KR20170006347A

KR20170006347A - Two-axle wheel assembly and rail guided vehicle having the same

Info

Publication number: KR20170006347A
Application number: KR1020150096803A
Authority: KR
Inventors: 손후현
Original assignee: 주식회사알투웍스
Priority date: 2015-07-07
Filing date: 2015-07-07
Publication date: 2017-01-18

Abstract

According to an embodiment of the present invention, a two-axle wheel assembly to be mounted on a rail-guided vehicle (RGV) comprises a first reception member, a wheel sub-assembly, and an axle connection member. The first reception member has a cylindrical shape, is fixed to a chassis of the RGV, and receives a first axle in a vertical direction. The wheel sub-assembly to be mounted on an RGV has at least one wheel to be in physical contact with a rail and has either a second axle in the vertical direction or a second reception member receiving the second axle. The connection member includes one end including the first axle, is rotationally coupled to the first reception member, and has the other end rotationally coupled to the wheel sub-assembly. When the wheel sub-assembly has the second axle, the shaft connection member has the second reception member receiving the second axle. When the wheel sub-assembly has a second reception member, the shaft connection member has the second axle to be received in the second reception member.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a two-axle wheel assembly and a rail guided vehicle having the two-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxial wheel assembly and a rail guided vehicle having the same, and more particularly, to a biaxial wheel assembly and a rail guiding type transportation vehicle having the biaxial wheel assembly, It is about the car.

Rail Guided Vehicle (RGV) is a means of transporting goods to a designated location and running along a circular or rectilinear rail installed in a workshop such as a factory or a large warehouse. Generally, an automatic control system It is an unmanned car that is driven.

Rails used to guide RGVs include monorails and dual rails. In the case of RGVs using monorails, the curved rail section can be designed relatively freely, but it is difficult to load large quantities of the parcel at one time compared with the RGV using dual rails. On the other hand, when the double rail is used, there is a merit that a relatively large number of articles can be transferred with stability. However, there is a disadvantage that a curved section having a small radius of curvature can not be freely designed in a narrow work area.

In this regard, Figures 1a and 1b illustrate the problem of an RGV vehicle using a conventional dual rail. FIGS. 1A and 1B are a top view of a vehicle 100, which is placed on a double rail 200 having a straight section and a curved section, respectively.

Referring to FIG. 1A, the vehicle 100 travels in a straight line section with the front wheels 110 and 120 and the rear wheels 130 and 140 resting on the rail 200. In this case, the distance between the left and right wheels is L, and the distance between the left and right rails of the double rail 200 is L. The wheels are connected to the vehicle body of the vehicle 100 by vertical axes 111, 121, 131 and 141, and can rotate left and right around the vertical axis 111 in a curved section.

Referring to FIG. 1B, it is assumed that the carriage 100 is placed in a curved section having a curvature radius from the outer rail to the center point c of the double rail 200. At this time, the distance between the left and right wheels of the front wheels 110 and 120 is a fixed length, but the distance between the right and left rails of the double rail 200 along the virtual line extending the left and right wheels of the front wheel becomes longer than L, There is a problem that the right front wheel 110 and the rear wheel 130 of the vehicle 100 are not seated on the rails and are derailed. This problem becomes more serious when the radius of curvature is smaller, and is more problematic when a sharp curved section with a small radius of curvature is required due to the limited area of the work area.

According to an embodiment of the present invention, there is provided a biaxial wheel assembly and a rail guided vehicle (RGV) including the same, which enables operation without derailment of a vehicle even in a dual rail curved section having a small radius of curvature.

According to an embodiment of the present invention, there is provided a biaxial wheel assembly and a rail guided vehicle (RGV) having the same, wherein the vehicle can be mounted on a rail even when the distance between left and right rails of the double rail is different .

According to an embodiment of the present invention, there is provided a wheel assembly mountable to a rail guided vehicle (RGV), comprising: a cylindrical first receiving member fixed to a vehicle body of the vehicle and accommodating a first axis in a vertical direction; A wheel subassembly having one of at least one wheel in physical contact with the rail and a second receiving member receiving a second axis in a vertical direction or a second axis; And a shaft connecting member rotatably coupled to the first receiving member including a first shaft at one end and pivotally coupled to the wheel subassembly at the other end, wherein the wheel subassembly has a second shaft Wherein the shaft connecting member has a second receiving member for receiving the second shaft, and when the wheel subassembly has the second receiving member, the shaft connecting member has a second shaft that can be received in the second receiving member Wherein the RGV mounting wheel assembly comprises:

According to an embodiment of the present invention, there is provided a rail guided vehicle (RGV) operable on a dual rail, comprising a wheel physically contacting the first rail of the double rail, the first side of the vehicle ' Two first wheel assemblies that are spaced apart from each other by a predetermined distance and are coupled to each other; And two second wheel assemblies each having a wheel physically contacting the second rail of the double rail and spaced apart from each other at a second side of the right and left sides of the vehicle body of the vehicle, Wherein the first wheel assembly is a biaxial wheel assembly having two axes as described above.

According to the embodiment of the present invention, there is an advantage that the vehicle can be operated without derailment even in a double rail curved section with a small radius of curvature.

According to the embodiment of the present invention, there is an advantage in that even when the distance between the left and right rails of the double rail is different, the vehicle can be seated on the rail and operated.

FIGS. 1A and 1B are views for explaining problems of a conventional rail guided vehicle (RGV)
2 is a perspective view of an RGV equipped with a biaxial wheel assembly according to an embodiment of the present invention,
3 is an exploded perspective view of an RGV according to one embodiment,
4 is a perspective view of a two-axis wheel assembly according to one embodiment,
5 is an exploded perspective view of a biaxial wheel assembly according to an embodiment,
6 is an exploded perspective view of a wheel subassembly according to one embodiment,
FIG. 7 is a cross-sectional perspective view showing a state in which a biaxial wheel assembly according to an embodiment is mounted on a vehicle;
8 is a cross-sectional view of a two-axis wheel assembly according to one embodiment,
9 is a view for explaining a state in which an RGV equipped with a two-axis wheel assembly according to an embodiment is running on a curved rail.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments with reference to the accompanying drawings, Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

In this specification, when an element is referred to as being "above" (or "below", "right", or "left") another element, , Or that a third component may be interposed therebetween. In the drawings, the thickness of the components is exaggerated for an effective explanation of the technical content.

Also, in this specification, expressions such as 'upper', 'lower (lower)', 'left', 'right', 'front', 'rear' And it is a relative expression used for convenience of explanation based on the drawings when describing the present invention with reference to the respective drawings.

When the terms first, second, etc. are used herein to describe components, they should not be limited by these terms. These terms are used only to describe a component with other components The embodiments described and exemplified herein also include their complementary embodiments.

As used herein, the terms 'comprise' and / or " comprising ", as used herein, are intended to encompass all types of elements, including, Or < / RTI >

Hereinafter, the present invention will be described in detail with reference to the drawings. In describing the specific embodiments below, various specific details have been set forth in order to explain the invention in greater detail and to assist in understanding it. However, it will be appreciated by those skilled in the art that the present invention may be understood by those skilled in the art without departing from such specific details. In some cases, it should be mentioned in advance that it is common knowledge in describing an invention that parts not significantly related to the invention are not described in order to avoid confusion in explaining the present invention.

FIG. 2 is a perspective view of an RGV vehicle 100 equipped with a two-axis wheel assembly according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of the vehicle 100. Referring to FIG.

Referring to the drawings, the vehicle 100 includes receiving grooves 151, 152, 153, and 154 for receiving wheel assemblies in a vehicle body 150 of a vehicle. In the illustrated embodiment, the receiving grooves 151, 152, 153, and 154 are formed on the right and left sides of the front of the vehicle body 150 and on the left and right sides of the rear side, respectively. Preferably, the receiving groove is a through-hole that passes through the upper surface and the lower surface of the vehicle body 150. Further, guide openings 161 vertically penetrating adjacent to the front and rear receiving grooves 151 and 153 on the right side are further formed.

The wheel assembly is rotatably attached to each of the receiving grooves 151, 152, 153, 154 of the carriage 100. In the illustrated embodiment, the first wheel assembly 300 is coupled to the right front side and the rear side of the vehicle body 150, respectively, and the second wheel assembly 400 is coupled to the left front side and rear side.

The first wheel assembly 300 has a wheel physically contacting the right rail 200a of the dual rail 200 and includes receiving grooves 151 and 153 spaced apart from each other at the right and left sides of the vehicle body 150, Respectively.

In the illustrated embodiment, the first wheel assembly 300 comprises a fixed shaft receiving member 10, a shaft connecting member 20, and a wheel subassembly 50. The fixed shaft receiving member 10 is received and fixedly received in the receiving grooves 151 and 153 of the vehicle body 150 of the transportation vehicle. The wheel subassembly 50 includes a wheel that physically contacts the rail 200a and includes a pivot shaft (70 of Fig. 5) vertically protruding above the body of the wheel subassembly. The shaft connecting member 20 includes a fixed shaft 22 rotatably coupled to the fixed shaft receiving member 10, a movable shaft receiving member 23 capable of receiving the movable shaft 70, And a connecting plate 21 connecting the movable shaft receiving member 23 and the connecting shaft 21 to each other. Since the first wheel assembly 300 is configured to include the fixed shaft 22 and the movable shaft 70, the first wheel assembly 300 is a two-axis wheel structure having two axes.

The fixed shaft receiving member 10 is received and fixed in the receiving grooves 151 and 153 of the vehicle body 150 and the movable shaft receiving member 23 is positioned in the guide openings 161 and 163 of the vehicle body 150 do. At this time, the guide openings 161 and 163 are formed in the guide openings 161 and 163 in such a manner that the guide openings 161 and 163 are opened and closed with respect to the fixed shaft 22 along the arcs of the length whose radial distance between the fixed shaft 22 and the movable shaft 70 And is formed so as to be movable within an angular range.

On the other hand, the second wheel assembly 400 has a wheel physically contacting the left rail 200b of the double rail 200, and has receiving grooves 152 and 154 spaced apart from each other by a predetermined distance from the left side of the vehicle body 150 Respectively.

The second wheel assembly 400 includes a fixed shaft receiving member 410 and a wheel subassembly 420. Similar to the fixed shaft receiving member 10 of the first wheel assembly 300, the fixed shaft receiving member 410 of the second shackle assembly 400 is accommodated in the receiving grooves 152, 154 of the vehicle body 150 Can be combined. The wheel subassembly 420 of the second wheel assembly 400 has a similar structure to that of the wheel subassembly 50 of the first wheel assembly 300 and the wheel subassembly 420 is in physical contact with the rail 200b Wheel. The wheel subassembly 420 includes a fixed shaft vertically protruding from the upper portion of the body of the wheel subassembly. The fixed shaft is rotatably coupled to the fixed shaft receiving member 410, 400 may rotate about the fixed axis 410. [0054]

The first and second wheel assemblies 300 and 400 of FIGS. 2 and 3 may be configured such that the axle shaft receiving member 23 of the first wheel assembly 300 is inserted into the guide openings 161 and 163 of the vehicle body 150 The distance between the wheel of the first wheel assembly 300 and the wheel of the second assembly 400 may vary.

The term "fixed shaft " as used herein does not mean that the shaft does not rotate, but means that the shaft does not move relative to the vehicle body 150. The fixed shaft 22 of the first wheel assembly 300 is rotatably coupled to the fixed shaft receiving member 10 fixedly coupled to the vehicle body 150 so that the fixed shaft 22 rotates about its own axis But there is no relative movement with respect to the vehicle body 150. Fig. The term "shaft" as used herein means that the shaft can rotate not only by itself, but also that the shaft can move relative to the vehicle body 150. For example, the movable shaft (70) can move around the fixed shaft (22) along an arc whose radius is the distance between the fixed shaft (22) and the movable shaft (70).

As shown, the right rail 200a corresponds to the inner rail in the curve section and the left rail 200b corresponds to the outer rail. That is, in the illustrated embodiment, the first wheel assembly 300 is disposed to contact the inner rail 200a and the second wheel assembly 400 is disposed to contact the outer rail 200b. However, in an alternative embodiment, the arrangement of the first and second wheel assemblies 300 and 400 may be changed so that they are in contact with the outer rails 200b and the inner rails 200a, respectively.

Although not shown in the drawings, the vehicle 100 may further include various components in accordance with the specific embodiment. For example, the vehicle body 150 may be provided with a variety of equipment necessary for loading the article, and a driving device for driving and moving the vehicle may be disposed above or below the vehicle body 150. For example, such a driving device may be implemented to transmit a driving force to a wheel mounted on at least one wheel assembly 300 of the four wheel assemblies 300, 400 disposed in the vehicle 100. It will be understood, however, that such apparatuses and apparatuses are unnecessary in explaining the gist of the present invention, and thus are not shown in the drawings and the description thereof is omitted.

Hereinafter, the first wheel assembly 300 having a biaxial wheel structure according to an embodiment of the present invention will be described in detail with reference to FIGS. 4 to 8. FIG.

4 is a perspective view of a wheel assembly 300 according to an embodiment, and FIG. 5 is an exploded perspective view.

In the illustrated embodiment, the first wheel assembly 300 includes a fixed shaft receiving member 10, a shaft connecting member 20, and a wheel subassembly 50.

The fixed shaft receiving member 10 is a cylindrical member that receives the fixed shaft 22 of the shaft connecting member 20. The fixed shaft receiving member 10 is inserted into and fixedly coupled to the receiving grooves 151 and 153 of the vehicle body 150 of the vehicle. In an alternative embodiment, the fixed shaft receiving member 10 may be cylindrical and open only at the top and closed at the bottom.

The wheel subassembly 50 is a member that receives a wheel in physical contact with the rail 200a. The wheel subassembly 50 includes a vertical wheel 90 rotatably coupled by a wheel axle 69 and preferably includes at least one horizontal wheel 80 as an auxiliary wheel in physical contact with both sides of the rail, . The vertical wheel 90 and the at least one horizontal wheel 80 are in contact with the upper surface and both sides of the rail 200a to support the vehicle body 150 so that the vehicle 100 does not deviate to the outside or inside of the rail It can be operated on the rail in a stable manner.

In the illustrated embodiment, the wheel subassembly 50 includes a pivot shaft 70 vertically protruding therefrom in order to be connected to the shaft connecting member 20.

The shaft connecting member 20 includes a fixed shaft 22, a fluid shaft receiving member 23 and a connecting plate 21 connecting the fixed shaft 22 and the fluid shaft receiving member 23 to each other. The fixed shaft 22 can be rotatably coupled to the fixed shaft receiving member 10. The shaft receiving member 23 may be rotatably coupled to the shaft 70 of the wheel subassembly 50. Accordingly, the shaft connecting member 20 is rotatable around the fixed shaft 22 and is also capable of rotating around the movable shaft 70. In this case, if the fixed shaft 22 is fixed to the vehicle body 150 of the carrier, the movable shaft 70 is positioned at a position where the distance between the axes of the movable shaft 70 and the fixed shaft 22 about the fixed shaft 22 Can be moved along an arc of a radius.

On the other hand, in an alternative embodiment, the mounting positions of the shaft (22, 70) and the receiving member (10, 23) on this shaft can be exchanged with each other. That is, in the illustrated embodiment, although the shaft 70 is formed in the wheel subassembly 50 and the shaft receiving member 23 is formed in the shaft connecting member 20, in an alternative embodiment, May be formed on the shaft connecting member 20 and the shaft receiving member 23 may protrude from the upper portion of the wheel subassembly 50. [ Likewise, in another alternative embodiment, it will be appreciated that the fixed shaft 22 may be formed in the vehicle body 150 of the carrier and the cylindrical fixed shaft receiving member 10 may be formed in the shaft connecting member 20 .

Now, an exemplary detailed structure of the first wheel assembly 300 will be described with reference to FIGS. 6 to 8. FIG.

FIG. 6 is an exploded perspective view of the wheel subassembly 50 according to an embodiment, FIG. 7 is a cross-sectional perspective view of the first wheel assembly 300 mounted on the vehicle body 150 of the vehicle, 1 wheel assembly 300 of FIG.

6, the wheel subassembly 50 according to one embodiment includes an assembly body 60, a shaft 70 protruding from the top of the body, and a vertical wheel (not shown) rotatably coupled to the body, 90 and a plurality of horizontal wheels 80.

The shaft 70 is a member rotatably coupled to the shaft receiving member 23 of the shaft connecting member 20 by one or more bearings 73. The lower portion of the shaft 70 is integrally joined with the shaft-shaped plate 71 formed to be flat to engage with the body 60 of the wheel subassembly 50. The shaft 71 and the shaft-shaft 70 may be formed integrally or separately from each other.

In one embodiment, the body 60 of the wheel subassembly 50 includes an upper connecting plate 61 coupled to the shaft connecting plate 71, and a lower connecting plate 61 extending vertically downward from both sides of the upper connecting plate 61 A pair of side plates 62, and a wheel shaft 69 passing through at least one of the pair of side plates 62. In the illustrated embodiment, the pair of side plates 62 is formed with a through hole 67 through which the wheel axle 69 can pass, and the vertical wheel 90 and the bearing 93 are connected to both side plates 62 The wheel shaft 69 passes through the through hole 67 and is fastened to the side plate 62 so that the vertical wheel 90 is rotatably coupled to the body 60. [

The vertical wheel 90 is in physical contact with the upper surface of the rail 200 and serves to support the vehicle 100 on the rail and preferably the wheel sub- Further includes a plurality of horizontal wheels (80) that physically contact both sides of the rail (200) to support the carriage (100) so as not to move to the left or right of the rail.

In the illustrated embodiment, the body 60 of the wheel subassembly 50 may further include a front connecting plate 63 and a rear connecting plate 64, which are flat on the front and rear sides, respectively. The front and rear connection plates 63 and 64 may extend integrally from the front and rear portions of the pair of side plates 62 and may be integrally formed with the front and rear connection plates 63 and 64 and the side plates 62 ) May be formed separately and then integrally bonded to each other. The horizontal wheel 80 is rotatably coupled to the horizontal wheel support plate 81 through a through hole 83 and is connected to the front and rear connection plates 63 and 64 of the body 60 by a horizontal wheel support plate 81, A pair of horizontal wheels 80 are arranged in front of the vertical wheel 90 and a pair of horizontal wheels 80 are arranged in the rear as shown. At this time, preferably each of the pair of horizontal wheels 80 is disposed so as to be in contact with the inner side surface and the outer side surface of the protruded shaped rail 200, respectively.

7 and 8, the wheel subassembly 50 of the first wheel assembly 300 constructed as described above is inserted into the shaft receiving member 23 of the shaft connecting member 20, And is rotatably coupled to the shaft connecting member 20. The shaft connecting member 20 is rotatably coupled to the vehicle body 150 by inserting the fixed shaft 22 of the shaft connecting member 20 into the fixed shaft receiving member 10 mounted on the vehicle body 150. [ The wheel subassembly 50 rotates not only about the axis of rotation 70 but also along the arc of the radius between the axis of the fixed shaft 22 and the axis of the shaft 70 in the guide opening 161 And can rotate about the fixed shaft 22.

9 is a view for explaining a state in which the RGV transporter equipped with the wheel assembly according to the above-described embodiment runs on a curved rail.

It is assumed that the RGV carriage 100 travels in a curved rail section curving to the right. The first wheel assembly 300 is mounted on the right and rear sides of the vehicle body 150 of the vehicle 100 so as to be in contact with the inner rail 200a and the second wheel assembly 400 is mounted on the left front side and rear side of the vehicle body 150, And is in contact with the outer rail 200b.

In this case, when the left and right wheel assemblies in front of the vehicle are taken as an example, the distance between the fixed shaft 22 of the first wheel assembly 300 and the fixed shaft of the second wheel assembly 400 is smaller than the interval between rails, The link plate 21 of the one wheel assembly 300 rotates about the fixed shaft 22 so that the movable shaft 70 can continue to travel on the rail 200a without leaving the right rail 200a.

In addition, when the vehicle equipped with the first wheel assembly according to the embodiment of the present invention is used, there is an advantage that the vehicle can be used as it is without modification on two rails having different intervals between rails.

That is, for example, when two rails with different spacing between rails are provided, the distance between the left and right wheels of the vehicle according to the conventional configuration is adjusted to the rail-to-rail spacing of one rail, will be. However, when the biaxial wheel assembly according to the embodiment of the present invention is mounted, the distance between the left and right wheels can be adjusted by moving the moving shaft 70 by the rotation of the connecting plate 21, Rails also have the advantage that they can be used as is.

Various modifications and variations of the present invention are possible in light of the above teachings. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the scope of the appended claims, as well as the appended claims.

10: Fixed shaft receiving portion
20:
21: Connection plate
22: Fixed shaft
23:
50: wheel subassembly
60: sub-assembly body
70:
80: Horizontal wheel
90: Vertical wheel
100: Car carrier
300: first wheel assembly
400: second wheel assembly

Claims

A wheel assembly mountable on a rail guided vehicle (RGV), comprising:
A cylindrical first receiving member (10) fixed to the vehicle body (150) of the carrier and receiving a first axis in the vertical direction;
A wheel subassembly (50) having one of at least one wheel in physical contact with the rail and a second receiving member receiving a second axis in the vertical direction or a second axis in the vertical direction; And
And a shaft connecting member (20) rotatably coupled to the first housing member (10) including a first shaft (22) at one end and pivotally coupled to the wheel subassembly (50) at the other end ,
The shaft connecting member 20 has a second receiving member for receiving the second shaft when the wheel subassembly 50 has a second shaft and the second receiving member for receiving the second receiving member when the wheel subassembly 50 has the second receiving member, , And the shaft connecting member (20) has a second shaft that can be received in the second receiving member.

The method according to claim 1,
Wherein the first shaft is fixed to the vehicle body (150) of the carrier, and the second shaft is movable along an arc having a radius of the first axis and the second axis about the first axis. Wheel assembly.

The method according to claim 1,
Characterized in that the wheel subassembly (50) comprises the second shaft (70) and the shaft connecting member (20) comprises a cylindrical second receiving member (23) for receiving the second shaft. Wheel assembly for RGV mounting.

4. The wheel assembly (100) of claim 3, wherein the wheel subassembly (50)
A sub-assembly body 60 coupled to the second shaft 70; And
And a vertical wheel (90) rotatably coupled to the subassembly body (60) and capable of physically contacting the upper portion of the rail.

5. The method of claim 4,
The sub-assembly body (60)
An upper connecting plate (61) coupled with the second shaft (70);
A pair of side plates (62) extending vertically downward from both side surfaces of the upper connection plate (61); And
And a wheel shaft (69) passing through at least one of the pair of side plates (62)
Characterized in that the vertical wheel (90) is interposed between the pair of side plates (62) and is rotatably engaged by the wheel axle (69).

5. The method of claim 4,
The wheel subassembly (50) further comprises at least a pair of horizontal wheels (80) rotatably coupled to the subassembly body (60) and physically contactable to both sides of the rail. Wheel assembly for RGV mounting.

In a rail guided vehicle (RGV) capable of operating on a dual rail,
Two first wheel assemblies 300 each having a wheel physically contacting with the first rail of the dual rail and spaced apart from each other at a first side of the right and left sides of the vehicle body 150 of the vehicle; And
Two second wheel assemblies 400 having wheels that are in physical contact with the second rails of the double rail and are respectively spaced apart from each other at a second side of the left and right sides of the vehicle body 150 of the vehicle, Including,
Wherein the first wheel assembly (300) is an RGV mounting wheel assembly according to any one of claims 1 to 6.

8. A rail-guided vehicle according to claim 7,
Receiving grooves (151, 153) formed in the surface of the vehicle body (150) of the vehicle for receiving the first housing member (10) of the first wheel assembly (300); And
Wherein the second housing member (23) of the first wheel assembly (300) includes guide openings (161, 163) formed so as to vertically penetrate the vehicle body (150)
Wherein the guide openings (161, 163) are formed so that the second housing member (23) can move along an arc of a predetermined length having a radius between the first axis and the second axis. The car.

9. The method of claim 8,
The distance between the wheel of the first wheel assembly 300 and the wheel of the second assembly 400 varies as the second housing member 23 moves within the guide openings 161 and 163 Rail-guided vehicle.

8. The method of claim 7,
Further comprising a drive device for transmitting a driving force to at least one wheel of the two wheel assemblies and the two wheel assemblies.