hoppers (11) and are respectively discharged by two discharging pipes (12).

Technical Field

The invention relates to the technical field of waterproof building template production, in particular to a sawdust screening device for waterproof building template processing and a using method thereof.

Background

The building formwork is a temporary supporting structure, which is manufactured according to the design requirement, so that a concrete structure and a member are formed according to the specified position and geometric dimension, the correct position of the concrete structure and the member is kept, the self weight of the building formwork and the external load acting on the building formwork are borne, the aim of formwork engineering is fulfilled, the quality and the construction safety of the concrete engineering are ensured, the construction progress is accelerated, and the engineering cost is reduced, wherein the wood-cement compound formwork is wide in use, low in production and purchase cost and mainly formed by wood chip gluing and pressing processing.

The existing wood chip screening device for processing the waterproof building template and the using method thereof solve the problems that the existing wood chip screening device for processing the waterproof building template and the using method thereof are provided, the vibration sieve is usually adopted for screening operation, large noise can be generated in the screening process, large waste can not be directly treated, multiple manual transfer is needed, secondary screening is carried out after crushing, small wood chips and wood chip powder are easily mixed and are difficult to completely separate, and the production quality of the building template is influenced.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a sawdust screening device for processing a waterproof building template and a using method thereof, which have the advantages of saving labor and the like, and solve the problems that the conventional sawdust screening device for processing the waterproof building template usually adopts a vibrating screen for screening operation, generates relatively large noise in the screening process, large wastes cannot be directly treated, the large wastes need to be manually transported for many times, and are screened again after being crushed, and meanwhile, small sawdust and sawdust powder are easily mixed and are difficult to completely separate, and the production quality of the building template is influenced.

(II) technical scheme

The technical scheme for solving the technical problems is as follows: a wood chip screening device for processing a waterproof building template comprises a base, wherein a separation bin is fixedly mounted at the top of the base, a protective shell is fixedly mounted at the top of the separation bin, a separating cylinder is movably mounted in the protective shell, a feeding shell is fixedly mounted on the right side of the protective shell, a feeding screw rod fixedly connected with the separating cylinder is movably mounted in the feeding shell, a storage hopper is fixedly mounted at the top of the feeding shell, a driving mechanism connected with the separating cylinder in a transmission manner is fixedly mounted outside the protective shell, a crushing mechanism communicated with the bottom of the protective shell is fixedly mounted on the left side of the separation bin, a plurality of blocking nets are fixedly mounted on the back of the inner wall of the separation bin, two collecting hoppers are fixedly mounted in the base, a discharge pipe is communicated with the bottom of the collecting hoppers, and an air inlet pipe is communicated with the front of the separation bin, the centrifugal fan communicated with the air inlet pipe is fixedly installed on the outer portion of the separation bin, the air guide pipe is communicated with the back face of the separation bin, and the cyclone separator communicated with the air guide pipe is fixedly installed on the outer portion of the separation bin.

A use method of a sawdust screening device for processing a waterproof building template comprises the following steps:

placing the crushed sawdust into the storage hopper, and enabling the sawdust to enter the feeding shell through the storage hopper;

the driving mechanism drives the separating cylinder and the feeding screw rod to rotate, and the feeding screw rod pushes the sawdust into the separating cylinder;

the rotating separating cylinder pushes the sawdust leftwards, the sawdust is separated in the pushing process, large sawdust which cannot be utilized is discharged from the left end of the separating cylinder, enters the crushing mechanism for crushing treatment, is discharged, and can be placed in the storage hopper again for secondary screening;

the small sawdust sieved at the right end of the separating cylinder and the large sawdust sieved at the left end of the separating cylinder fall downwards and enter the sorting bin, outside air is sent into the sorting bin through the air inlet pipe by the centrifugal fan, powder sawdust is sent into the air guide pipe, powder is separated from the air by the cyclone separator, and the powder is discharged from the bottom;

and the smaller sawdust and the larger sawdust separated from the powder are separately concentrated by the two collecting hoppers and are discharged by the two discharging pipes respectively.

The invention has the beneficial effects that:

the wood chip screening device for processing the waterproof building template and the using method thereof drive the separating cylinder and the feeding screw rod to rotate through the driving mechanism, wood chips are placed into the storage hopper through transmission equipment or manpower, the wood chips enter the feeding shell through the storage hopper, the wood chips are pushed to the inside of the separating cylinder through the feeding screw rod, the feeding is more uniform, compared with a vibrating screen, the mutual collision between the wood chips caused by excessive feeding at one time can be avoided, the screening effect is influenced, the rotating separating cylinder pushes the wood chips to the left, the wood chips are separated in the pushing process, the noise is smaller compared with vibration separation, meanwhile, no dust can be generated, the air environment for production and processing is facilitated, large wood chips are discharged from the left end of the separating cylinder, enter the crushing mechanism for crushing treatment, and are discharged after being crushed, the discharged wood chips can be picked by equipment and then put into the storage hopper again, therefore, when the processing operation is reduced, the manpower and the time required by the transportation are reduced, smaller sawdust screened out from the right end of the separating cylinder and larger sawdust screened out from the left end of the separating cylinder fall downwards and enter the separating bin, outside air is sent into the separating bin through the air inlet pipe by the centrifugal fan, powder sawdust is sent into the air guide pipe and is separated from the air through the cyclone separator, the powder and the sawdust are effectively separated in the falling process of the sawdust in a winnowing mode, even the sawdust moving along with the air can be blocked by the blocking net and is only allowed to pass through, the powder is discharged from the bottom of the cyclone separator under the action of gravity, finally, the sawdust is separately concentrated through the two collecting hoppers and is discharged through the two discharging pipes respectively, the noise pollution and the dust pollution to the environment can be effectively reduced, and the air quality of the processing environment is improved, meanwhile, the steps of the operators in the processing process can be reduced, the labor is saved, and the processing efficiency is improved.

On the basis of the technical scheme, the invention can be further improved as follows.

Further, the separation cylinder includes a net cylinder, a spiral piece and a fixing frame, the number of the net cylinder is two, two the net cylinder is fixedly connected, two the inside fixed mounting of the net cylinder has the spiral piece, two the inside of the net cylinder has the fixing frame, the right side the fixing frame is fixedly connected with the feeding spiral rod, and the left side the fixing frame is fixedly connected with the driving mechanism.

The beneficial effect who adopts above-mentioned further scheme is that, two net section of thick bamboo that set up can carry out twice separation to the saw-dust that gets into, separates great and less saw-dust, and the flight of setting can be in the rotation in-process, with the saw-dust to the left side transmission, and two mounts that set up can drive the pay-off hob and carry out the synchronous revolution material loading in net section of thick bamboo pivoted.

Further, actuating mechanism includes driving motor, connecting axle, drive belt and safety cover, driving motor and protective housing fixed connection, safety cover and protective housing fixed connection, connecting axle and cylinder fixed connection just extend to the inside of safety cover, the connecting axle passes through the drive belt transmission with driving motor's output and is connected.

Adopt above-mentioned further scheme's beneficial effect be, driving motor accessible drive connecting axle rotates for the cylinder rotates, and the safety cover is used for protecting the tip of drive belt and connecting axle.

Further, broken mechanism includes operation storehouse, inlet pipe, gear motor, crushing roller and discharge pipe, operation storehouse and sorting bin fixed connection, the inlet pipe intercommunication is passed through with the bottom of protecting crust in the top in operation storehouse, the left side fixed mounting in operation storehouse has gear motor, the inside movable mounting in operation storehouse has at least two crushing rollers of being connected with the gear motor transmission, the bottom intercommunication in operation storehouse has the discharge pipe.

Adopt the beneficial effect of above-mentioned further scheme to be, the inside in bold saw-dust gets into the operation storehouse through the inlet pipe, has gear motor to drive the crushing roller and rotates, and the crushing roller carries out the ejection of compact through the discharge pipe after with the bold saw-dust breakage.

Further, the inside fixed mounting in separation storehouse has the division board, the division board is located two collecting hopper's relative one side and with two collecting hopper fixed connection.

Adopt above-mentioned further scheme's beneficial effect to be, the division board that sets up can be two parts with the inside partition in sorting bin, avoids great saw-dust and less saw-dust in sorting bin, produces crisscross when dropping downwards.

Furthermore, the aggregate bins are arranged in a conical shape, and the two aggregate bins are distributed in a bilateral symmetry mode.

Adopt above-mentioned further scheme's beneficial effect be, the aggregate bin of toper setting can cushion the whereabouts saw-dust to make dispersed saw-dust collect.

Further, the left side of feed shell runs through the right side of protective housing and extends to the inside of separating cylinder, the bottom fixed mounting of base has the supporting leg.

Adopt above-mentioned further scheme's beneficial effect to be, can make the saw-dust when leaving the feeding shell, in getting into the knockout drum completely, avoid the saw-dust to get into in the sorting bin directly from the clearance.

Furthermore, the front of the sorting bin is fixedly provided with connecting frames communicated with the air inlet pipe, and the number of the connecting frames is the same as that of the blocking nets.

The beneficial effect of adopting above-mentioned further scheme is that, the air that the air-supply line sent into can be shunted to the link frame that sets up, forms the convection current with the guide duct at the arresting barrier back, can be better with powder and saw-dust separation.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a front view of the present invention;

FIG. 3 is a rear view of the present invention;

fig. 4 is a schematic structural diagram of the crushing mechanism of the present invention.

In the figure: 1. a base; 2. a sorting bin; 3. a protective shell; 4. a separation cylinder; 5. a feed shell; 6. feeding a screw rod; 7. a storage hopper; 8. a drive mechanism; 9. a crushing mechanism; 91. an operation bin; 92. a feed pipe; 93. a reduction motor; 94. a crushing roller; 95. a discharge pipe; 10. a barrier net; 11. a collection hopper; 12. a discharge pipe; 13. an air inlet pipe; 14. a centrifugal fan; 15. an air guide pipe; 16. a cyclone separator.

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.

In the embodiment, as shown in fig. 1-3, the wood chip screening device for processing the waterproof building template and the using method thereof comprise a base 1, wherein a separation bin 2 is fixedly installed at the top of the base 1, a protective shell 3 is fixedly installed at the top of the separation bin 2, a separation cylinder 4 is movably installed inside the protective shell 3, a feeding shell 5 is fixedly installed at the right side of the protective shell 3, a feeding screw rod 6 fixedly connected with the separation cylinder 4 is movably installed inside the feeding shell 5, a storage hopper 7 is fixedly installed at the top of the feeding shell 5, crushed wood chips are placed inside the storage hopper 7, and the wood chips enter the feeding shell 5 through the storage hopper 7;

a driving mechanism 8 in transmission connection with the separating cylinder 4 is fixedly arranged outside the protective shell 3, the driving mechanism 8 drives the separating cylinder 4 and the feeding screw rod 6 to rotate, and the wood chips are pushed into the separating cylinder 4 by the feeding screw rod 6;

a crushing mechanism 9 communicated with the bottom of the protective shell 3 is fixedly arranged on the left side of the sorting bin 2, the rotating separating cylinder 4 pushes the sawdust leftwards, the sawdust is separated in the pushing process, large sawdust which cannot be utilized is discharged from the left end of the separating cylinder 4, enters the crushing mechanism 9 to be crushed and discharged, and the crushed sawdust can be placed into the storage hopper 7 again to be screened again;

the back of the inner wall of the separation bin 2 is fixedly provided with a plurality of arresting nets 10, the inside of the base 1 is fixedly provided with two collecting hoppers 11, the bottom of each collecting hopper 11 is communicated with a discharge pipe 12, the front of the separation bin 2 is communicated with an air inlet pipe 13, the outside of the separation bin 2 is fixedly provided with a centrifugal fan 14 communicated with the air inlet pipe 13, the back of the separation bin 2 is communicated with an air guide pipe 15, and the outside of the separation bin 2 is fixedly provided with a cyclone separator 16 communicated with the air guide pipe 15.

The small sawdust screened out from the right end of the separating cylinder 4 and the large sawdust screened out from the left end fall downwards and enter the sorting bin 2, the outside air is sent into the sorting bin 2 through the air inlet pipe 13 by the centrifugal fan 14, the powder sawdust is sent into the air guide pipe 15, the powder is separated from the air through the cyclone separator 16, and the powder is discharged from the bottom;

the smaller wood chips and the larger wood chips separated from the powder are separately collected by the two collecting hoppers 11 and are discharged through the two discharging pipes 12 respectively.

Specifically, the separation cylinder 4 comprises two net cylinders, spiral pieces and fixing frames, the two net cylinders are fixedly connected, the spiral pieces are fixedly mounted inside the two net cylinders, the fixing frames are fixedly mounted inside the two net cylinders, the right fixing frame is fixedly connected with the feeding spiral rod 6, and the left fixing frame is fixedly connected with the driving mechanism 8;

two net section of thick bamboo that set up can carry out twice separation to the saw-dust that gets into, separates great and less saw-dust, and the flight of setting can be at the rotation in-process, with the saw-dust to the left side transmission, and two mounts of setting can drive pay-off hob 6 and carry out the synchronous revolution material loading in net section of thick bamboo pivoted.

Specifically, actuating mechanism 8 includes driving motor, connecting axle, drive belt and safety cover, driving motor and 3 fixed connection of protecting crust, safety cover and 3 fixed connection of protecting crust, connecting axle and cylinder 4 fixed connection and extend to the inside of safety cover, and the connecting axle passes through the drive belt transmission with driving motor's output and is connected.

Adopt above-mentioned further scheme's beneficial effect be, driving motor accessible drive connecting axle rotates for separating cylinder 4 rotates, and the safety cover is used for protecting the tip of drive belt and connecting axle.

In this embodiment, as shown in the schematic diagram of fig. 4, the crushing mechanism 9 includes a working bin 91, a feeding pipe 92, a speed reduction motor 93, a crushing roller 94 and a discharge pipe 95, the working bin 91 is fixedly connected to the sorting bin 2, the top of the working bin 91 is communicated with the bottom of the protective shell 3 through the feeding pipe 92, the speed reduction motor 93 is fixedly installed on the left side of the working bin 91, at least two crushing rollers 94 in transmission connection with the speed reduction motor 93 are movably installed inside the working bin 91, and the bottom of the working bin 91 is communicated with the discharge pipe 95.

Adopt above-mentioned further scheme's beneficial effect be, the inside that the bold saw-dust got into operation storehouse 91 through inlet pipe 92, has gear motor 93 to drive crushing roller 94 and rotates, and crushing roller 94 carries out the ejection of compact through discharge pipe 95 with the broken back of bold saw-dust.

Further, a partition plate is fixedly mounted inside the sorting bin 2, and the partition plate is located on one side opposite to the two aggregate bins 11 and is fixedly connected with the two aggregate bins 11.

The division board that sets up can be two parts with the inside partition of selecting separately storehouse 2, avoids great saw-dust and less saw-dust in selecting separately storehouse 2, produces crisscross when dropping downwards.

Furthermore, the material collecting hoppers 11 are arranged in a conical shape, and the two material collecting hoppers 11 are distributed in a left-right symmetrical mode;

the collection hopper 11 is provided in a tapered shape to buffer the falling chips and collect the scattered chips.

Furthermore, the left side of the feeding shell 5 penetrates through the right side of the protective shell 3 and extends into the separating cylinder 4, and the bottom of the base 1 is fixedly provided with a supporting leg;

the sawdust can completely enter the separating cylinder 4 when leaving the feeding shell 5, and the sawdust is prevented from directly entering the sorting bin 2 from the gap.

Furthermore, the front of the sorting bin 2 is fixedly provided with connecting frames communicated with the air inlet pipe 13, and the number of the connecting frames is the same as that of the blocking nets 10;

the connecting frame can divide the air sent by the air inlet pipe 13 into separate flows, and the separate flows form convection with the air guide pipe 15 on the back of the barrier net 10, so that the powder and the wood chips can be better separated.

The separation cylinder 4 and the feeding screw rod 6 are driven to rotate by the driving mechanism 8, sawdust is placed into the storage hopper 7 by a transmission device or a manual work, enters the feeding shell 5 through the storage hopper 7, is pushed into the separation cylinder 4 by the feeding screw rod 6, can be fed more uniformly, can avoid mutual collision between the sawdust due to excessive feeding once compared with a vibrating screen, influences the screening effect, is pushed leftwards by the rotating separation cylinder 4, and is separated in the pushing process, has smaller noise relative to vibration separation, does not generate dust, is beneficial to the air environment of production and processing, discharges large sawdust from the left end of the separation cylinder 4, enters the crushing mechanism 9 for crushing treatment, and discharges the sawdust after crushing, can be picked up by equipment and then is thrown into the storage hopper 7 again, therefore, when the processing operation is reduced, the manpower and time required for transportation are reduced, smaller sawdust sieved out from the right end of the separating cylinder 4 and larger sawdust sieved out from the left end drop downwards and enter the inside of the separating bin 2, outside air is sent into the separating bin 2 through the air inlet pipe 13 by the centrifugal fan 14, powder sawdust is sent into the inside of the air guide pipe 15 and is separated from the air through the cyclone separator 16, in the sawdust falling process, the powder and the sawdust are effectively separated through a winnowing mode, even the sawdust moving along with the air can be blocked by the blocking net 10 and is only allowed to pass, the powder is discharged from the bottom of the cyclone separator 16 under the action of gravity, and finally, the sawdust is separately concentrated through the two collecting hoppers 11 and is discharged through the two discharging pipes 12 respectively.

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

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.