阅读说明：本技术 一种高频焊管螺旋式弯管装置 (Spiral pipe bending device for high-frequency welded pipe ) 是由 毛作华 于 2021-08-27 设计创作，主要内容包括：本发明提供一种高频焊管螺旋式弯管装置。所述高频焊管螺旋式弯管装置,包括：工作台；升降结构,所述升降结构设置于所述工作台的顶部,所述升降结构包括电动伸缩杆和两个滑杆。属于高频焊管加工技术领域。本发明提供一种高频焊管螺旋式弯管装置,通过设置升降结构与定位结构配合使用,构成对高频焊管的有效定位和导流部件,其中,通过设置定位结构,利用U型的定位板,对高频焊管进行水平方向限位,使得限位距离更长,同时通过设置两个可以调节的定位滑轮组,通过与高频焊管的外部接触,能够对其外部的两侧起到很好的限位作用,大大增加了对高频焊管弯曲时的定位效果,并能够适应不同大小的高频焊管,在使用时更加灵活。(The invention provides a spiral pipe bending device for a high-frequency welded pipe. Spiral swan neck system of high frequency welded pipe includes: a work table; the lifting structure is arranged at the top of the workbench and comprises an electric telescopic rod and two sliding rods. Belongs to the technical field of high-frequency welded pipe processing. The invention provides a spiral pipe bending device for a high-frequency welded pipe, which is characterized in that a lifting structure and a positioning structure are arranged to be matched for use, so that an effective positioning and flow guiding part for the high-frequency welded pipe is formed, wherein the positioning structure is arranged, a U-shaped positioning plate is utilized to horizontally position the high-frequency welded pipe, so that the limiting distance is longer, two adjustable positioning pulley blocks are arranged, and the two adjustable positioning pulley blocks are contacted with the outside of the high-frequency welded pipe, so that the two sides of the outside of the high-frequency welded pipe can be well limited, the positioning effect of the high-frequency welded pipe during bending is greatly improved, the high-frequency welded pipe bending device can adapt to high-frequency welded pipes with different sizes, and the high-frequency welded pipe bending device is more flexible in use.)

1. The utility model provides a spiral swan neck system of high frequency welded pipe which characterized in that includes: a table (1); the lifting structure (2) is arranged at the top of the workbench (1), the lifting structure (2) comprises an electric telescopic rod (21) and two sliding rods (22), the electric telescopic rod (21) and the sliding rods (22) are fixedly arranged at the top of the workbench (1), the two sliding rods (22) are respectively positioned at the left side and the right side of the electric telescopic rod (21), and a connecting piece (23) is slidably connected to the outer parts of the sliding rods (22);

the positioning structure (3) is arranged at the top of the electric telescopic rod (21), the positioning structure (3) comprises a positioning plate (31), the top of the electric telescopic rod (21) and the middle of the bottom of the positioning plate (31) are fixedly installed, and the two connecting pieces (23) are respectively and fixedly installed on the left side and the right side of the bottom of the positioning plate (31);

the inboard of locating plate (31) is provided with two moving member (32), install a plurality of positioning pulley (33) on moving member (32) side by side, spout (34) have all been seted up to both sides around locating plate (31) inner wall bottom, the bottom of moving member (33) with the inside sliding connection of spout (34), it is connected with rotating piece (35) to rotate on locating plate (31), the outside of rotating piece (35) with the inside threaded connection of moving member (33).

2. The high-frequency welded pipe helical pipe bending device according to claim 1, wherein the positioning plate (31) is configured as a U-shaped long plate, the rear end of the rotating member (35) is rotatably connected with the inside of the positioning plate (31), and the front end of the rotating member (35) is located on the front surface of the positioning plate (31).

3. A high-frequency welded pipe helical pipe bending device according to claim 1, wherein two moving members (32) are symmetrically arranged in front and back inside the positioning plate (31), and the number of positioning pulleys (33) on the moving members (32) is four.

4. A high-frequency welded pipe helical pipe bending device according to claim 1, wherein a bending structure (4) is arranged on the right side of the top of the workbench (1), the bending structure (4) comprises a driving motor (41) and a bending drum (42), the driving motor (41) is installed at the bottom of the workbench (1), and the bending drum (42) rotates at the top of the workbench (1).

5. A high-frequency welded pipe spiral pipe bending device according to claim 4, wherein the output end of the driving motor (41) is fixedly provided with a driving wheel (43), the bottom of the bending drum (42) is fixedly provided with a driven rotating member (44), and the outer part of the driven rotating member (44) is in transmission connection with the outer part of the driving wheel (43) through a transmission belt.

6. The high-frequency welded pipe spiral pipe bending device according to claim 5, wherein the outer portion of the bending rotary drum (42) is provided with a spiral bending groove (45), and a fixing member (46) is fixedly mounted at the top of the outer portion of the bending rotary drum (42).

7. A high-frequency welded pipe helical pipe bending device according to claim 6, wherein said bending drum (42) is located on the right side of said positioning plate (31), said bending drum (42) being provided in a cylindrical shape.

8. A high-frequency welded pipe helical pipe bending device according to claim 7, wherein a fixed structure (5) is arranged outside the bending drum (42), the fixed structure (5) comprises a connecting block (51), and the connecting block (51) is fixedly arranged on the top of the bending drum (42).

9. The spiral pipe bending device for high-frequency welded pipes according to claim 8, wherein one side of the connecting block (51) is provided with an installation groove (52), one side of the inner surface of the installation groove (52) is communicated with a movable groove (53), and the connecting block (51) is rotatably connected with an adjusting rotating member (54).

10. The high-frequency welded pipe helical pipe bending device according to claim 9, wherein the left end of the adjusting rotating member (54) is rotatably connected with the left side of the inner surface of the movable groove (53), the inner part of the movable groove (53) is slidably connected with a locking block (55), and the outer part of the adjusting rotating member (54) is in threaded connection with the top of the locking block (55).

Technical Field

The invention relates to the field of high-frequency welded pipe processing, in particular to a spiral pipe bending device for a high-frequency welded pipe.

Background

The high-frequency welded pipe is a product produced by heating and melting the edge of a pipe blank by utilizing the skin effect and the proximity effect of high-frequency current after a hot-rolled coil is formed by a forming machine and carrying out pressure welding under the action of a squeeze roll.

When the high-frequency welded pipe is prepared into other workpieces, the high-frequency welded pipe needs to be processed into a spiral shape, so that a spiral pipe bending device is needed, and the spiral pipe bending device is generally composed of a workbench, a bending part, a driving part, a flow guide part and the like.

Among the prior art, when using swan neck system, one end through with high frequency welded tube is fixed on bending part, and its externally mounted is on water conservancy diversion part, rotate through drive arrangement drive bending part, and then carry out the spiral bending to high frequency welded tube, and traditional water conservancy diversion part is mostly the cylinder that vertical direction set up, through the external contact with high frequency welded tube, play spacing and water conservancy diversion effect to high frequency welded tube, but the water conservancy diversion part of cylinder type, structural design is simple relatively, only have the one side to high frequency welded tube contact to play limiting displacement, spacing effect is stable inadequately, and can move about when high frequency welded tube is crooked, and then make the outside of high frequency welded tube and cylinder outside separation or the position deviation appears easily, all can lead to high frequency welded tube crooked and receive the influence.

Therefore, it is necessary to provide a spiral pipe bending device for high-frequency welded pipes to solve the above technical problems.

Disclosure of Invention

The invention provides a spiral pipe bending device for a high-frequency welded pipe, which solves the problem that the limiting effect of the spiral pipe bending device for the high-frequency welded pipe on the outer part of the high-frequency welded pipe is not stable enough.

In order to solve the technical problem, the invention provides a spiral pipe bending device for a high-frequency welded pipe, which comprises:

a work table;

the lifting structure is arranged at the top of the workbench and comprises an electric telescopic rod and two sliding rods, the electric telescopic rod and the sliding rods are fixedly arranged at the top of the workbench, the two sliding rods are respectively positioned at the left side and the right side of the electric telescopic rod, and connecting pieces are slidably connected to the outer parts of the sliding rods;

the positioning structure is arranged at the top of the electric telescopic rod and comprises a positioning plate, the top of the electric telescopic rod and the middle of the bottom of the positioning plate are fixedly installed, and the two connecting pieces are respectively and fixedly installed with the left side and the right side of the bottom of the positioning plate;

the inboard of locating plate is provided with two moving members, install a plurality of location pulleys on the moving member side by side, the spout has all been seted up to both sides around the locating plate inner wall bottom, the bottom of moving member with the inside sliding connection of spout, it is connected with the rotation piece to rotate on the locating plate, the outside of rotating the piece with the inside threaded connection of moving member.

Preferably, the locating plate sets up to the long board of U-shaped, the rear end that rotates the piece with the inside rotation of locating plate is connected, just the front end that rotates the piece is located the front of locating plate.

Preferably, the two moving parts are symmetrically arranged in the positioning plate in a front-back manner, and four positioning pulleys are arranged on the moving parts.

Preferably, a bending structure is arranged on the right side of the top of the workbench, the bending structure comprises a driving motor and a bending rotary drum, the driving motor is mounted at the bottom of the workbench, and the bending rotary drum rotates at the top of the workbench.

Preferably, a driving wheel is fixedly mounted at an output end of the driving motor, a driven rotating member is fixedly mounted at the bottom of the bent rotating drum, and the outside of the driven rotating member is in transmission connection with the outside of the driving wheel through a transmission belt.

Preferably, the outer portion of the curved rotary drum is provided with a spiral curved groove, and a fixing member is fixedly mounted at the top of the outer portion of the curved rotary drum.

Preferably, the curved rotary cylinder is located on the right side of the positioning plate, and the curved rotary cylinder is provided in a cylindrical shape.

Preferably, a fixing structure is arranged outside the curved rotary drum, and the fixing structure comprises a connecting block which is fixedly installed at the top of the curved rotary drum.

Preferably, a mounting groove is formed in one side of the connecting block, a movable groove is communicated with one side of the inner surface of the mounting groove, and the connecting block is rotatably connected with an adjusting rotating piece.

Preferably, the left end of the adjusting rotating piece is rotatably connected with the left side of the inner surface of the movable groove, the locking block is slidably connected inside the movable groove, and the outer portion of the adjusting rotating piece is in threaded connection with the top of the locking block.

Compared with the prior art, the spiral pipe bending device for the high-frequency welded pipe has the following beneficial effects:

the invention provides a spiral pipe bending device for a high-frequency welded pipe, which is characterized in that a lifting structure and a positioning structure are arranged to be matched for use, so that an effective positioning and flow guiding part for the high-frequency welded pipe is formed, wherein the positioning structure is arranged, a U-shaped positioning plate is utilized to horizontally position the high-frequency welded pipe, so that the limiting distance is longer, meanwhile, two adjustable positioning pulley blocks are arranged, and the spiral pipe bending device is in contact with the outside of the high-frequency welded pipe, so that the spiral pipe bending device can play a good limiting role on two sides of the outside of the high-frequency welded pipe on the premise of ensuring the normal movement of the high-frequency welded pipe, greatly improves the positioning effect when the high-frequency welded pipe is bent, can adapt to the high-frequency welded pipes with different sizes, and is more flexible in use;

simultaneously cooperation electric telescopic handle drive locating plate moves along with the high frequency welded tube removes, and then guarantees that the high frequency welded tube can keep the horizontal direction for the bending part and remove for it is more smooth during the bending, faster, can not receive the influence of high frequency welded tube activity simultaneously, and then ensures to remain effective contact with location structure all the time, fine avoided both to appear positional deviation or the separation condition, better satisfied processing demand.

Drawings

FIG. 1 is a schematic structural diagram of a spiral pipe bending device for high-frequency welded pipes according to the present invention;

FIG. 2 is a schematic view of the exterior of the lift structure and positioning structure shown in FIG. 1;

FIG. 3 is a schematic view of the positioning plate shown in FIG. 2;

FIG. 4 is a schematic structural diagram of a second embodiment of a spiral pipe bending apparatus for high-frequency welded pipe according to the present invention;

fig. 5 is a schematic structural view of the inside of the fixing structure shown in fig. 4.

Reference numerals in the figures

1. A work table;

2. a lifting structure;

21. the electric telescopic rod 22, the sliding rod 23 and the connecting piece;

3. a positioning structure;

31. the positioning plate 32, the moving piece 33, the positioning pulley 34, the sliding chute 35 and the rotating piece;

4. a curved structure;

41. the device comprises a driving motor 42, a bending rotary drum 43, a driving wheel 44, a driven rotary part 45, a spiral bending groove 46 and a fixing part;

5. a fixed structure;

51. connecting block 52, mounting groove 53, movable groove 54, adjusting rotating piece 55 and locking block.

Detailed Description

The invention is further described with reference to the following figures and embodiments.

First embodiment

Please refer to fig. 1, fig. 2, and fig. 3, wherein fig. 1 is a schematic structural diagram of a spiral pipe bending device for high-frequency welded pipes according to the present invention; FIG. 2 is a schematic view of the exterior of the lift structure and positioning structure shown in FIG. 1; fig. 3 is a schematic structural view of the inside of the positioning plate shown in fig. 2. Spiral swan neck system of high frequency welded pipe includes:

a work table 1;

the lifting structure 2 is arranged at the top of the workbench 1, the lifting structure 2 comprises an electric telescopic rod 21 and two sliding rods 22, the electric telescopic rod 21 and the sliding rods 22 are both fixedly arranged at the top of the workbench 1, the two sliding rods 22 are respectively positioned at the left side and the right side of the electric telescopic rod 21, and a connecting piece 23 is slidably connected to the outer part of each sliding rod 22;

the positioning structure 3 is arranged at the top of the electric telescopic rod 21, the positioning structure 3 comprises a positioning plate 31, the top of the electric telescopic rod 21 and the middle of the bottom of the positioning plate 31 are fixedly installed, and the two connecting pieces 23 are respectively and fixedly installed with the left side and the right side of the bottom of the positioning plate 31;

the inboard of locating plate 31 is provided with two moving members 32, install a plurality of positioning pulley 33 on the moving member 32 side by side, spout 34 has all been seted up to both sides around the locating plate 31 inner wall bottom, the bottom of moving member 32 with the inside sliding connection of spout 34, it is connected with a rotation piece 35 to rotate on the locating plate 31, the outside of rotating piece 35 with the inside threaded connection of moving member 32.

The electric telescopic rod 21 is externally connected with a power supply, the extension and retraction of the electric telescopic rod are controlled by an external control switch, the positioning plate 31 can be driven to move in the vertical direction through the extension and retraction of the electric telescopic rod 21, so that the position of the positioning plate 31 can be adjusted, the two slide bars 22 are respectively positioned at the left side and the right side of the electric telescopic rod 21, the connecting piece 23 can be limited by being in sliding connection with the two connecting pieces 23, so that the connecting piece 23 can stably slide in the vertical direction outside the slide bars 22, the connecting piece 23 is fixedly connected with the left side and the right side of the bottom of the positioning plate 31 through the connecting pieces 23, and the left side and the right side of the bottom of the positioning plate 31 can be limited, so that the positioning plate 31 can stably move in the vertical direction;

by arranging the lifting structure 2, the lifting structure is mainly used for driving the positioning plate 31 to move in the vertical direction, when the high-frequency welded pipe is bent, the high-frequency welded pipe is gradually bent into a spiral shape, so that the part, which is not bent, of the high-frequency welded pipe can move in the vertical direction, and in order to avoid the separation of the high-frequency welded pipe from the positioning plate 31, the positioning plate 31 is driven by the electric telescopic rod 21 to simultaneously move along with the high-frequency welded pipe, so that the high-frequency welded pipe and the high-frequency welded pipe cannot be separated, meanwhile, the part, which is not bent, of the high-frequency welded pipe can be always kept in a horizontal state, and the normal operation of subsequent bending is ensured;

the positioning plate 31 is provided with a U-shaped section for horizontally placing the high-frequency welded pipe and is positioned right above the workbench 1, the two moving parts 32 are symmetrically arranged in front and back of the inner side of the positioning plate 31 and can slide in the inner side of the positioning plate simultaneously, the positioning pulleys 33 and the moving parts 32 arranged on the positioning plate are made of steel structure materials with higher hardness, and the two positioning pulleys 33 can simultaneously play an effective limiting role on the outer part of the high-frequency welded pipe and cannot obstruct the movement of the high-frequency welded pipe;

rotate the outside front and back both sides of piece 35 and be provided with the opposite screw thread of two kinds of screw threads simultaneously, and set up with the thread groove adaptation that the inside of two moving pieces 32 set up respectively, through rotating piece 35, and under the limiting displacement of spout 34, make two moving pieces 32 can remove in opposite directions simultaneously, and then realize that the interval of two sets of positioning pulley 33 is adjusted, make it adapt to not unidimensional high frequency welded tube simultaneously, ensure to play effectual positioning action to high frequency welded tube, greatly increased the flexibility when locating plate 31 uses.

The locating plate 31 sets up to the long board of U-shaped, the rear end that rotates piece 35 with the inside rotation of locating plate 31 is connected, just the front end that rotates piece 35 is located the front of locating plate 31.

The rotating part 35 is composed of a threaded rod and a knob, the knob part is located on the front face of the positioning plate 31, and the knob is manually rotated by a worker, so that the rotating part 35 can rotate on the positioning plate 31.

Two moving members 32 are arranged in front-back symmetry in the positioning plate 31, and four positioning pulleys 33 are arranged on the moving members 32.

The quantity of positioning pulley 33 is according to moving member 32 length setting, and its quantity is not limited to four, can adjust according to the user demand of reality, through using two sets of positioning pulley 33 respectively with the outside both sides contact of high frequency welded tube, can play fine limiting displacement to it, the more of quantity of positioning pulley 33 then to the outside spacing of high frequency welded tube and water conservancy diversion effect better.

The right side of the top of the workbench 1 is provided with a bending structure 4, the bending structure 4 comprises a driving motor 41 and a bending drum 42, the driving motor 41 is installed at the bottom of the workbench 1, the bending drum 42 rotates at the top of the workbench 1, an output end of the driving motor 41 is fixedly installed with a driving wheel 43, the bottom of the bending drum 42 is fixedly installed with a driven rotating member 44, the outer portion of the driven rotating member 44 is connected with the outer portion of the driving wheel 43 through a transmission belt, the outer portion of the bending drum 42 is provided with a spiral bending groove 45, the top of the outer portion of the bending drum 42 is fixedly installed with a fixing member 46, the bending drum 42 is located at the right side of the positioning plate 31, and the bending drum 42 is provided with a cylindrical shape.

The driving motor 41 is externally connected with a power supply, the operation of the driving motor is controlled by an external switch, the driving motor is mainly used for driving a driving wheel 43 to rotate, the bending rotary drum 42 is a metal cylinder, the bottom of the bending rotary drum is rotationally connected with the top of the workbench 1 and can rotate at the top of the workbench 1, a spiral bending groove 45 is formed in the bending rotary drum and is fixed with one end of a high-frequency welding pipe, after the bending rotary drum 42 rotates, the high-frequency welding pipe can be driven to contract in the spiral bending groove 45 and be shaped into a spiral shape, a driven rotary piece 44 is fixedly installed at the bottom of the bending rotary drum 42 and can drive the bending rotary drum 42 to rotate, the driven rotary piece 44 consists of a rotating shaft and a driving wheel, the driving wheel 43 is in transmission connection with the driving wheel to realize linkage of the driving wheel and the driving wheel, and the final driving of the bending rotary drum 42 to rotate when the driving motor 41 rotates, so as to realize the bending operation of the high-frequency welding pipe, the fixing member 46 is used for fixing one end of the high-frequency welded pipe, a round hole is formed in the fixing member, and the high-frequency welded pipe is directly clamped in the round hole during installation.

The working principle of the spiral pipe bending device for the high-frequency welded pipe provided by the invention is as follows:

when in use, the high-frequency welded pipe is arranged on the positioning plate 31, one end of the high-frequency welded pipe is arranged on the fixing piece 46, and then the distance between the two positioning pulleys 33 is adjusted according to the size of the high-frequency welded pipe;

during adjustment, the rotating part 35 is rotated to drive the two moving parts 32 to move in opposite directions in the horizontal direction, the bottoms of the two moving parts slide in the sliding grooves 34, and then the two positioning pulley 33 sets start to move until the positioning pulleys 33 contact with the outside of the high-frequency welded pipe;

after that, the bending structure 4 is started, so that the driving motor 41 starts to rotate, and the driving gear 43 is driven to rotate, and further the driven rotating part 44 drives the bending rotating drum 42 to rotate, and the high-frequency welded pipe is subjected to a bending action through the rotation of the bending rotating drum, and can be gradually bent and formed along with the rotation of the spiral bending groove 45, and meanwhile, the electric telescopic rod 21 can drive the positioning plate 31 to slowly move downwards under the control of a program, so that the high-frequency welded pipe can continuously and normally move to the position of the bending rotating drum 42 until the high-frequency welded pipe is bent and formed.

Compared with the prior art, the spiral pipe bending device for the high-frequency welded pipe has the following beneficial effects:

the lifting structure 2 and the positioning structure 3 are matched for use, effective positioning and flow guide components for the high-frequency welded pipe are formed, wherein the positioning structure 3 is arranged, the U-shaped positioning plate 31 is utilized to limit the high-frequency welded pipe in the horizontal direction, so that the limiting distance is longer, meanwhile, two adjustable positioning pulley blocks 33 are arranged, and the two adjustable positioning pulley blocks are in contact with the outside of the high-frequency welded pipe, so that the high-frequency welded pipe can be well limited on two sides of the outside of the high-frequency welded pipe on the premise of ensuring the normal movement of the high-frequency welded pipe, the positioning effect of the high-frequency welded pipe during bending is greatly increased, the high-frequency welded pipe can adapt to the high-frequency welded pipes with different sizes, and the high-frequency welded pipe bending machine is more flexible in use;

meanwhile, the electric telescopic rod 21 is matched with the positioning plate 31 to drive the high-frequency welded pipe to move along with the movement of the high-frequency welded pipe, so that the high-frequency welded pipe can be moved in the horizontal direction for the bending part, the bending is smooth and quick, meanwhile, the high-frequency welded pipe cannot be influenced by the movement of the high-frequency welded pipe, so that the high-frequency welded pipe is ensured to be always in effective contact with the positioning structure 3, the position deviation or the separation condition between the high-frequency welded pipe and the positioning structure is well avoided, and the machining requirement is better met.

Second embodiment

Based on a high-frequency welded pipe spiral pipe bending device according to a first embodiment of the present invention, a second embodiment of the present invention provides another high-frequency welded pipe spiral pipe bending device, wherein the second embodiment does not hinder independent implementation of the technical solution of the first embodiment.

Specifically, the invention provides another high-frequency welded pipe spiral pipe bending device which is different in that:

the fixed structure 5 is arranged outside the curved rotary drum 42, the fixed structure 5 comprises a connecting block 51, and the connecting block 51 is fixedly arranged on the top of the curved rotary drum 42.

An installation groove 52 is formed in one side of the connecting block 51, a movable groove 53 is communicated with one side of the inner surface of the installation groove 52, and an adjusting rotating piece 54 is rotatably connected to the connecting block 51.

The left end of the adjusting rotating piece 54 is rotatably connected with the left side of the inner surface of the movable groove 53, the locking block 55 is slidably connected inside the movable groove 53, and the outer part of the adjusting rotating piece 54 is in threaded connection with the top of the locking block 55.

The fixing structure 5 is mainly used for effectively fixing one end of a high-frequency welded pipe, the mounting groove 52 is a mounting position of the end part of the high-frequency welded pipe, one side of the locking block 55 is arranged in an arc shape and is matched with the mounting groove 52 and can slide in the horizontal direction in the mounting groove 52, one side of the locking block 55 is attached to the outside of the high-frequency welded pipe, the effective fixing effect on one end of the locking block 55 can be achieved, the adjusting rotating piece 54 can rotate on the connecting block 51, the threaded groove matched with the adjusting rotating piece 54 is formed in the top of the locking block 55, the locking block 55 can be driven to move in the horizontal direction by rotating the adjusting rotating piece 54, the locking block 55 can be simultaneously adapted to the high-frequency welded pipes with different sizes, the effective fixing effect on the outside of the high-frequency welded pipe can be ensured, one end of the high-frequency welded pipe can be effectively fixed outside the bending rotating drum 42 by arranging the fixing structure 5, meanwhile, the traditional fixed design is changed, the high-frequency welded pipe can be effectively fixed, one end of the high-frequency welded pipe is kept in a stable state when the high-frequency welded pipe is bent, and meanwhile the high-frequency welded pipe can adapt to high-frequency welded pipes of different sizes, so that different processing requirements can be better met.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.