GB2074695A

GB2074695A - Vibration damping handles

Info

Publication number: GB2074695A
Application number: GB8109036A
Authority: GB
Original assignee: Seikoh Giken Co Ltd
Current assignee: Seikoh Giken Co Ltd
Priority date: 1980-03-28
Filing date: 1981-03-23
Publication date: 1981-11-04
Also published as: JPS56138541A; FI810814L; NO811049L; JPS6333571B2; DK123981A; SE443623B; AR224064A1; GB2074695B; AU6852081A; BE888158A; ES265897Y; NL8101470A; FR2479391B1; DE3111885A1; IT1143454B; CA1143390A; ZA811951B; AU538053B2; ATA144081A; IT8167419A0

Abstract

A vibration damper for a vibrational mechanical body, such as a chain saw or motorcycle, which is a source of vibration, comprises a support (2), such as an arm of the vibrational body for manipulation, and a cylindrical grip (3) mounted on the support (2). A vibration- damping coiled spring has units (4) defining small and large coiled portions disposed between the support (2) and the grip (3), with each of the small coiled portions being engaged with and supported by the support (2) and each large coiled portion by the inner surface of the grip (3). The vibration transmitted from the vibrational body to the support (2) is absorbed by the vibration- damping coiled spring to control or lessen the vibration transmission to the grip. <IMAGE>

Description

SPECIFICATION Vibration damper BACKGROUND OF THE INVENTION This invention relates to a vibration damper, and more specifically to a vibration damper for the handle or grip of a machine, vehicle, or the like which is a source of vibration, such as a chain saw or motorcycle.

The support for manual control of a chain saw, motorcycle, or other vibration-generating body is usually equipped with a cylindrical grip or the like for direct manipulation by the operator. Consequently, vibrations from the source are immediately transmitted to the support and the grip means, vibrating the hand or hands of the user, often so seriously as to impair his health. For example, the vibrations of chain saws in cutting operations are widely known to be responsible for Reynaud's disease. Attempts have heretofore been made to isolate the vibrations from those saws, motorcycles, and other similar sources to protect the human body. However, there has been no satisfactory solution proposed yet.

BRIEF SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a vibration damper for the handles or grips of chain saws, motorcycles, and other vibration-generating mechanical bodies, thereby to protect the users against Reynaud's disease and other injurious effects upon health.

A more specific object of the invention is to provide a vibration damper which comprises a spring assembly of a special construction through which a handle or grip is joined to a vibrational mechanical body.

With the vibrational damper of the invention the vibrations, to be otherwise transmitted from the mechanical source to the user through the handle or grip, are substantially damped or absorbed.

The above and further objects and features of the invention will be apparent from the following detailed description taken in connection with the accompanying drawing. It is to be understood, however, that the description of the invention as applied to the handle or grip of a chain saw is for the purpose of illustration only and is not intended as a definition of the limits of the invention.

BRIEF EXPLANATION OF THE DRAWINGS Figure 1 is a perspective view of a chain saw incorporating a vibration damper according to the invention; Figure 2 is a sectional view of a vibration damper embodying the invention; Figure 3 is a cross sectional view taken on the line I-I of Fig. 2; Figure 4 is a sectional view of another vibration damper embodying the invention; Figure 5 is a cross sectional view taken on the line ll-ll of Fig. 4; Figure 6 is a sectional view of another embodiment of the invention; Figure 7 is a cross sectional' view taken on the line 111-Ill of Fig. 6; Figure 8 is a sectional view of another embodiment; Figure 9 is a cross sectional view taken on the line IV-IV of Fig. 8; Figure 10 is a sectional view of still another embodiment; Figure 11 is a cross sectional view taken on the line V-V of Fig. 10;; Figure 12 is a sectional view of yet another embodiment; Figure 13 is a cross sectional view taken on the line VI-VI of Fig. 12; Figure 14 is a sectional view of a further embodiment; Figure 15 is a cross sectional view taken on the line VII-VII of Fig. 14; Figure 16 is a sectional view of yet a further embodiment; Figure 1 7 is a cross sectional view taken on the line VIlI-VIlI of Fig. 16; Figure 18 is a sectional view of still a further embodiment; Figure 19 is a cross sectional view taken on the line IX-IX of Fig. 18; Figure 20 is a sectional view of an even further embodiment; Figure 21 is a cross sectional view taken on the line X-X of Fig. 20; Figure 22 is a sectional view of an additional embodiment; Figure 23 is a cross sectional view taken on the line Xl-Xl of Fig. 22;; Figure 24 is a sectional view of another embodiment; Figure 25 is a sectional view of the vibration damper of Fig. 24 in use; Figure 26 is a sectional view of another embodiment; Figure 27 is a sectional view of still another embodiment; and Figure 28 is a sectional view of a further additional embodiment.

DETAILED DESCRIPTION OF THE INVENTION Briefly stated, the vibration damper according to the invention comprises a support, such as an arm, of a vibrational mechanical body, a cylindrical grip or handle provided concentri caily with the support, and adapted tb be held by the hand of an operator for manipulation, and a coiled or spiral spring having small and large coiled portions formed alternately, the spring being disposed between the support and the grip. Each small coiled portion is fixed to the support by welding or by suitable means such as a groove or ridge formed on the support, and each large coiled portion is engaged or contacted with the cylindrical grip or handle. This construction remarkably lessens vibrations.If rubber or other resilient material is employed, for example, as part of the cylindrical grip, the damper will attain a higher degree of vibration damping or absorption. The spring of the special configurations as described above may comprise either a single length with the alternate bulges and constrictions or a plurality of separate segmental or unit springs, each consisting of at least one large coiled portion and at least one small coiled portion. Also, the spring may be secured to the grip and the support by welding, grooving, bonding with adhesive, etc., or alternatively, it may be retained between the cylindrical grip and the support by means of flanges formed at the both ends of the grip.

As a further alternative, an inner cylinder may be provided instead of directly fixing the spring to the support or having it engaged with the latter. In this case, the grip, inner cylinder, and spring can be integrally assembled in advance.

In Fig. 1 there is shown, in perspective, a chain saw adapted to incorporate the vibration damper of the invention. The numeral 1 designates a housing accommodating the drives, hereinafter called the vibrational body because it constitutes a source of vibrations. The saw blade in the form of an endless chain is indicated at 28. The vibrational body 1 includes a support 2, such as an arm, to be gripped by the operator. A grip or handle 3 is sleeved over an upper portion of the support 2. The vibration damper according to the invention pertains to a structure joining the support 2 and the grip 3 together. This applies to all of the embodiments now to be described in detail.

Referring now to Figs. 2 and 3, one embodiment of the invention is illustrated. Throughout these and all other ensuing figures similar reference numerals indicate similar members or portions. On a tubular support 2, such as an arm, of a vibrational body is fitted a spring consisting of a row of barrel-shaped spring units 4, held in place by welding or other connecting means, such as grooves and stopper ridges formed on the support. This spring comprises an axial row of barrel-shaped units as shown, each unit starting with a neck or constriction, bulging midways, and again narrowing down to form the starting portion of the next unit in a cyclic arrangement. The envelope of the spring has sinusoidal or deformed sinusoidal contours. Since the spring has a plurality of constrictions of the same diameter, it can be directly secured to the support without the aid of other joining means.On the other hand, the plurality of bulges of the same diameter may be fixed to the inner surface of an inner cylinder 5' of metal, which in turn is fitted to the inner surface of the grip 3. In this way the spring comprising the barrel-shaped spring units 4 of alternate bulges and constrictions permits the grip to be fixedly mounted on the support to effect vibration damping. The inner cylinder 5' of metal is fitted in, or covered with, an outer sleeve 5 of vulcanized rubber or other resilient material, the both combinedly constituting the cylindrical grip 3. The outer sleeve 5 is formed with flanges 7" 72 at the both ends for contact with the both extremities 6t, 62 of the spring to keep the latter from moving axially.Thus it has some vibration damping or absorbing action, provides adequate friction for gripping, and prevents removal of the spring by means of the flanges 7, 72. Where desired, the spring may be cut off at given points of either the constricted or bulged portions into separate segmental springs.

Figs. 4 and 5 show another embodiment of the vibration damper according to the invention. Here, the spring is likewise secured to the support 2 and is similar in structure to that of the embodiment illustrated in Figs. 2 and 3 except that it ends at 6t, 62 with bulges instead. Also, the grip 3 in this embodiment is made of a single metal cylinder, which is bent at ends perpendicularly to the axis to form annular flanges 711, 72' for restrictive engagement with the bulged ends 61, 62 of the spring. The grip 3 in the form of a sleeve restricts the axial movement of the spring and prevents it from slipping off.

Another embodiment of the invention is shown in Figs. 6 and 7. Unlike the preceding embodiments, it has an inner metal cylinder 8 disposed between the tubular support 2 and the coiled spring having alternate constrictions and bulges and similarly fixed to the support.

The both ends of the inner cylinder are bent up at right angles to the axis to hold the opposite ends 6" 62 of constrictions of the spring unremovably. An outer metal cylinder 8', which forms the cylindrical grip 3, is flangeless and is secured by welding or the like to the bulges of the spring. This embodiment is easy to manufacture, because the inner and outer cylinders 8, 8' and the spring in a row of barrel-shaped units can be assem-bled beforehand and fixed as such to the support 2 to complete the necessary mounting work.

Figs. 8 and 9 show still another vibration damper embodying the invention. Here an inner metal cylinder 10 has upright flanges 13,. 132 engaged with constricted ends 6, 62 of a spring to hold the latter unmovably. In addition, the metal cylinder has cylindrical extensions 11,, 112 fixed to the support 2 by cap screws 12,, 122, respectively. An outer cylinder 10', constituting the grip, is formed of resilient material, such as hard rubber, to provide a buffer and an adequate friction for the hand of the operator.

In Figs. 10 and 11 is shown an embodi ment similar to the one shown in Figs. 8 and 9. The only difference is that the grip 3 of this embodiment consists of a rubber cylinder 10' and a metal cylinder 14 fitted inside as a lining, to which the spring is secured. In this case the rubber material may be softer than the counterpart in Figs. 8 and 9.

Another embodiment is shown in Figs. 1 2 and 1 3. Like all of the preceding embodiments it has a coiled spring 4 with its constrictions secured by suitable means to the tubular support 2. The bulges of the spring are bonded to the inner surface of the grip 3 made of hard rubber of other resilient material. The both ends of the grip 3 are formed with flanges 7" 72. A distinct feature of this embodiment is a plurality of nonslip, ringlike lands formed on the outer periphery of the grip 3. The lands enable the operator to take a firmer grip, with some damping effect in addition to the vibration-isolating effect of the coiled spring.

A similar embodiment of the invention is given in Figs. 1 4 and 1 5. Its grip 3 consists of a hard rubber cylinder having end flanges 7., 72 and also a plurality of nonslip lands 15' of sponge rubber provided on the outer periphery of the rubber cylinder. This structure is more effective in lessening the transmission of vibrations.

Figs. 1 6 and 1 7 illustrate another embodiment, in which the spring is divided into separate barrel-shaped segments 4, each having a constriction and a bulge and fixed to the tubular support 2. The grip is concentrically mounted on the spring. As shown, the grip 3 is a cylinder of hard rubber having a plurality of ringlike stiffening ribs 1 6 formed on its inner surface. In ringlike recesses 16' formed by the ribs, the bulges of the spring segments are fitted securely in place.

In a further embodiment of the invention shown in Figs. 1 8 and 19, a pair of spiral springs 4 are fixed to the tubular support 2, spaced apart at two points along, and in planes at right angles to, the axis of the support, by suitable means. Around those springs is fitted a grip 3, consisting of a metal cylinder 5' and an outer cylinder 5 of rubber or other resilient material attached to the cylinder and having flanges 7" 72 formed at opposite ends. Although the springs are coiled to configurations unlike those in the embodiments so far described, they achieve the same vibration damping effect as by the preceding ones.

Yet a further embodiment is shown in Figs.

20 and 21. The springs 4 are similar to those in Figs. 18 and 19 but, in order to retain them in the space between the support 2 and the metal cylinder 5', the support is formed with annular grooves 20 on the outer periphery and the metal cylinder is formed with corresponding annular grooves 21 on the inner surface, so that the both ends 18, 1 9 of each spring are fitted in each set of these grooves. In this way the damping portions and the grip are positively secured in position.

An even further embodiment of the invention, shown in Figs. 22 and 23, uses spiral springs 4 coiled in the same way as those in Figs. 18-21 but are made of narrow, flat bands instead of round wires.

Figs. 24 and 25 illustrate another embodiment, in which the spring 4 has a plurality of barrel-shaped units with alternate constrictions and bulges of given diameters. The constrictions are fixed to the tubular support 2. Concentrically with the support, an elongate, barrel-shaped grip 3 is mounted thereon. It consists of a rubber cylinder having hollow sections 22 varied stepwise in diameter and a complementary, reinforcing metal cylinder 23 of corresponding configurations fitted tight in the rubber cylinder. Thus the inside diameter of the metal cylinder 23 increases, section after section, from the both ends toward the middle portion. As indicated, only the bulges of the barrels near the both ends of the spring 4 are fixed to the metal cylinder 23.Therefore, while the magnitude of motion or vibration from a machine or the like as the source is small, the end spring sections will absorb it.

As the magnitude increases, the other spring sections will, one after another, take part in the vibration damping as shown, for example, in Fig. 25. The advantages of this embodiment are the comfort with which the operator can grip the damper and the smooth increase or decrease of vibration damping in proportion to changes in the magnitude of vibratory motion.

Fig. 26 shows yet another embodiment of the invention. This vibration damper includes a coiled spring 4 in a row of barrel-shaped units provided around the tubular support 2.

The spring is covered by a grip 3 consisting of a straight outer cylinder 5 of rubber formed with flanges 7" 72 and a metal cylinder 5' fitted as a lining for reinforcement. The bulges of the spring barrels are progressively reduced in diameter from the both ends toward the middle portion of the spring. Consequently, the damper functions in use in the same manner as that of Figs. 24 and 25.

Fig. 27 shows another embodiment as a modification of that which is illustrated in Figs. 18 and 19. Similarly, the spiral springs 4 in a pair are located in the same planes normal to the axis of the support 2, but this arrangement differs from the previous one in that the inner and outer ends of each spring are coiled double to ensure positive fixing to the support 2 and the reinforcing metal cylinder 5'.

A further additional embodiment shown in Fig. 28 utilizes the spiral springs of Figs. 1 8 and 1 9 but retain them in a different way.

The support 2 is formed with two annular grooves in spaced relation, collars 27" 272 are fitted in the grooves, and the vibrationdamping unit springs are kept in pressure contact with the inner sides of the collars facing each other. On the other hand, the grip 3 consists of a small-diameter, reinforcing metal cylinder 24 having large-diameter, flared ends 26" 262, and a rubber cylinder 25 snugly fitted in the thus-recessed outer periphery of the metal cylinder. Each unit spring is engaged on one side with the annular step defined by the flared end of the metal cylinder. These steps coact with the collars to retain the springs unremovably in place.

Claims

1. A vibration damper for a vibrational mechanical body, such as a chain saw or motorcycle, which causes a vibratory motion, comprising a support, such as an arm of said vibrational body for manipulation, a cylindrical grip mounted on said support, and a vibration-damping coiled spring having small and large coiled portions and disposed between said support and said grip, with each said small coiled portion being engaged with and supported by said support and each said coiled portion engaged with and supported by the inner surface of said grip, whereby the vibration transmitted from said vibrational body to said support is absorbed by said vibration-damping coiled spring to control or lessen the vibration transmission to said grip.

2. The vibration damper of claim 1, wherein said cylindrical grip consists of an outer cylinder of rubber or other resilient material lined with an inner cylinder of metal, and said vibration-damping coiled spring is divided into a plurality of barrel-shaped units arranged in an axial row, with the both extremities of the spring being engaged with and supported by flanges formed at both ends of said outer cylinder.

3. The vibration damper of claim 1, wherein said cylindrical grip consists of a single metal cylinder, and the both extremities of said vibration-damping coiled spring are engaged with and supported by flanges formed at both ends of said metal cylinder.

4. The vibration damper of claim 1, wherein said cylindrical grip consists of an inner and an outer metal cylinders held a suitable distance apart, and the both extremities of said vibration-damping coiled spring disposed in said space are engaged with and supported by flanges formed at both ends of said inner metal cylinder.

5. The vibration damper of claim 1, wherein said cylindrical grip consists of an inner metal cylinder and an outer cylinder of rubber or other resilient material suitably spaced apart, said inner metal cylinder having cylindrical extensions from both ends and secured thereat to said support by cap screws and also formed with flanges at the both ends by which the both extremities of said vibration-damping coiled spring disposed in said space are engaged and supported.

6. The vibration damper of claim 1, wherein said cylindrical grip consists of an inner metal cylinder and an outer cylinder of rubber or other resilient material suitably spaced apart, said inner metal cylinder having cylindrical extensions from both ends and secured thereat to said support by cap screws and also formed with flanges at the both ends by which the both extremities of said vibration-damping coiled spring disposed in said space are engaged and supported, said outer cylinder of resilient material being lined with a metal cylinder.

7. The vibration damper of claim 1, wherein said cylinder grip consists of a cylinder of rubber, synthetic resin, or other resilient material formed with a plurality of nonslip, ringlike lands on the outer periphery for ease of gripping.

8. The vibration damper of claim 1, wherein said cylindrical grip consists of a rubber cylinder having a plurality of nonslip lands of sponge rubber formed on the outer periphery for ease of gripping.

9. The vibration damper of claim 1, wherein said cylindrical grip consists of a rubber cylinder having a plurality of ringlike stiffening ribs formed on the inner periphery, and bulges of barrel-shaped units of said vibration-damping coiled spring are engaged with and supported by ringlike recesses formed between said stiffening ribs.

10. The vibration damper of claim 1, wherein said vibration-damping coiled spring consists of a plurality of unit springs each coiled spirally on one and the same plane at right angles to the axis of said support.

11. The vibration damper of claim 1, wherein said vibration-damping coiled spring consists of a plurality of unit springs each coiled spirally on one and the same plane at right angles to the axis of said support, the both inner and outer ends of each said unit springs being engaged with and supported by annular grooves formed, respectively, in said support and an inner metal cylinder of said grip.

1 2. The vibration damper of claim 1, wherein said vibration-damping coiled spring consists of a plurality of unit springs of narrow, flat leaf coiled spirally on one and the same plane at right angles to the axis of said support.

1 3. The vibration damper of claim 1, wherein said cylindrical grip is a thick-walled rubber cylinder having hollow sections reduced in diameter stepwise from the middle section endways and lined with a reinforcing metal cylinder.

14. The vibration damper of claim 1, wherein said cylindrical grip is a straight cylinder of rubber lined with a reinforcing metal cylinder, and said vibration-damping coiled spring consists of a plurality of barrel-shaped units progressively reduced in diameter from the both ends toward the middle portion of said spring.

1 5. The vibration damper of claim 1, wherein said vibration-damping coiled spring consists of a plurality of unit springs, the inner and outer ends of each said unit spring being coiled double for positive fixing to said support.

16. The vibration damper of claim 1, wherein said cylindrical grip consists of a metal cylinder having a small-diameter, recessed cylindrical section, and an outer cylinder of rubber or other resilient material fitted in said recessed cylindrical section, and spirally coiled unit springs are disposed in the spaces between the inner peripheries of flared ends of said metal cylinder and the outer periphery of said support and are engaged with and supported by collars fixed to said support.

1 7. A vibration damper for a vibrational mechanical body substantially as hereinbefore described with reference to the accompanying drawings.

1 8. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.