阅读说明：本技术 一种频谱分析仪的信号扫描方法及频谱分析仪 (Signal scanning method of spectrum analyzer and spectrum analyzer ) 是由 唐元 于 2021-07-15 设计创作，主要内容包括：本发明涉及分析仪技术领域,具体为一种频谱分析仪的信号扫描方法及频谱分析仪,其方法包括如下步骤：准备频谱分析仪,且频谱分析仪包括信号接收模块、转换器、中央处理器、显示屏控制模块、显示屏和储存模块,检查频谱分析仪所有的连接线缆和连接器是否有损坏,若有损坏更换为合格的,若没有损坏则将合格的线缆和连接器连接到频谱分析仪上,然后打开中央处理器频谱分析仪。本发明提出了一种频谱分析仪,能够使分析仪本体旋转至合适的角度,并且方便进行升降,通过第二弹簧的回复力能够使密封块向上移动,从而增加吸盘的真空度保证吸附的稳定性,使分析仪本体稳稳的固定在桌面上,避免出现不利影响。(The invention relates to the technical field of analyzers, in particular to a signal scanning method of a spectrum analyzer and the spectrum analyzer, wherein the method comprises the following steps: preparing a spectrum analyzer, wherein the spectrum analyzer comprises a signal receiving module, a converter, a central processing unit, a display screen control module, a display screen and a storage module, checking whether all connecting cables and connectors of the spectrum analyzer are damaged or not, replacing the connecting cables and the connectors into qualified cables and connectors if the connecting cables and the connectors are damaged, and connecting the qualified cables and the connectors to the spectrum analyzer if the connecting cables and the connectors are not damaged, and then opening the central processing unit spectrum analyzer. The invention provides a spectrum analyzer, which can enable an analyzer body to rotate to a proper angle and be convenient to lift, and a sealing block can move upwards through the restoring force of a second spring, so that the vacuum degree of a sucker is increased, the adsorption stability is ensured, the analyzer body is stably fixed on a table top, and adverse effects are avoided.)

1. A method for scanning a signal of a spectrum analyzer, the method comprising the steps of:

s1: preparing a spectrum analyzer, wherein the spectrum analyzer comprises a signal receiving module, a converter, a central processing unit, a display screen control module, a display screen and a storage module, checking whether all connecting cables and connectors of the spectrum analyzer are damaged or not, if the connecting cables and the connectors are damaged, replacing the connecting cables and the connectors into qualified cables and connectors, if the connecting cables and the connectors are not damaged, connecting the qualified cables and connectors to the spectrum analyzer, and then opening the central processing unit;

s2: the signal receiving module scans signals, and then converts the scanned signal data into pulse signal data through a converter;

s3: the pulse signal data are transmitted to the central processing unit through the converter, the central processing unit can control the signal receiving module to stop receiving signals, meanwhile, the central processing unit drives the display screen to display the pulse signals through the display screen control module, the central processing unit can transmit the pulse signal data to the data storage module, and the data storage module can store the pulse signal data.

2. The signal scanning method of a spectrum analyzer as claimed in claim 1, wherein: the output end of the signal receiving module is electrically connected with the input end of the converter, the output end of the converter is electrically connected with the input end of the central processing unit, and the output end of the central processing unit is electrically connected with the input end of the signal receiving module.

3. The signal scanning method of a spectrum analyzer as claimed in claim 1, wherein: the display screen in the step S3 is a touch display screen, the input end of the display screen driving module is electrically connected with the output end of the central processing unit, the output end of the display screen driving module is electrically connected with the input end of the display screen of the central processing unit, and the output end of the display screen is electrically connected with the input end of the central processing unit.

4. A spectrum analyzer comprises an analyzer body (1) and a supporting seat (2), and is characterized in that the analyzer body (1) is located above the supporting seat (2), a display screen (3) is arranged on the front side of the analyzer body (1), an operating button (4) is arranged below the front side of the analyzer body (1), an operating knob (5) is arranged on the right side of the front side of the analyzer body (1), two supporting frames (6) are arranged on the upper surface of the supporting seat (2), the analyzer body (1) is rotatably connected between the two supporting frames (6) through a rotating device (7), the rotating device (7) is movably connected with the supporting frames (6) through an adjusting device (8), a limiting device (9) is arranged on the rotating device (7), and adsorption devices (10) are arranged at the four corners of the supporting seat (2), four corners of the supporting seat (2) are provided with placing grooves (11) corresponding to the adsorption devices (10).

5. A spectrum analyzer as defined in claim 4, wherein: two support frame (6) symmetry sets up the left and right sides at supporting seat (2) upper surface, support frame (6) include montant (61) and horizontal pole (62), the bottom of montant (61) is connected with the last fixed surface of supporting seat (2), horizontal pole (62) fixed connection is on the top of montant (61).

6. A spectrum analyzer as defined in claim 4, wherein: rotary device (7) include two pivot (71), connecting block (72) and movable block (73), the one end and the analysis appearance body (1) fixed connection of pivot (71), the other end of pivot (71) passes through bearing and connecting block (72) fixed connection, the right side of movable block (73) fixedly connected with connecting block (72), one of them pivot (71) through connection piece (72) and the first in command of fixedly connected with (74), a plurality of spacing draw-in grooves (75) have evenly been seted up to the surface circumference of pivot (71), two threaded hole (76) and guiding hole (77) have been seted up on movable block (73) respectively.

7. A spectrum analyzer as defined in claim 4, wherein: adjusting device (8) include guide bar (81) and lead screw (82), guide bar (81) and rotary device (7) sliding connection, the one end and support frame (6) fixed connection of guide bar (81), the other end of guide bar (81) is connected with the last fixed surface of supporting seat (2), lead screw (82) and rotary device (7) threaded connection, the upper and lower both ends of lead screw (82) rotate with support frame (6) and supporting seat (2) respectively and are connected, the one end of lead screw (82) is located the outside and the fixedly connected with second handle (83) of support frame (6).

8. A spectrum analyzer as defined in claim 4, wherein: stop device (9) are including install bin (91), the inside sliding connection of install bin (91) has slider (92), the first pull rod (93) of upper surface middle part fixedly connected with of slider (92), the spacing fixture block (94) of lower fixed surface of slider (92), spacing fixture block (94) run through install bin (91) and with rotary device (7) joint, the surface cover of first pull rod (93) is equipped with reset spring (95).

9. A spectrum analyzer as defined in claim 4, wherein: the adsorption device (10) comprises a connecting rod (101), one end of the connecting rod (101) is rotatably connected with the inner wall of the placing groove (11), the other end of the connecting rod (101) is fixedly connected with a first fixing box (102), a cylinder (103) is arranged inside the first fixing box (102) in a penetrating mode, a limiting block (104) is fixed on the outer surface of the cylinder (103) located inside the first fixing box (102), a first spring (105) is sleeved on the outer surface of the cylinder (103), a sucking disc (106) is fixedly connected to the bottom end of the cylinder (103), a second fixing box (107) is fixedly connected to the top end of the cylinder (103), a sealing block (108) is slidably connected inside the second fixing box (107), a second pull rod (109) is fixedly connected to the middle of the upper surface of the sealing block (108), and the top end of the second pull rod (109) is located outside the second fixing box (107), the outer surface of the second pull rod (109) is sleeved with a second spring (1010).

10. A spectrum analyzer as defined in claim 4, wherein: the upper surface fixed connection of supporting seat (2) has protection cushion (12), the upper surface of protection cushion (12) is seted up fluted (1201), recess (1201) and analysis appearance body (1) looks adaptation.

Technical Field

The invention relates to the technical field of analyzers, in particular to a signal scanning method of a spectrum analyzer and the spectrum analyzer.

Background

The analyzer is a common tool used by people for solving the problems of equipment more conveniently and quickly, in particular to a spectrum analyzer. The spectrum analyzer is an instrument for researching the spectrum characteristics of electric signals, is used for measuring signal parameters such as signal distortion degree, modulation degree, spectrum purity, frequency stability, intermodulation distortion and the like, and is an indispensable measuring instrument in the communication electronic industry. However, the technology is continuously developed, and the requirements of people on the spectrum analyzer are higher and higher, so that the traditional spectrum analyzer cannot meet the use requirements of people.

The existing spectrum analyzer is inconvenient to adjust and use, influences a user to check a detection result, cannot meet the current use requirement, is generally placed on a desktop, cannot be stably fixed on the desktop, is easy to move during operation, and brings certain adverse effects to practical use.

Disclosure of Invention

The invention aims to provide a signal scanning method of a spectrum analyzer and the spectrum analyzer, which aim to solve the problems that the prior spectrum analyzer provided in the background art is inconvenient to adjust and use, is easy to move during operation and brings certain adverse effects to practical use.

In order to achieve the purpose, the invention provides the following technical scheme: a method for scanning a signal of a spectrum analyzer, the method comprising the steps of:

s1: preparing a spectrum analyzer, wherein the spectrum analyzer comprises a signal receiving module, a converter, a central processing unit, a display screen control module, a display screen and a storage module, checking whether all connecting cables and connectors of the spectrum analyzer are damaged or not, if the connecting cables and the connectors are damaged, replacing the connecting cables and the connectors into qualified cables and connectors, if the connecting cables and the connectors are not damaged, connecting the qualified cables and connectors to the spectrum analyzer, and then opening the central processing unit;

s2: the signal receiving module scans signals, and then converts the scanned signal data into pulse signal data through a converter;

s3: the pulse signal data are transmitted to the central processing unit through the converter, the central processing unit can control the signal receiving module to stop receiving signals, meanwhile, the central processing unit drives the display screen to display the pulse signals through the display screen control module, the central processing unit can transmit the pulse signal data to the data storage module, and the data storage module can store the pulse signal data.

Preferably, the output end of the signal receiving module is electrically connected with the input end of the converter, the output end of the converter is electrically connected with the input end of the central processing unit, and the output end of the central processing unit is electrically connected with the input end of the signal receiving module.

Preferably, the display screen in step S3 is a touch display screen, the input end of the display screen driving module is electrically connected to the output end of the central processing unit, the output end of the display screen driving module is electrically connected to the input end of the display screen of the central processing unit, and the output end of the display screen is electrically connected to the input end of the central processing unit.

The utility model provides a spectrum analyzer, includes analysis appearance body and supporting seat, the analysis appearance body is located the top of supporting seat, the front of analysis appearance body is provided with the display screen, the front below of analysis appearance body is provided with operating button, the front right side of analysis appearance body is provided with operation knob, the last surface mounting of supporting seat has two support frames, the analysis appearance body passes through rotary device and rotates the connection between two support frames, rotary device passes through adjusting device and support frame swing joint, the last stop device that is provided with of rotary device, adsorption equipment is all installed in the four corners of supporting seat, the standing groove corresponding with adsorption equipment has all been seted up in the four corners of supporting seat.

Preferably, two the support frame symmetry sets up the left and right sides at the supporting seat upper surface, the support frame includes montant and horizontal pole, the bottom of montant and the last fixed surface of supporting seat are connected, horizontal pole fixed connection is on the top of montant.

Preferably, rotary device includes two pivots, connecting block and movable block, the one end and the analysis appearance body fixed connection of pivot, the other end of pivot passes through bearing and connecting block fixed connection, the right side of movable block fixedly connected with connecting block, one of them pivot through connection piece and the first in command of fixedly connected with, a plurality of spacing draw-in grooves have evenly been seted up to the surface circumference of pivot, two threaded hole and guiding hole have been seted up on the movable block respectively.

Preferably, the adjusting device comprises a guide rod and a lead screw, the guide rod is connected with the rotating device in a sliding mode, one end of the guide rod is fixedly connected with the support frame, the other end of the guide rod is fixedly connected with the upper surface of the support seat, the lead screw is connected with the rotating device in a threaded mode, the upper end and the lower end of the lead screw are respectively connected with the support frame and the support seat in a rotating mode, and one end of the lead screw is located outside the support frame and is fixedly connected with a second handle.

Preferably, stop device includes the install bin, the inside sliding connection of install bin has the slider, the first pull rod of upper surface middle part fixedly connected with of slider, the spacing fixture block of lower fixed surface of slider, spacing fixture block run through the install bin and with the rotary device joint, the surface cover of first pull rod is equipped with reset spring.

Preferably, adsorption equipment includes the connecting rod, the one end of connecting rod is connected with the inner wall rotation of standing groove, the first fixed case of other end fixedly connected with of connecting rod, the drum is worn to be equipped with in the inside of first fixed case, the drum is located the inside fixed surface stopper of first fixed incasement, the surface cover of drum is equipped with first spring, the bottom fixedly connected with sucking disc of drum, the top fixedly connected with second fixed case of drum, the inside sliding connection of second fixed case has sealed piece, the upper surface middle part fixedly connected with second pull rod of sealed piece, the top of second pull rod is located the outside of second fixed case, the surface cover of second pull rod is equipped with the second spring.

Preferably, the upper surface of supporting seat is fixedly connected with the protection cushion, the upper surface of protection cushion is seted up flutedly, the recess and the adaptation of analysis appearance body.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, the analyzer body can be rotated to a proper angle through the rotating device, the limit of the rotating shaft can be realized through the matching of the limit clamping block and the limit clamping groove, the rotation of the analyzer body is avoided, and the analyzer body can be lifted through the adjusting device, so that the use is more convenient and the use requirement is met.

2. According to the invention, the adsorption device is rotated out of the placing groove, the limiting block can be driven to move downwards by the restoring force of the first spring, the limiting block can drive the cylinder to move in the moving process, the cylinder can drive the sucker to be in close contact with the tabletop in the moving process, the tabletop is adsorbed more easily, and the phenomenon that the tabletop is easy to move in operation is avoided.

3. According to the invention, the second pull rod is pressed to drive the sealing block to move downwards, the second pull rod can stretch the second spring in the moving process, one end of the cylinder is communicated with the sucker, the other end of the cylinder is communicated with the second fixing box, and the sealing block can move upwards through the restoring force of the second spring, so that the vacuum degree of the sucker is increased, the adsorption stability is ensured, the analyzer body is stably fixed on a desktop, and adverse effects are avoided.

Drawings

FIG. 1 is a block diagram of a spectrum analyzer in accordance with the present invention;

FIG. 2 is a right perspective view of the present invention;

FIG. 3 is a left side perspective view of the present invention;

FIG. 4 is a right side view of the present invention;

FIG. 5 is a schematic view of a rotary apparatus of the present invention;

FIG. 6 is a schematic view of a spacing device of the present invention;

FIG. 7 is a schematic view of an adsorption apparatus of the present invention.

In the figure: 1. an analyzer body; 2. a supporting seat; 3. a display screen; 4. an operation button; 5. an operation knob; 6. a support frame; 7. a rotating device; 8. an adjustment device; 9. a limiting device; 10. an adsorption device; 11. a placement groove; 12. protecting the soft cushion; 1201. a groove; 61. a vertical rod; 62. a cross bar; 71. a rotating shaft; 72. connecting blocks; 73. a movable block; 74. a first handle; 75. a limiting clamping groove; 76. a threaded hole; 77. a guide hole; 81. a guide bar; 82. a screw rod; 83. a second handle; 91. installing a box; 92. a slider; 93. a first pull rod; 94. a limiting clamping block; 95. a return spring; 101. a connecting rod; 102. a first stationary box; 103. a cylinder; 104. a limiting block; 105. a first spring; 106. a suction cup; 107. a second stationary box; 108. a sealing block; 109. a second pull rod; 1010. a second spring.

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.

A method for scanning a signal of a spectrum analyzer, the method comprising the steps of:

s1: preparing a spectrum analyzer, wherein the spectrum analyzer comprises a signal receiving module, a converter, a central processing unit, a display screen control module, a display screen and a storage module, checking whether all connecting cables and connectors of the spectrum analyzer are damaged or not, if the connecting cables and the connectors are damaged, replacing the connecting cables and the connectors into qualified cables and connectors, if the connecting cables and the connectors are not damaged, connecting the qualified cables and connectors to the spectrum analyzer, and then opening the central processing unit;

s2: the signal receiving module scans signals, and then converts the scanned signal data into pulse signal data through a converter;

s3: the pulse signal data are transmitted to the central processing unit through the converter, the central processing unit can control the signal receiving module to stop receiving signals, meanwhile, the central processing unit drives the display screen to display the pulse signals through the display screen control module, the central processing unit can transmit the pulse signal data to the data storage module, and the data storage module can store the pulse signal data.

Furthermore, the output end of the signal receiving module is electrically connected with the input end of the converter, the output end of the converter is electrically connected with the input end of the central processing unit, and the output end of the central processing unit is electrically connected with the input end of the signal receiving module.

Further, the display screen in step S3 is a touch display screen, the input end of the display screen driving module is electrically connected with the output end of the central processing unit, the output end of the display screen driving module is electrically connected with the input end of the display screen of the central processing unit, and the output end of the display screen is electrically connected with the input end of the central processing unit.

Referring to fig. 2-7, a spectrum analyzer, including analysis appearance body 1 and supporting seat 2, analysis appearance body 1 is located the top of supporting seat 2, the front of analysis appearance body 1 is provided with display screen 3, be provided with operating button 4 under the front of analysis appearance body 1, the front right side of analysis appearance body 1 is provided with operation knob 5, the last surface mounting of supporting seat 2 has two support frames 6, analysis appearance body 1 rotates through rotary device 7 to be connected between two support frames 6, rotary device 7 passes through adjusting device 8 and support frame 6 swing joint, be provided with stop device 9 on the rotary device 7, adsorption equipment 10 is all installed in the four corners of supporting seat 2, standing groove 11 corresponding with adsorption equipment 10 is all seted up in the four corners of supporting seat 2.

Further, as shown in fig. 2, two support frames 6 are symmetrically arranged on the left side and the right side of the upper surface of the support base 2, each support frame 6 comprises a vertical rod 61 and a horizontal rod 62, the bottom end of each vertical rod 61 is fixedly connected with the upper surface of the support base 2, and the horizontal rods 62 are fixedly connected to the top ends of the vertical rods 61, so that the support frames 6 are convenient to install the adjusting devices 8, and the analyzer body 1 is convenient to rise.

Further, as shown in fig. 5, the rotating device 7 includes two rotating shafts 71, a connecting block 72 and a movable block 73, one end of the rotating shaft 71 is fixedly connected with the analyzer body 1, the other end of the rotating shaft 71 is fixedly connected with the connecting block 72 through a bearing, the movable block 73 is fixedly connected with the right side of the connecting block 72, one of the rotating shafts 71 penetrates through the connecting block 72 and is fixedly connected with a first handle 74, a plurality of limiting clamping grooves 75 are uniformly formed in the circumference of the outer surface of the rotating shaft 71, threaded holes 76 and guide holes 77 are respectively formed in the two movable blocks 73, the movable block 73 can drive the connecting block 72 to move in the moving process, the connecting block 72 can drive the rotating shaft 71 to move in the moving process, and the rotating shaft 71 can enable the analyzer body 1 to rise in the moving process.

Further, as shown in fig. 3, the adjusting device 8 includes a guide rod 81 and a screw rod 82, the guide rod 81 is slidably connected to the rotating device 7, one end of the guide rod 81 is fixedly connected to the support frame 6, the other end of the guide rod 81 is fixedly connected to the upper surface of the support base 2, the screw rod 82 is in threaded connection with the rotating device 7, the upper end and the lower end of the screw rod 82 are rotatably connected to the support frame 6 and the support base 2, one end of the screw rod 82 is located outside the support frame 6 and is fixedly connected to a second handle 83, the second handle 83 is rotated to drive the screw rod 82 to rotate, and the screw rod 82 can enable the movable block 73 to move axially along the screw rod 82 by being matched with the threaded hole 76 in the rotating process.

Further, as shown in fig. 6, the limiting device 9 includes an installation box 91, the inside sliding connection of the installation box 91 has a slider 92, the middle of the upper surface of the slider 92 is fixedly connected with a first pull rod 93, the lower surface of the slider 92 is fixedly connected with a limiting fixture block 94, the limiting fixture block 94 penetrates through the installation box 91 and is clamped with the rotating device 7, the outer surface of the first pull rod 93 is sleeved with a return spring 95, the first pull rod 93 is pulled to drive the slider 92 to move upwards, the slider 92 can compress the return spring 95 and drive the limiting fixture block 94 to be separated from the limiting fixture groove 75 so as to relieve the limitation on the rotating shaft 71 in the moving process, then the first handle 74 is rotated to rotate the analyzer body 1 to a proper angle, the limiting fixture block 94 is clamped with the limiting fixture groove 75 by the restoring force of the return spring 95, and the rotation of the analyzer body 1 is avoided.

Further, as shown in fig. 7, the adsorption device 10 includes a connecting rod 101, one end of the connecting rod 101 is rotatably connected with the inner wall of the placement groove 11, the other end of the connecting rod 101 is fixedly connected with a first fixing box 102, a cylinder 103 is penetrated inside the first fixing box 102, a limiting block 104 is fixed on the outer surface of the cylinder 103 inside the first fixing box 102, a first spring 105 is sleeved on the outer surface of the cylinder 103, a suction cup 106 is fixedly connected to the bottom end of the cylinder 103, the limiting block 104 can be driven to move downwards by the restoring force of the first spring 105, the limiting block 104 can drive the cylinder 103 to move in the moving process, the suction cup 106 can be driven by the cylinder 103 to be in close contact with the tabletop in the moving process, the tabletop is adsorbed more easily, the easy movement during the operation is avoided, a second fixing box 107 is fixedly connected to the top end of the cylinder 103, a sealing block 108 is slidably connected inside the second fixing box 107, the upper surface middle part fixedly connected with second pull rod 109 of sealed piece 108, the top of second pull rod 109 is located the outside of the fixed case 107 of second, the surface cover of second pull rod 109 is equipped with second spring 1010, press second pull rod 109 to drive sealed piece 108 downstream, second pull rod 109 can stretch second spring 1010 at the in-process that removes, because the one end and the sucking disc 106 intercommunication of drum 103, the other end and the fixed case 107 intercommunication of second of drum 103, restoring force through second spring 1010 can make sealed piece 108 rebound, thereby increase the vacuum assurance absorptive stability of sucking disc 106.

Further, as shown in fig. 2 and 3, the upper surface of the supporting seat 2 is fixedly connected with a protection cushion 12, the upper surface of the protection cushion 12 is provided with a groove 1201, the groove 1201 is matched with the analyzer body 1, the analyzer body 1 is in a vertical state through the rotating device 7 after use, and then the analyzer body is moved into the protection cushion 12 through the adjusting device 8, so that the display screen 3, the operating button 4 and the operating button 5 are protected.

The working principle is as follows: when the adsorption device 10 is used, the adsorption device 10 rotates out of the placing groove 11, the limit block 104 can be driven to move downwards through restoring force of the first spring 105, the limit block 104 can drive the cylinder 103 to move in the moving process, the cylinder 103 can drive the sucker 106 to be in close contact with a desktop in the moving process, the desktop is easier to adsorb, the easy movement in operation is avoided, then the second pull rod 109 is pressed to drive the sealing block 108 to move downwards, the second pull rod 109 can stretch the second spring 1010 in the moving process, because one end of the cylinder 103 is communicated with the sucker 106, the other end of the cylinder 103 is communicated with the second fixing box 107, the sealing block 108 can be driven to move upwards through restoring force of the second spring, so that the vacuum degree of the sucker 106 is increased, the adsorption stability is ensured, the first pull rod 93 is pulled to drive the slider 92 to move upwards, the slider 92 can compress the reset spring 95 and drive the limit fixture block 94 to be separated from the limit fixture block 75 in the moving process, and then the slider 92 is separated so as to be separated from the limit fixture block 75 Except that the spacing of countershaft 71, then rotate first in command 74 and make analysis appearance body 1 rotatory to suitable angle, the restoring force through reset spring 95 makes spacing fixture block 94 and spacing draw-in groove 75 joint, avoid analysis appearance body 1 to appear rotating, then it is rotatory to rotate second handle 83 and drive lead screw 82, lead screw 82 can make the axial displacement of movable block 73 along lead screw 82 through cooperating with screw hole 76 at rotatory in-process, movable block 73 can drive connecting block 72 and remove at the in-process that removes, connecting block 72 can drive pivot 71 and remove at the in-process that removes, pivot 71 can make analysis appearance body 1 rise at the in-process that removes, thereby satisfy the user demand.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.