ISO 9191:1991 芝生と庭の乗用（乗馬）トラクター—スリーポイントヒッチ | ページ 2

2.3.1

リンケージ

1 つの上部リンクと 2 つの下部リンクの組み合わせで、それぞれが反対側の端でトラクターと機械に連結され、機械をトラクターに接続します。

2.3.2

ヒットポイント

ラインと作業機の間の連結。幾何学的解析では、ヒッチ ポイントは、リンクと機械の間の関節接続の中心として確立されます。

2.3.3

リンクポイント

リンクとトラクター間の連結。幾何学的解析では、リンク ポイントは、リンクとトラクター間の関節接続の中心として確立されます。

2.1

ride-on (riding) machine; lawn and garden tractor; turf (riding) tractor

Self-propelled machine on which an operator rides, designed primarily for cutting grass and auxiliary garden work. The cutting means may be an integral part of the machine or suspended from or attached to the machine. ¹⁾

2.2

attachment

Optional assembly of components that can be mounted on a lawn and garden ride-on (riding) tractor for a specific use.

2.4.1

upper link ①; lower link ②

Elements as appropriate in the linkage, each fitted with an articulated connection at both ends.

2.4.2

upper hitch point ③

Articulated connection between the upper link and the implement.

2.4.3

upper link point ⑤

Articulated connection between an upper link and the tractor.

2.4.4

lower hitch point ④

Articulated connection between a lower link and the implement.

2.4.5

lower link point ⑥

Articulated connection between a lower link and the tractor.

2.4.6

upper hitch pin ⑦

Pin, usually detachable and forming part of the upper link assembly, that connects the upper link to the implement.

2.4.7

lower hitch stud or pin ⑧

Stud or pin attached to the implement, on which a lower link is secured.

2.4.8

mast ⑨

Member that provides attachment of the upper link of the implement.

2.4.9

lift linkage

Connecting linkage that transmits force to the lower links for raising and lowering implements.

Figure 1—Tractor linkage

Table 1—Implement dimensions

Symbol	Measurement	Dimension
		min.	max.
	Upper hitch point:
b1	Width Inside	27	—
b2	Width outside	—	49
r1	Clearance radius for upper link	38	—
d1	Hitch pin hole diameter	17	18
	Lower hitch point:
d2	Stud (hitch pin) diameter	15	16
l1	Linchpin hole distance	37	—
d3	Linchpin hole diameter	6	8
l2	Lower hitch point span	500	508
r2	Clearance radius for lower link	50	—
	Implement encroachment in front of lower hitch point if implement extends laterally behind tyre	—	13
h1	Implement mast height (see 3.3)	—	305

Dimensions in millimetres

Figure 2—Implement hitch

2.5.1

mast height

Perpendicular distance between the upper hitch point and common axis of the lower hitch points.

2.5.2

levelling adjustment

Adjustment of lower links so that the one lower hitch point may be moved vertically with respect to the other lower hitch point to provide an inclination of the implement.

2.5.3

lower hitch point span

Distance between lower hitch points measured at the base of the lower hitch stud, or the distance between the innermost restraining means provided on the implement.

2.5.4

linchpin hole distance

Distance between the linchpin hole centreline and the lower link stud base.

2.5.5

lift range

Range of movement of the lower hitch points using the extent of manual adjustment provided in the lift linkage in conjunction with the power range, expressed as the maximum and minimum possible heights of the lower hitch points above ground level, the lower hitch point axis being maintained horizontal to the ground.

2.5.6

power range

Total vertical movement of the lower hitch point excluding any adjustment in the linkage or lift linkage.

2.5.7

lower hitch point tyre clearance

Clearance expressed as a radial dimension from the lower hitch point to the outside diameter of the tyre with the implement in any position and all side-sway eliminated from the links.

2.5.8

lower hitch point tractor clearance

Horizontal dimension between the rearmost parts of the tractor in the area between the two draft links and the horizontal line through the two lower hitch points throughout the range of vertical movement of the hitch points.

2.5.9

mast adjustment

Usable range of movement of the mast in a vertical plane. It is measured as the maximum and minimum heights of the lower hitch points above the ground between which a mast of standard height can be adjusted to any inclination between vertical and 5° from vertical rearwards. Adjustment of the mast controls the pitch of the implement.

Note 1 to entry: Specifying the mast adjustment to be provided enables the tractor designer to determine the minimum acceptable top link length adjustment in relation to the lower linkage attachment points. It also permits the implement manufacturer to determine the range over which pitch adjustment can be obtained.