阅读说明：本技术 电动工具及其电池包安装机构 (Electric tool and battery pack mounting mechanism thereof ) 是由 刘强 于 2021-03-24 设计创作，主要内容包括：本申请提供一种电动工具及其电池包安装机构,电池包安装机构包括壳体及由壳体形成的滑动空间,滑动空间沿第一方向延伸,壳体具有第一端和第二端；滑动空间贯穿第一端,允许电池包沿第一方向安装至壳体并保持在第一终点位置,电池包安装机构配置为使电池包在第二方向上突出第一端的尺寸为d1；滑动空间还贯穿第二端,允许电池包沿第二方向安装至壳体并保持在第二终点位置,电池包安装机构配置为使电池包在第二方向突出第一端的尺寸为d2；d1大于d2,第二方向与第一方向相反。由于电池包能够实现双向插接,使得电池包乃至电动工具的外轮廓能够适当调节,使电动工具能够适用于狭窄空间；此外,双向插接也有利于简化电池包的安装过程,提升用户体验。(The application provides an electric tool and a battery pack mounting mechanism thereof, wherein the battery pack mounting mechanism comprises a shell and a sliding space formed by the shell, the sliding space extends along a first direction, and the shell is provided with a first end and a second end; a sliding space extending through the first end for allowing the battery pack to be mounted to the housing in the first direction and held at a first end position, the battery pack mounting mechanism being configured such that the battery pack protrudes from the first end in the second direction by a dimension d 1; the sliding space further extends through the second end, allowing the battery pack to be mounted to the housing in the second direction and held at a second end position, the battery pack mounting mechanism being configured such that the battery pack protrudes beyond the first end in the second direction by a dimension d 2; d1 is greater than d2 and the second direction is opposite the first direction. The battery pack can realize bidirectional insertion, so that the outer contour of the battery pack and even the outer contour of the electric tool can be properly adjusted, and the electric tool can be suitable for narrow spaces; in addition, the bidirectional insertion is also beneficial to simplifying the installation process of the battery pack, and the user experience is improved.)

1. A battery pack mounting mechanism of an electric power tool, characterized in that the battery pack mounting mechanism comprises a housing and a sliding space formed by the housing, the sliding space extending in a first direction, the housing having a first end and a second end arranged in the first direction;

the sliding space extends through the first end, allowing the battery pack to be mounted to the housing in the first direction and held at a first end position, the battery pack mounting mechanism being configured such that the battery pack protrudes beyond the first end in a second direction by a dimension d 1;

the sliding space further extends through the second end, allowing the battery pack to be mounted to the housing in a second direction and held in a second end position, the battery pack mounting mechanism being configured such that the battery pack protrudes beyond the first end in the second direction by a dimension d 2;

wherein d1 is greater than d2, the second direction being opposite the first direction.

2. The battery pack mounting mechanism as claimed in claim 1, wherein the housing is provided with a first locking portion and a second locking portion;

the first locking portion is configured to limit the battery pack mounted in the first direction to the first end position, and the second locking portion is configured to limit the battery pack mounted in the second direction to the second end position.

3. An electric power tool comprising a tool main body including the battery pack mounting mechanism of claim 1 or 2, and a battery pack configured to be mounted to the housing in the first or second direction for supplying power to the tool main body.

4. The power tool of claim 3, wherein the sliding space includes a docking space and a guide groove communicating with the docking space, the guide groove being parallel to the first direction;

the tool body comprises a first terminal set and a second terminal set, the first terminal set and the second terminal set are exposed in the butt joint space and are arranged in a manner of being centrosymmetric relative to the center of the butt joint space, the battery pack is electrically connected with the first terminal set when being installed in the shell along the first direction, and the battery pack is electrically connected with the second terminal set when being installed in the shell along the second direction;

the first terminal group comprises a first positive terminal and a first negative terminal, the second terminal group comprises a second positive terminal and a second negative terminal, the first positive terminal is electrically connected with the second positive terminal, and the first negative terminal is electrically connected with the second negative terminal.

5. The power tool of claim 4, wherein the battery pack includes a third terminal set and a cavity, the third terminal set and the cavity being aligned in a mounting direction of the battery pack;

when the battery pack is mounted to the housing in the first direction, the third terminal set is mated with the first terminal set, and the second terminal set is located within the cavity; when the battery pack is mounted on the shell along the second direction, the third terminal set is connected with the second terminal set, and the first terminal set is located in the cavity.

6. The power tool of claim 4, wherein the housing has a first set of recesses and a second set of recesses undercut from the docking space, an orthographic projection of the first terminal set on the housing being within the first set of recesses, and an orthographic projection of the second terminal set on the housing being within the second set of recesses;

when the battery pack is installed to the shell along the first direction, the battery pack pushes the second terminal group into the second groove group; when the battery pack is installed to the shell along the second direction, the battery pack pushes the first terminal group into the first groove group.

7. The power tool of claim 3, wherein the battery pack mounting mechanism includes a first stop and a second stop, the battery pack including a first end surface and a second end surface aligned in the mounting direction thereof, the first stop being movably mounted to the first end of the housing, the second stop being movably mounted to the second end of the housing;

when the battery pack is mounted to the shell along the first direction, the first baffle is pressed by the battery pack and is positioned between the battery pack and the shell, and the second baffle covers the second end face of the battery pack; when the battery pack is mounted to the shell along the second direction, the second baffle is pressed by the battery pack and is located between the battery pack and the shell, and the first baffle covers the second end face of the battery pack.

8. The power tool of claim 7, wherein the first stop is rotatably mounted to a first end of the housing and the second stop is rotatably mounted to a second end of the housing;

the battery pack mounting mechanism further comprises a first reset element and a second reset element, the first reset element is configured to drive the first baffle to return to the initial position from the position pressed by the battery pack, and the second reset element is configured to drive the second baffle to return to the initial position from the position pressed by the battery pack.

9. The power tool of claim 3, wherein when a battery pack is mounted to the housing in the first direction, a center of gravity of the battery pack is located at a first position;

when a battery pack is mounted to the housing in the second direction, the center of gravity of the battery pack is located at a second position;

the second position is no less than 10mm from the first position.

10. The power tool according to claim 3, wherein the tool main body includes a motor and an output shaft driven by the motor, the output shaft extending in an up-down direction;

when the battery pack is assembled to the shell from the first direction, the battery pack is higher than the lower end face of the tool main body;

when the battery pack is assembled to the housing from the second direction, the battery pack is lower than the upper end surface of the tool main body.

Technical Field

The application relates to the field of electric tools, in particular to an electric tool and a battery pack mounting mechanism thereof.

Background

Compared with a manual tool, the electric tool has the advantages of high efficiency, high precision and the like. The lithium battery tool adopts the lithium battery as a power supply, is not restricted by cables any more and has wider application scenes. Fig. 1 shows an angle grinder which is powered by a battery pack a mounted to a tool body B from top to bottom, and the upper end of the battery pack a protrudes from the upper end surface S of the tool body B, and in the scenario shown in fig. 1, the space above the angle grinder is limited, and it is difficult to perform grinding work in this scenario.

Disclosure of Invention

The application provides an electric tool capable of realizing a narrow space and a battery pack mounting mechanism thereof.

Specifically, the present application provides a battery pack mounting mechanism of an electric power tool, the battery pack mounting mechanism including a housing and a sliding space formed by the housing, the sliding space extending in a first direction, the housing having a first end and a second end arranged in the first direction; the sliding space extends through the first end, allowing the battery pack to be mounted to the housing in the first direction and held at a first end position, the battery pack mounting mechanism being configured such that the battery pack protrudes beyond the first end in a second direction by a dimension d 1; the sliding space further extends through the second end, allowing the battery pack to be mounted to the housing in a second direction and held in a second end position, the battery pack mounting mechanism being configured such that the battery pack protrudes beyond the first end in the second direction by a dimension d 2; wherein d1 is greater than d2, the second direction being opposite the first direction.

Furthermore, the shell is provided with a first locking part and a second locking part; the first locking portion is configured to limit the battery pack mounted in the first direction to the first end position, and the second locking portion is configured to limit the battery pack mounted in the second direction to the second end position.

In another aspect, the present application further provides an electric tool, which includes a tool main body and a battery pack, wherein the tool main body includes the battery pack mounting mechanism as described above, and the battery pack is configured to be mounted on the housing along the first direction or the second direction to supply power to the tool main body.

Further, the sliding space comprises a docking space and a guide groove communicated with the docking space, and the guide groove is parallel to the first direction; the tool body comprises a first terminal set and a second terminal set, the first terminal set and the second terminal set are exposed in the butt joint space and are arranged in a manner of being centrosymmetric relative to the center of the butt joint space, the battery pack is electrically connected with the first terminal set when being installed in the shell along the first direction, and the battery pack is electrically connected with the second terminal set when being installed in the shell along the second direction; the first terminal group comprises a first positive terminal and a first negative terminal, the second terminal group comprises a second positive terminal and a second negative terminal, the first positive terminal is electrically connected with the second positive terminal, and the first negative terminal is electrically connected with the second negative terminal.

Further, the battery pack comprises a third terminal set and a cavity, and the third terminal set and the cavity are arranged along the installation direction of the battery pack; when the battery pack is mounted to the housing in the first direction, the third terminal set is mated with the first terminal set, and the second terminal set is located within the cavity; when the battery pack is mounted on the shell along the second direction, the third terminal set is connected with the second terminal set, and the first terminal set is located in the cavity.

Further, the housing has a first groove set and a second groove set formed by sinking from the butting space, an orthographic projection of the first terminal set on the housing is positioned in the first groove set, and an orthographic projection of the second terminal set on the housing is positioned in the second groove set; when the battery pack is installed to the shell along the first direction, the battery pack pushes the second terminal group into the second groove group; when the battery pack is installed to the shell along the second direction, the battery pack pushes the first terminal group into the first groove group.

Further, the battery pack mounting mechanism comprises a first baffle and a second baffle, the battery comprises a first end surface and a second end surface which are arranged along the mounting direction of the battery, the first baffle is movably mounted at the first end of the shell, and the second baffle is movably mounted at the second end of the shell; when the battery pack is installed on the shell along the first direction, the first baffle is pressed by the battery pack and is positioned between the battery pack and the shell, and the second baffle covers the second end face of the battery pack; when the battery pack is installed on the shell along the second direction, the second baffle is pressed by the battery pack and is located between the battery pack and the shell, and the first baffle covers the second end face of the battery pack.

Further, the first baffle plate is rotatably mounted at the first end of the shell, and the second baffle plate is rotatably mounted at the second end of the shell; the battery pack mounting mechanism further comprises a first reset element and a second reset element, the first reset element is configured to drive the first baffle to return to the initial position from the position pressed by the battery pack, and the second reset element is configured to drive the second baffle to return to the initial position from the position pressed by the battery pack.

Further, when the battery pack is mounted to the housing in a first direction, the center of gravity of the battery pack is located at a first position; when the battery pack is mounted to the housing in a second direction, the center of gravity of the battery pack is located at a second position; the second position is no less than 10mm from the first position.

Further, the tool main body comprises a motor and an output shaft driven by the motor, and the output shaft extends along the vertical direction; when the battery pack is assembled to the shell from the first direction, the battery pack is higher than the lower end face of the tool main body; when the battery pack is assembled to the housing from the second direction, the battery pack is lower than the upper end surface of the tool main body.

In the application, the battery pack can be inserted in two directions, so that the outer contour of the battery pack and even the outer contour of the electric tool can be properly adjusted, the battery pack is prevented from interfering with the surrounding environment in a narrow space to influence the operation of a user, and the electric tool can be suitable for the narrow space; in addition, the bidirectional insertion is also beneficial to simplifying the installation process of the battery pack, and the user experience is improved.

Drawings

Fig. 1 is a schematic structural view of a conventional power tool in a narrow space.

Fig. 2 is a perspective view of an embodiment of the power tool of the present application.

Fig. 3 is a perspective view of the battery pack mounting mechanism of the electric power tool shown in fig. 2.

Fig. 4 is a perspective view of a battery pack of the electric power tool shown in fig. 2.

Fig. 5 is a schematic front view of the power tool shown in fig. 2, wherein the battery pack is mounted in a first direction.

Fig. 6 is a schematic front view of the power tool shown in fig. 2, wherein the battery pack is mounted in a second orientation.

Fig. 7 is a schematic front view of a battery pack mounting mechanism according to another embodiment of the present application.

Fig. 8 and 9 are schematic front views of a power tool according to another embodiment of the present application, in which battery packs are mounted in opposite directions, respectively.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. As used in this application, the terms "first," "second," and the like do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. "plurality" or "a number" means two or more. Unless otherwise indicated, "front", "rear", "lower" and/or "upper" and the like are for convenience of description and are not limited to one position or one spatial orientation. The word "comprising" or "comprises", and the like, means that the element or item listed as preceding "comprising" or "includes" covers the element or item listed as following "comprising" or "includes" and its equivalents, and does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

The application provides a battery pack mounting mechanism of an electric tool, the battery pack mounting mechanism comprises a shell and a sliding space formed by the shell, the sliding space extends along a first direction, and the shell is provided with a first end and a second end which are arranged along the first direction; the sliding space extends through the first end, allowing the battery pack to be mounted to the housing in the first direction and held at a first end position, the battery pack mounting mechanism being configured such that the battery pack protrudes beyond the first end in a second direction by a dimension d 1; the sliding space further extends through the second end and is maintained at a second end position, allowing the battery pack to be mounted to the housing in a second direction, the battery pack mounting mechanism being configured such that the battery pack protrudes beyond the first end in the second direction by a dimension d 2; wherein d1 is greater than d2, the second direction being opposite the first direction.

Referring to fig. 2, the electric power tool of the present embodiment is, for example, an angle grinder, and includes a tool body 1 and a battery pack 2 mounted to the tool body 1, where the battery pack 2 is used for supplying power to the tool body 1 to drive a working head 3 to work. The tool main body 1 comprises a shell 11, a motor (not shown) arranged in the shell 11, a transmission mechanism 12 connected with a motor shaft, and an output shaft 13 connected with the transmission mechanism 12, wherein the transmission mechanism 12 is used for transmitting the power of the motor to the output shaft 13 so as to drive a working head 3 mounted on the output shaft 13 to work.

Referring to fig. 3 to 5, the rear end portion of the housing 11 serves as the housing 41 of the battery pack mounting mechanism 4, and the portion of the housing connected to the housing forms a grip portion 110 for a user to grip. The housing 41 encloses a sliding space 40, and the sliding space 40 extends along a first direction X +. The sliding space 40 penetrates the first and second ends 411 and 412 of the housing 41, and the first and second ends 411 and 412 are arranged in a first direction X +, thereby allowing the battery pack 2 to be mounted in the first and second directions X + and X-respectively, which are opposite to each other, as will be readily understood. Specifically, the sliding space 40 includes a docking space 401 and a sliding groove 402 communicating with the docking space 401. The battery pack mounting mechanism 4 further includes a first terminal set 42 and a second terminal set 43, and the first terminal set 42 and the second terminal set 43 are exposed in the docking space for docking with the battery pack 2. In order to ensure that the battery pack can be electrically connected from two directions by plugging, the first terminal set 42 and the second terminal set 43 are centrosymmetric with respect to the geometric center of the docking space 401. It should be noted that the central symmetry here only indicates that the positions of the first terminal set 42 and the second terminal set 43 are central symmetry, and it is not necessary that the shapes and sizes of the two are completely consistent.

When the battery pack 2 is assembled to the housing 41 in the first direction X +, the battery pack 2 protrudes from the first end 411 in the second direction X-by a dimension d1 (fig. 4); when the battery pack 2 is assembled to the case 41 in the second direction X-, the battery pack 2 protrudes from the first end 411 in the second direction X-by a dimension d2 (d 2 is 0 in fig. 5), wherein d1 is greater than d 2. It is noted that when the battery pack 2 does not actually protrude the first end 411 in the second direction X-it is understood that d2 is equal to 0. That is, when the space of the power tool in the second direction X-is limited (which may be understood approximately as an obliquely upper area of the power tool), it is possible to select to mount the battery pack from the second direction X-so as to enable the user to work normally, as shown in fig. 4. The battery pack can be installed from the first direction X + when the space of the power tool in the first direction X + (which can be understood approximately as the obliquely lower region of the power tool) is limited. In fact, since the non-mounting end 22 of the battery pack is large in size, the non-mounting end 22 protrudes to some extent from the end of the case 41 regardless of the direction from which the battery pack is mounted, and the present application also solves the problem of insufficient space by adjusting the position of the non-mounting end 22.

Preferably, the output shaft 13 extends in the up-down direction (when the holding manner is changed, the up-down direction is also changed). Preferably, when the battery pack 2 is assembled to the housing 41 from the first direction X +, the battery pack 2 is higher than the lower end surface of the tool main body 1; when the battery pack 2 is assembled to the housing 41 from the second direction X-, the battery pack 2 is lower than the upper end surface of the tool main body 1. By changing the installation direction of the battery pack 2, the electric tool can be adapted to different narrow spaces, such as the scenarios simulated in fig. 4 and 5.

Referring to fig. 3 and 6, in order to limit the battery pack to the corresponding end position, the battery pack mounting mechanism further includes a first locking portion 441 and a second locking portion 442. The first locking portion 441 is configured to limit the battery pack 2 mounted in the first direction X + to a first end position, and the second locking portion 442 is configured to limit the battery pack 2 mounted in the second direction X-to a second end position. In this embodiment, the first locking portion 441 and the second locking portion 442 are both recessed portions formed in the housing, the locking portion 27 is disposed at a position corresponding to the battery pack (close to the non-mounting end), the first locking portion 441 or the second locking portion 442 is engaged with the locking portion 27, so that the battery pack 2 can be locked, and the unlocking portion 28 connected to the locking portion 27 can be pressed to unlock the battery pack. The structure is matched with the existing battery pack, so that the battery pack mounting mechanism 4 can be compatible with the existing battery pack. In other embodiments, the battery pack mounting mechanism may also be provided with a separate latching mechanism.

Referring to fig. 6, the battery pack 2 further includes a third terminal set 23 and a cavity 24, and the third terminal set 23 and the cavity 24 are arranged along the installation direction of the battery pack 2. When the battery pack 2 is assembled in the housing 41 along the first direction X +, the third terminal set 23 is abutted with the first terminal set 42, and the second terminal set 43 is accommodated in the cavity; when the battery pack 2 is assembled to the housing 41 along the second direction X-, the third terminal set 23 is abutted with the second terminal set 41, and the first terminal set 42 is received in the cavity 24. The first terminal group 42 includes a first positive terminal 421 and a first negative terminal 422, the second terminal group 43 includes a second positive terminal 431 and a second negative terminal 432, the first positive terminal 421 is electrically connected with the second positive terminal 431 (for example, by a wire), and the first negative terminal 422 is electrically connected with the second negative terminal 432. Of course, the first terminal set 42 and the second terminal set 43 may further include a first detection terminal 423 and a second detection terminal 433, respectively, and the first detection terminal 423 is electrically connected to the second detection terminal 433.

Referring to fig. 7, in another embodiment, the battery pack may not have a cavity, the housing 41 includes a first groove set 415 and a second groove set 416, an orthogonal projection of the first terminal set 42 on the housing 41 is located in the first groove set 415, and an orthogonal projection of the second terminal set 43 on the housing 41 is located in the second groove set 416. In practice, each first groove of the first groove set 415 corresponds to each first terminal of the first terminal set 42, and each second groove of the second groove set 416 corresponds to each second terminal of the second terminal set 43. When the battery pack 2 is mounted to the housing 41 along the first direction X +, the battery pack 2 pushes the second terminal set 43 into the second groove set 416; when the battery pack 2 is mounted to the housing 41 along the second direction X-, the battery pack 2 pushes the first terminal set 42 into the first groove set 415, so that the existing battery pack can be compatible. Alternatively, the first terminal group 42 and the second terminal group 43 may be designed to have elasticity, or the terminal blocks (insulators for carrying and holding the terminals) of the first terminal group 42 and the second terminal group 43 may also be designed to be floating structures.

Referring to fig. 3, the battery pack mounting mechanism 4 further includes a first blocking plate 45 and a second blocking plate 46 (not shown in fig. 2), the battery pack 2 further includes a first end surface 221 (formed at the non-mounting end 22) and a second end surface 211 (formed at the mounting end 21) arranged along the mounting direction thereof, the first blocking plate 45 is movably mounted at a first end 411 of the housing 41, and the second blocking plate 46 is movably mounted at a second end 412 of the housing 41. When the battery pack 2 is mounted to the housing 41 along the first direction X +, the first baffle 45 is pressed by the battery pack 2 and located between the battery pack 2 and the housing 41, and the second baffle 46 covers the second end face 211 of the battery pack 2; when the battery pack 2 is mounted on the housing along the second direction X —, the second baffle 46 is pressed by the battery pack 2 and is located between the battery pack 2 and the housing 41, and the first baffle 45 covers the second end face 211 of the battery pack. The first baffle 45 and the second baffle 46 can cover the end face of the battery pack, the integrity and the aesthetic property of the electric tool are improved, and in addition, the first baffle 45 and the second baffle 46 also have a certain waterproof function. The electric quantity display structure of the battery pack can be arranged at the non-installation end.

Preferably, the first flap 45 is rotatably mounted to the first end 411 of the housing 41, and the second flap 46 is rotatably mounted to the second end 412 of the housing 41 (e.g., via a rotation shaft 451 as shown in the figures). The battery pack mounting mechanism 4 further includes a first returning element configured to drive the first shutter 45 from the position pressed by the battery pack 2 to the initial position, and a second returning element (not shown) configured to drive the second shutter 46 from the position pressed by the battery pack 2 to the initial position. The first and second reset elements can be selected from torsion springs, the spiral portion of the torsion spring is sleeved on the torsion spring, and the two arms of the torsion spring are respectively abutted against the first baffle 45 (or the second baffle 46) and the housing 41.

Preferably, when the battery pack 2 is mounted to the housing 41 in the first direction X +, the center of gravity G of the battery pack 2 is located at a first position, as shown in fig. 4; when the battery pack 2 is mounted to the housing 41 in the second direction X-, the center of gravity of the battery pack 2 is located at a second position, as shown in fig. 5; the distance L between the second position and the first position is not less than 10mm (assuming that the position of the tool body 1 does not change), and the line connecting the second position and the first position is inclined with respect to the output shaft 13. Based on the change of battery package focus, can finely tune the holistic focus of electric tool in direction from top to bottom and fore-and-aft direction (the battery package occupies 1/4 of angle grinder weight approximately, it is great to account for, can realize the focus of complete machine fine setting), when the user grips the instrument in the mode of adopting the difference to grip (for example, the palm carries out the grinding when transversely gripping, cut when vertically gripping), allow the user in fine adjustment machine focus position, make it be close to user's palm department as far as possible, in order to obtain better travelling comfort of gripping, promote user experience.

In other embodiments, the power tool may be a drill or other tool, such as shown in fig. 8 and 9. The battery pack 2A can be mounted to the tool body 1A from two opposite directions to achieve adjustment of parameters such as the outer contour and the center of gravity of the electric tool, and also facilitate assembly by a user.

In the application, the battery pack can be inserted in two directions, so that the outer contour of the battery pack and even the outer contour of the electric tool can be properly adjusted, the battery pack is prevented from interfering with the surrounding environment in a narrow space to influence the operation of a user, and the electric tool can be suitable for the narrow space; in addition, the bidirectional insertion is also beneficial to simplifying the installation process of the battery pack, and the user experience is improved; at the same time. Based on the change of the gravity center of the battery pack, the whole gravity center of the electric tool can be finely adjusted in the up-down direction and the front-back direction, so that the better holding comfort is obtained, and the user experience is further improved.

Although the present application has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application, and all changes, substitutions and alterations that fall within the spirit and scope of the application are to be understood as being covered by the following claims.