阅读说明：本技术 高速气流穿通式风冷散热机载天线 (High-speed airflow through type air-cooling heat dissipation airborne antenna ) 是由 彭磊 何林涛 黄文强 于 2021-08-31 设计创作，主要内容包括：本发明公开的一种高速气流穿通式风冷散热机载天线,抗恶劣环境,散热效率高。本发明通过下述技术方案实现：整流罩和天线罩围成一个保护天线本体的封闭空间,整流罩通过载板的外壁环圆滑过渡连接天线罩；载板沿着航向前端设计进风区,通过中间矩形凹腔、后端排风区,将天线本体嵌装在载板的矩形凹腔位置,搭扣在载板的凹腔上表面,形成散热功能区；天线本体嵌入至载板凹腔内设有顺着航向的条形散热齿,天线产生的热传导给自带的散热齿,利用载机在高空飞行过程中产生的风吹气流将热带走,从航向斜前端的左右两侧进风口进入的高速冷空气来流,在进风区后端处汇合后流经散热风道,由排风口排出,空气直接吹过散热齿表面将天线散发的热量排至大气中。(The high-speed airflow through type air-cooling heat dissipation airborne antenna disclosed by the invention is resistant to severe environment and high in heat dissipation efficiency. The invention is realized by the following technical scheme: the radome and the radome enclose a closed space for protecting the antenna body, and the radome is connected with the radome through the outer wall ring of the carrier plate in a smooth transition manner; the antenna body is embedded in the rectangular concave cavity of the carrier plate through the middle rectangular concave cavity and the rear end exhaust area, and the hasp is arranged on the upper surface of the concave cavity of the carrier plate to form a heat dissipation function area; the antenna body is embedded into the cavity of the support plate, strip-shaped heat dissipation teeth along the course are arranged in the cavity, heat generated by the antenna is conducted to the heat dissipation teeth, air blowing flow generated by the carrier in the high-altitude flight process is utilized to take away heat, high-speed cold air entering from air inlets on the left side and the right side of the inclined front end of the course comes and flows through the heat dissipation air duct after being converged at the rear end of the air inlet area, the cold air is discharged from the air outlet, and the air directly blows the surface of the heat dissipation teeth to discharge the heat dissipated by the antenna to the atmosphere.)

1. A high velocity airflow pass-through air-cooled heat dissipating airborne antenna comprising: antenna body (1), enclose into antenna house (2) and radome fairing (4) of protection antenna enclosure space together with aircraft skin, bear carrying (3) of antenna body (1), and distribute in intake zone (201) and locate heating resistor silk (5) and wind speed sensor (6), its component characterized in that: the radome (4) and the radome (2) enclose a closed space for protecting the antenna body (1), and the radome (4) is connected with the radome (2) through the outer wall ring of the carrier plate (3) in a smooth transition mode; an air inlet area (201) is designed at the front end of the carrier plate (3) along the navigation direction, the antenna body (1) is embedded in the rectangular concave cavity of the carrier plate (3) through a rectangular concave cavity designed in the middle and an air exhaust area (202) designed at the rear end, flanges are installed, and buckles are buckled on the upper surface of the concave cavity of the carrier plate (3) to form a heat dissipation function area; the part of the antenna body (1) embedded into the cavity of the carrier plate (3) is provided with a strip-shaped heat dissipation tooth along the course, the radiating teeth are directly designed on the antenna body (1) to enhance the heat exchange on the surface of the antenna, heating components and high-power high-heat-flux functional units in the antenna body (1) are directly attached to a shell where the radiating teeth are located, heat is directly conducted to the radiating teeth, heat generated by the antenna is conducted to the radiating teeth, wind-blown airflow generated by a carrier in the high-altitude flight process is utilized to take away the heat through a radiating functional area, and high-speed cold air entering from air inlets (301) on the left side and the right side of the inclined front end of the heading direction comes, the air flows through the heat dissipation air duct (302) after being converged at the rear end of the air inlet area (201), finally flows through the air exhaust area (202) and is exhausted from the air outlet (303), and the high-speed low-temperature air directly blows over the surface of the heat dissipation teeth to discharge the heat dissipated by the antenna to the outside atmosphere.

2. The high-speed airflow through type air-cooled heat dissipation airborne antenna of claim 1, characterized in that: : the antenna body (1) is rectangular, mounting flanges are designed on the peripheral edges of the antenna body and are buckled on the upper surface of a rectangular concave cavity of the carrier plate (3) to form a closed space, and heat dissipation teeth of the antenna body (1) stretch into the rectangular concave cavity of the carrier plate (3) to form a heat dissipation air duct (302) air duct area.

3. The high-velocity airflow through air-cooled heat dissipating airborne antenna of claim 12, wherein: the front end of the heat dissipation air duct (302) is provided with an air inlet area (201) which is positioned at two sides of the air inlet area (201) facing to the oblique front end, so that foreign matters are prevented from directly entering the heat dissipation air duct (302) in the front of the course during flying; the rear end of the heat dissipation (302) is an exhaust area (202), and hot air after heat exchange is exhausted backwards into the atmosphere through an exhaust outlet 303.

4. The high-speed airflow through type air-cooled heat dissipation airborne antenna of claim 1, characterized in that: controlling the flow direction of the airflow: the air inlet area (201) is in a V-shaped structural form, high-speed air obliquely flows into the air inlet area (201) through the air inlets (301) on two sides, and the flying high-speed airflow is guided to be in a parallel course direction through the V-shaped flow channel of the air inlet area () 201.

5. The high-speed airflow through type air-cooled heat dissipation airborne antenna of claim 4, wherein: the heat dissipation air duct (302) is designed with heat dissipation fins parallel to the course, air flow converged into the direction parallel to the course in the air inlet area (201) directly flows into the heat dissipation air duct (302), continues to flow through the air exhaust area (202) along the direction of the course after heat exchange is completed, and flows out from the air outlet (303).

6. The high-speed airflow through type air-cooled heat dissipation airborne antenna of claim 1, characterized in that: the air inlet (301), the air inlet area (201), the heat dissipation air duct (302), the air exhaust area (202) and the air outlet (303) form a ventilation path parallel to the course direction, and airflow direction control is achieved.

7. The high-speed airflow through type air-cooled heat dissipation airborne antenna of claim 1, characterized in that: based on the whole appearance of the fairing (4), the air inlet (301) is designed into an array round hole, discrete small holes are used for replacing continuous large through holes, large-area stripping of high-speed airflow flowing through the position of the air inlet (301) is avoided, and the whole pneumatic appearance of the machine body is protected.

8. The high-speed airflow through type air-cooled heat dissipation airborne antenna of claim 1, characterized in that: the air inlet area (201) is in a V-shaped structural form, the cross sections of air inlet channels on two sides are rectangular, spiral grooves are formed in the outer wall surfaces of the air inlet channels, the heating resistance wire ()5 is fixed on the wall surfaces of the air inlet channels through welding, the air speed sensor (6) is installed in the air inlet channels (301), and the air speed in the air inlet channels is monitored in real time and transmitted to the antenna unit.

9. The high-speed airflow through type air-cooled heat dissipation airborne antenna of claim 1, characterized in that: the antenna unit is combined with flight data of the aerial carrier to judge the flight state of the aerial carrier, and then whether the air inlet (301) generates the phenomenon of ice blockage is judged, and a heating resistance wire ()5 is started to heat the air inlet area () 201.

10. The high-speed airflow through air-cooled heat dissipating airborne antenna of claim 9, wherein: the thermal resistance wire (5) is welded on the wall surface of the air inlet channel, the air speed sensor (6) monitors the air speed in real time, and the antenna unit judges the deicing operation in real time.

Technical Field

The invention belongs to the field of heat dissipation of avionic devices, and particularly relates to a flow monitoring and deicing device for an air cooling heat dissipation flow channel and an air inlet of an airborne antenna.

Background

The chip of the T/R component is a main heating device of the phased array antenna array surface and is also a main object of temperature control. The T/R component is used as a main heat source of an active phased array antenna array surface, and the maximum temperature and temperature uniformity control of the T/R component is the core content of the active phased array antenna thermal design. Wavefront temperature control is one of the key technologies for phased array antenna structure design. Due to the fact that a plurality of T/R components are arranged inside the antenna, the arrangement is compact, the heat dissipation space is small, the heat flow density of the antenna is large, if the heat cannot be taken away from the antenna array surface in time, the temperature of the antenna is increased, the performance of the T/R components is reduced and even fails, and the performance of the antenna is affected, and the performance of the antenna is deteriorated. The thermal design of an active phased array antenna is therefore directly related to the electrical performance specifications of the antenna. The difficulty of the heat dissipation design of the T/R component mainly comes from two aspects, namely strict temperature control requirement. The phased array antenna has strict phase requirements on electromagnetic wave signals, and the performance of the T/R component is easily influenced by temperature, so the strict requirements are put on the working temperature of the T/R component; secondly, the heat dissipation environment is severe. The T/R assembly not only has large heating power, but also has hundreds of numbers, compact structure and poor heat dissipation condition. The harsh temperature control requirements and harsh heat dissipation environments place extremely high demands on the structural design. Generally, a T/R assembly cooling system structure adopts a forced air cooling mode to cool an antenna array surface, and the cooling system consists of a fan, a ventilation pipeline, an array surface outer flow channel and an array surface inner flow channel. The fan is used for generating fluid with wind speed and wind pressure meeting design requirements; the array surface outer channel conveys cooling gas to the antenna array surface; the flow guide pipe is used for realizing transition of the array surface outer flow passage and the array surface inner flow passage; the flow channels in the array surface are naturally formed by the T/R components which are arranged in order. When the phased array antenna cooling system works, heat emitted by the T/R component chip is transferred to the radiating fins through the aluminum heat conducting plate, and when fluid flows through the flow channel in the array surface, the heat of the radiating fins is taken away, so that the heat of the chip is radiated. Due to the ever-increasing heat flux density of the antenna front and the high reliability requirements, the cooling technology also faces great challenges. In order to adapt to various severe working environments, the array surface requires structural sealing design; due to the narrow space between the units, the heat dissipation requirements cannot be met by adopting direct liquid cooling and natural ventilation. Therefore, forced circulation closed air cooling must be adopted to dissipate heat of the array. Although the existing thermal design of the active phased-array antenna can adopt forced air cooling, forced liquid cooling or high-efficiency heat pipe technology and the like according to the heat flux density of an antenna array surface and the using environment of the antenna, the normal work of heating components such as components and the like is ensured. But a circulating air duct, heat exchange equipment and a fan are reasonably arranged in a narrow and light array surface, so that the heat dissipation of the array surface, the temperature uniformity and the like are realized. Such requirements present a significant challenge to the array heat dissipation design.

According to the functional requirements of a certain type of airplane, a certain type of active phased array antenna needs to be installed on the surface of the airplane. The antenna is installed in a space enclosed by the antenna cover, the fairing and the aircraft skin. Because the working power of the antenna is high, and the installation position of the antenna is positioned on the surface of the airplane, the airplane cannot provide an environmental control system or a heat sink, and therefore the antenna can only be designed by utilizing natural air cooling. In order to ensure that the antenna can stably and reliably work for a long time in the all-weather flight process of the aircraft, the design of an air-cooling heat dissipation channel needs to be developed in a targeted manner, so that the high reliability of the antenna is ensured, and the capability of the antenna for resisting the severe environment is improved. The conventional air-cooled radiating scheme of the meter antenna generally adopts two schemes of fan radiating and directly introducing external flying high-speed airflow radiating.

The heat dissipation scheme of directly introducing external flying high-speed airflow is that an air inlet is formed at the front end of a fairing or an antenna cover, and an air outlet is formed at the tail end of the fairing. In the flying process of the carrier, the air inlet at the front end of the antenna introduces outside high-speed incoming cold air, and the cold air takes away heat when flowing through the surface of the antenna and is exhausted from the air outlet at the tail end. According to the heat dissipation scheme, an air inlet is formed in the front end of the antenna, high-speed airflow directly blows through the antenna, and the requirement on protection of the antenna is high; meanwhile, when high-speed airflow flows through the air inlet, the boundary layer of the airflow is separated, negative influence is caused on the aerodynamic characteristics of the carrier, and in addition, under the high-speed high-altitude and high-cold flight conditions, the air inlet has the risk of condensation and icing, so that higher requirements are provided for the design of the air inlet.

The fan heat dissipation scheme is that a fan is adopted to directly blow the surface of the antenna to realize heat exchange of a heat dissipation wall surface, heat conducted to the surface of the antenna is transferred to air in the antenna housing through forced natural convection generated by the fan, and meanwhile, ventilation holes are formed in the side wall of the fairing or the antenna housing so that hot air in the housing and outside cold air can be exchanged, and heat loss is diffused into the atmosphere. The scheme requires that the fan works in a ground environment and a severe high-altitude flying environment, has high requirements on the environmental adaptability and reliability of the fan, and simultaneously has the disadvantages that the air is thin in the high-altitude flying process, the heat dissipation capacity of the fan is rapidly reduced, and the heat control requirement of the high-power and high-heat-flow-density active phased array antenna provides a more severe challenge for the heat dissipation efficiency of the fan.

Disclosure of Invention

The air-cooled heat dissipation airborne antenna scheme has the advantages that the adverse environment resistance is provided, the heat dissipation efficiency is high, the heat dissipation performance can be improved, and the good environment adaptability heat dissipation is realized.

The above object of the present invention can be achieved by the following means: a high velocity airflow pass-through air-cooled heat dissipating airborne antenna comprising: antenna body 1, enclose into protection antenna enclosure space's antenna house 2 and radome fairing 4 together with aircraft skin, bear antenna body 1's support plate 3, and distribute in 201 department's heating resistor silk 5 of intake zone and wind speed sensor 6, its component characterized in that: the radome 4 and the radome 2 enclose a closed space for protecting the antenna body 1, and the radome 4 is connected with the radome 2 through the outer wall ring of the carrier plate 3 in a smooth transition mode; an air inlet area 201 is designed at the front end of the carrier plate 3 along the navigation direction, the antenna body 1 is embedded in the rectangular concave cavity of the carrier plate 3 through a rectangular concave cavity designed in the middle and an air exhaust area 202 designed at the rear end, flanges are installed, and buckles are buckled on the upper surface of the concave cavity of the carrier plate 3 to form a heat dissipation function area; the part of the antenna body 1 embedded into the cavity of the carrier plate 3 is designed with a strip-shaped heat dissipation tooth along the course, the heat dissipation tooth is directly designed on the antenna body 1, the heat exchange on the surface of the antenna is enhanced, a heating component and a high-power high-heat-flux functional unit in the body 1 are directly attached to a shell where the heat dissipation tooth is located, the heat is directly conducted to the heat dissipation tooth, the heat generated by the antenna is conducted to the heat dissipation tooth, the air blowing airflow generated by the carrier in the high-altitude flight process is utilized to take away the heat through a heat dissipation functional area, the high-speed cold air incoming from the air inlets 301 on the left side and the right side of the inclined front end of the course flows through the heat dissipation air duct 302 after converging at the rear end of the air inlet area 201, finally flows through the air exhaust area 202 and is exhausted through the air outlet 303, and the high-speed low-temperature air directly blows through the surface of the heat dissipation tooth to exhaust the outside atmosphere.

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

and the device is resistant to severe environment. According to the invention, a closed space for protecting an antenna body 1 is enclosed by a fairing 4 and an antenna housing 2, and the wind heat dissipation fairing 4 is connected with the antenna housing 2 through the outer wall ring of a carrier plate 3 in a smooth transition manner; the structure for ventilating and radiating by adopting the closed air cooling mode has higher capability of resisting severe environment, can meet the requirement of the working environment of equipment and has good environmental adaptability.

The heat dissipation efficiency is high. According to the invention, the radiating teeth which increase the heat exchange area and improve the radiating efficiency are directly designed on the antenna body 1, the heating component and the high-power high-heat-flow-density functional unit in the antenna body 1 are directly attached to the shell where the radiating teeth are located, the heat is directly conducted to the radiating teeth, so that the heat of the antenna body 1 can be efficiently dispersed and transferred to the radiating teeth, and then high-speed cold air is introduced to directly blow the surface of the radiating teeth, thus the radiating device has the advantages of short radiating path, small thermal resistance and high thermal conductivity, and the defect that the radiating defects cannot be met by adopting direct liquid cooling and natural ventilation due to narrow space among the antenna units is solved.

The reliability of the antenna is improved. According to the invention, the antenna body 1 is embedded in the rectangular concave cavity of the carrier plate 3, the flange is installed, the hasp is arranged on the upper surface of the concave cavity of the carrier plate 3 to form a heat dissipation function area, the air inlet 301 is designed at the inclined front ends of the left side and the right side of the course direction of the antenna, and foreign matters in the front of the course direction can be prevented from directly entering the heat dissipation function area to damage the antenna during flying. This encapsulates the heat sink functional area in the rectangular cavity of the carrier plate 3; the heat generated by the antenna is conducted to the self-contained heat dissipation teeth, the heat is taken away by blowing the heat dissipation functional area, and the antenna body is not exposed in external high-speed airflow except the heat dissipation teeth and is not directly facing to the external severe natural environment, so that the reliability of the antenna is improved.

The reliability of the heat dissipation system is improved. According to the invention, the antenna body 1 is embedded into the cavity of the carrier plate 3, the radiating teeth are directly designed on the antenna body 1 by designing the strip-shaped radiating teeth along the course, the heat exchange on the surface of the antenna is enhanced, the heating element and the high-power high-heat-flux functional unit in the body 1 are directly attached to the shell where the radiating teeth are located, the heat is directly conducted to the radiating teeth, the heat generated by the antenna is conducted to the radiating teeth, and the wind-blown airflow generated by the carrier during the high-altitude flight process is utilized to take away the heat through the radiating functional area, so that the smoothness of a radiating channel is ensured, and the reliability of a radiating system is improved. The technical scheme has no electronic component, and a fan heat dissipation scheme with high-altitude heat dissipation efficiency and large loss is abandoned.

The influence of the air inlet 301 on the pneumatic appearance of the carrier is reduced. The invention adopts the air inlet 301 and the air outlet 303 which are respectively designed, high-speed cold air is directly introduced from the outside of the airplane to be used as a heat dissipation passage in heat dissipation, the air inlet 301 is designed based on the shape of the fairing 4, an array circular hole is designed, a large number of uniform discrete small holes are adopted to replace continuous large through holes, large-area stripping of high-speed airflow flowing through the position of the air inlet 301 is avoided, the integral pneumatic shape of the airplane body is protected, and the influence of the air inlet 301 on the pneumatic characteristic of the airplane is reduced.

Drawings

FIG. 1 is a schematic cross-sectional view of a high-speed air-cooled airflow heat-dissipating airborne antenna according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view in the extension direction of fig. 1.

FIG. 3 is a schematic view of the construction with the skin removed.

Fig. 4 is a top view of fig. 3.

In the figure: 1-an antenna body, 2-an antenna housing, 3-a carrier plate, 4-a fairing, 5-a heating resistance wire, 6-an air speed sensor, 201-an air inlet area, 202-an air exhaust area, 301-an air inlet, 302-a heat dissipation air duct and 303-an air outlet.

Detailed Description

See fig. 1-4. In a preferred embodiment described below, a high-speed air-cooled airflow heat dissipating airborne antenna comprises: antenna body 1, enclose into protection antenna enclosure space's antenna house 2 and radome fairing 4 together with aircraft skin, bear antenna body 1's support plate 3, and distribute in 201 department's heating resistor silk 5 of intake zone and wind speed sensor 6, its component characterized in that: the radome 4 and the radome 2 enclose a closed space for protecting the antenna body 1, and the radome 4 is connected with the radome 2 through the outer wall ring of the carrier plate 3 in a smooth transition mode; an air inlet area 201 is designed at the front end of the carrier plate 3 along the navigation direction, the antenna body 1 is embedded in the rectangular concave cavity of the carrier plate 3 through a rectangular concave cavity designed in the middle and an air exhaust area 202 designed at the rear end, flanges are installed, and buckles are buckled on the upper surface of the concave cavity of the carrier plate 3 to form a heat dissipation function area; the part of the antenna body 1 embedded into the cavity of the carrier plate 3 is designed with a strip-shaped heat dissipation tooth along the course, the heat dissipation tooth is directly designed on the antenna body 1, the heat exchange on the surface of the antenna is enhanced, a heating component and a high-power high-heat-flux functional unit in the body 1 are directly attached to a shell where the heat dissipation tooth is located, the heat is directly conducted to the heat dissipation tooth, the heat generated by the antenna is conducted to the heat dissipation tooth, the air blowing airflow generated by the carrier in the high-altitude flight process is utilized to take away the heat through a heat dissipation functional area, the high-speed cold air incoming from the air inlets 301 on the left side and the right side of the inclined front end of the course flows through the heat dissipation air duct 302 after converging at the rear end of the air inlet area 201, finally flows through the air exhaust area 202 and is exhausted through the air outlet 303, and the high-speed low-temperature air directly blows through the surface of the heat dissipation tooth to exhaust the outside atmosphere. The air inlet area 201 is designed to be a rectangular channel, a heating resistance wire 5 is welded on the wall surface of the air inlet channel, and an air speed sensor 6 is arranged in the air inlet channel; when the phenomenon of icing appears in air intake 301 and causes inlet air duct to block under the high and cold high wet flight environment, the antenna combines wind speed sensor 6 to record the flight data of data and year machine, judges the flight state of year machine, and then judges whether air intake 301 produces the phenomenon of icing now, starts heating resistor wire 5 and heats deicing operation to inlet air duct, ensures radiating passage's unobstructed, has improved cooling system's reliability.

See fig. 4. Air duct area formation: the antenna body 1 is rectangular, mounting flanges are designed on the peripheral edges of the antenna body 1 and are buckled on the upper surface of a rectangular concave cavity of the carrier plate 3 to form a closed space, and heat dissipation teeth of the antenna body 1 extend into the rectangular concave cavity of the carrier plate 3 to form a heat dissipation air duct 302 air duct area; the front end of the heat dissipation air duct 302 is an air inlet area 201, and the heat dissipation air duct is designed to be positioned on two sides of the inclined front end of the course of the air inlet area 201, so that foreign matters in the direct front of the course are prevented from directly entering the heat dissipation air duct 302 during flying; the rear end of the heat dissipation air duct 302 is an exhaust area 202, and hot air after heat exchange is exhausted backwards into the atmosphere through an exhaust port 303.

Refer to fig. 1 and 3. Controlling the flow direction of the airflow: the air inlet area 201 is in a V-shaped structural form, high-speed air obliquely flows into the air inlet area 201 through the air inlets 301 on two sides, and the flying high-speed airflow is guided to be parallel to the course direction through the V-shaped flow channel of the air inlet area 201. The heat dissipation air duct 302 is designed with heat dissipation fins parallel to the heading, so that the air flow merged into the heading parallel direction in the air inlet area 201 directly flows into the heat dissipation air duct 302, continues to flow through the air exhaust area 202 along the heading direction after heat exchange is completed, and flows out from the air outlet 303. The air inlet 301, the air inlet area 201, the heat dissipation air duct 302, the air exhaust area 202 and the air outlet 303 form a ventilation path parallel to the course direction, so that the airflow direction control is realized.

See fig. 3. Designing an air inlet: based on the overall shape of the fairing 4, the air inlet 301 is designed as an array circular hole, and a large number of uniform discrete small holes are adopted to replace continuous large through holes, so that large-area stripping of high-speed airflow flowing through the position of the air inlet 301 is avoided, and the overall aerodynamic shape of the machine body is protected.

: see fig. 4. Airflow monitoring and deicing control: the air inlet area 201 is in a V-shaped structural form, the sections of air inlet channels on two sides are designed to be rectangular, spiral grooves are designed and processed on the outer wall surface of the air inlet channels, the heating resistance wires 5 are fixed on the wall surface of the air inlet channels through welding, the air speed sensor 6 is installed in the air inlet channels of the air inlet 301, and the air speed in the air inlet channels is monitored in real time and transmitted to the antenna unit; the antenna unit is combined with flight data of the aerial carrier to judge the flight state of the aerial carrier, further judge whether the air inlet 301 generates the phenomenon of ice formation and blockage, and start the heating resistance wire 5 to heat the air inlet area 201, and as the heating resistance wire 5 is welded on the wall surface of the air inlet channel, the heat transfer resistance is small, and the heating speed is high; the wind speed sensor 6 monitors the wind speed in real time, the antenna unit judges the deicing operation in real time, the response is fast, and the risk of heat dissipation failure is reduced.

The foregoing is directed to the preferred embodiment of the present invention and it is noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.