GB2042973A - Saw - Google Patents

Saw Download PDF

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Publication number
GB2042973A
GB2042973A GB7909160A GB7909160A GB2042973A GB 2042973 A GB2042973 A GB 2042973A GB 7909160 A GB7909160 A GB 7909160A GB 7909160 A GB7909160 A GB 7909160A GB 2042973 A GB2042973 A GB 2042973A
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GB
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Application
Patent type
Prior art keywords
saw
slider member
counterweight
connecting rod
oscillations
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB7909160A
Original Assignee
Freund R
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23DPLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
    • B23D51/00Sawing machines or sawing devices working with straight blades, characterised only by constructional features of particular parts; Carrying or attaching means for tools, covered by this subclass, which are connected to a carrier at both ends
    • B23D51/16Sawing machines or sawing devices working with straight blades, characterised only by constructional features of particular parts; Carrying or attaching means for tools, covered by this subclass, which are connected to a carrier at both ends of drives or feed mechanisms for straight tools, e.g. saw blades, or bows

Abstract

A saw having a slider member 1 which can be reciprocated by a connecting rod 5 and to which a saw blade 2 may be secured, and a counterweight 14 which is movable by a further connecting rod 12 in opposition to the slider member, wherein the connecting rods are mounted on two opposite sides of a crank disc 8 which is provided with external teeth 10 and which is rotatably mounted in a drive housing in a bearing 9 and which is engaged by means of its external teeth with a drive pinion 16. <IMAGE>

Description

SPECIFICATION Saw The present invention relates to a driven saw particularly such a saw in which a reciprocating blade is held at one end. Among the saws to which the application is applicable are compass saws, fretsaws, keyhole saws and tenon-saws.

Saws have been proposed having a slider member which can be moved up and down by a connecting rod and to which a saw blade may be secured, and a counterweight which is movable by a further connecting rod, in opposition to the slider member. Providing a counterweight for the slider member and the saw blade is intended to cause the oscillations which occur in operation, due to the upward and downward movements of the slider member with the saw blade, to be nullified or substantially eliminated. Hitherto, the two connecting rods have been connected to a crankshaft. The mounting for the crankshaft is relatively expensive and the crankshaft itself is a complicated and also large component. This has a hightly detrimental effect both in regard to manufacturing costs and also the dimensions of the saw.

Furthermore, in the previously proposed saws, it is inevitable that considerable transverse oscillations occur due to the relatively large distance between the connecting rods, so that in many cases the desired effect, namely reducing longitudinal oscillations by the provision of a counterweight, is nullified by the transverse oscillations which are produced.

There is therefore a need for a saw of the kind set out above, which is of small dimensions and which has low manufacturing costs, and in which oscillations do not occur or oscillations occur to an extent which is of no significance from the practical point of view.

According to the present invention, there is provided a saw having a slider member which can be reciprocated by a connecting rod and to which a saw blade may be secured, and a counterweight which is movable by a further connecting rod in opposition to the slider member, wherein the connecting rods are mounted on two opposite sides of a crank disc which is provided with external teeth and which is rotatably mounted in a drive housing in a bearing and which is engaged by means of its external teeth with a drive pinion.

Using a crank disc which is mounted only in a bearing such as a ball bearing assembly provides a considerable reduction both in manufacturing costs and also in the overall dimensions of the drive unit of the saw, and also provides that the two connecting rods are spaced from each other by only a very small distance, so that transverse oscillations do not occur, or occur only to an insignificant extent, in operation of the saw.

An embodiment of the invention is described in greater detail hereinafter by way of example with reference to the drawing in which:~ Figure 1 shows a view in longitudinal section through a drive housing of a power-driven compass saw according to the invention, including the saw blade, but without showing a drive motor, and Figure 2 shows a view in the direction of the arrow II in Figure 1, with the cover of the drive housing removed.

Figures 1 and 2 show the main components of a compass saw according to the invention. A saw blade 2 is secured to a slider member 1 which is mounted for axial displacement in a bush 3 which is fitted into an end wall of a drive housing 4.

A connecting rod 5 is connected by way of a pin 6 to the end of the slider member 1 which projects into the interior of the housing 4. The connecting rod 5 is connected by its other end to a crank pin 7 which in turn is secured to a crank disc 8.

The crank disc 8 is mounted rotatably in a ball or roller bearing assembly 9 within the housing 4 and is provided with external teeth 10.

At the side of the crank disc 8 which is remote from the connecting rod 5 and the crank pin 7 is a further crank pin 11 on which a further connecting rod 12 is mounted. The other end of the connecting rod 12 is connected by way of a pin 13 to a counterweight 14. The counterweight 14 is mounted for axial displacement on a guide rod 15.

The longitudinal axis of the guide rod 1 5 is aligned with the longitudinal axis of tslider member 1.

The crank disc 8 IS engaged by way of its external teeth 10 with a drive pinion 16 of a drive (not shown), preferably an electric motor.

As, when the counterweight 14 moves in opposite directions with respect to the slider member 1, the counterweight 14 is guided in a line which is in alignment with the longitudinal axis of the slider member 1, longitudinal oscillations of the saw are virtually completely eliminated. If there are any transverse oscillations at all, such oscillations are of a degree which is only insignificant from the practical point of view, as the two connecting rods 5 and 12 are only slightly offset relative to each other.

A further advantage is that the housing 4 can be made small and flat.

Claims

1. A saw having a slider member which can be reciprocated by a connecting rod and to which a saw blade may be secured, and a counterweight which is movable by a further connecting rod in opposition to the slider member, wherein the connecting rods are mounted on two opposite sides of a crank disc which is provided with external teeth and which is rotatably mounted in a drive housing in a bearing and which is engaged by means of its external teeth with a drive pinion.

2. A saw according to claim 1, wherein the longitudinal axis of a guide rod on which the counterweight is guided for displacement is

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Saw The present invention relates to a driven saw particularly such a saw in which a reciprocating blade is held at one end. Among the saws to which the application is applicable are compass saws, fretsaws, keyhole saws and tenon-saws. Saws have been proposed having a slider member which can be moved up and down by a connecting rod and to which a saw blade may be secured, and a counterweight which is movable by a further connecting rod, in opposition to the slider member. Providing a counterweight for the slider member and the saw blade is intended to cause the oscillations which occur in operation, due to the upward and downward movements of the slider member with the saw blade, to be nullified or substantially eliminated. Hitherto, the two connecting rods have been connected to a crankshaft. The mounting for the crankshaft is relatively expensive and the crankshaft itself is a complicated and also large component. This has a hightly detrimental effect both in regard to manufacturing costs and also the dimensions of the saw. Furthermore, in the previously proposed saws, it is inevitable that considerable transverse oscillations occur due to the relatively large distance between the connecting rods, so that in many cases the desired effect, namely reducing longitudinal oscillations by the provision of a counterweight, is nullified by the transverse oscillations which are produced. There is therefore a need for a saw of the kind set out above, which is of small dimensions and which has low manufacturing costs, and in which oscillations do not occur or oscillations occur to an extent which is of no significance from the practical point of view. According to the present invention, there is provided a saw having a slider member which can be reciprocated by a connecting rod and to which a saw blade may be secured, and a counterweight which is movable by a further connecting rod in opposition to the slider member, wherein the connecting rods are mounted on two opposite sides of a crank disc which is provided with external teeth and which is rotatably mounted in a drive housing in a bearing and which is engaged by means of its external teeth with a drive pinion. Using a crank disc which is mounted only in a bearing such as a ball bearing assembly provides a considerable reduction both in manufacturing costs and also in the overall dimensions of the drive unit of the saw, and also provides that the two connecting rods are spaced from each other by only a very small distance, so that transverse oscillations do not occur, or occur only to an insignificant extent, in operation of the saw. An embodiment of the invention is described in greater detail hereinafter by way of example with reference to the drawing in which:~ Figure 1 shows a view in longitudinal section through a drive housing of a power-driven compass saw according to the invention, including the saw blade, but without showing a drive motor, and Figure 2 shows a view in the direction of the arrow II in Figure 1, with the cover of the drive housing removed. Figures 1 and 2 show the main components of a compass saw according to the invention. A saw blade 2 is secured to a slider member 1 which is mounted for axial displacement in a bush 3 which is fitted into an end wall of a drive housing 4. A connecting rod 5 is connected by way of a pin 6 to the end of the slider member 1 which projects into the interior of the housing 4. The connecting rod 5 is connected by its other end to a crank pin 7 which in turn is secured to a crank disc 8. The crank disc 8 is mounted rotatably in a ball or roller bearing assembly 9 within the housing 4 and is provided with external teeth 10. At the side of the crank disc 8 which is remote from the connecting rod 5 and the crank pin 7 is a further crank pin 11 on which a further connecting rod 12 is mounted. The other end of the connecting rod 12 is connected by way of a pin 13 to a counterweight 14. The counterweight 14 is mounted for axial displacement on a guide rod 15. The longitudinal axis of the guide rod 1 5 is aligned with the longitudinal axis of tslider member 1. The crank disc 8 IS engaged by way of its external teeth 10 with a drive pinion 16 of a drive (not shown), preferably an electric motor. As, when the counterweight 14 moves in opposite directions with respect to the slider member 1, the counterweight 14 is guided in a line which is in alignment with the longitudinal axis of the slider member 1, longitudinal oscillations of the saw are virtually completely eliminated. If there are any transverse oscillations at all, such oscillations are of a degree which is only insignificant from the practical point of view, as the two connecting rods 5 and 12 are only slightly offset relative to each other. A further advantage is that the housing 4 can be made small and flat. Claims
1. A saw having a slider member which can be reciprocated by a connecting rod and to which a saw blade may be secured, and a counterweight which is movable by a further connecting rod in opposition to the slider member, wherein the connecting rods are mounted on two opposite sides of a crank disc which is provided with external teeth and which is rotatably mounted in a drive housing in a bearing and which is engaged by means of its external teeth with a drive pinion.
2. A saw according to claim 1, wherein the longitudinal axis of a guide rod on which the counterweight is guided for displacement is aligned with the longitudinal axis of the slider member.
3. A saw substantially as described herein with reference to the accompanying drawings.
GB7909160A 1979-03-15 1979-03-15 Saw Withdrawn GB2042973A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7909160A GB2042973A (en) 1979-03-15 1979-03-15 Saw

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB7909160A GB2042973A (en) 1979-03-15 1979-03-15 Saw

Publications (1)

Publication Number Publication Date
GB2042973A true true GB2042973A (en) 1980-10-01

Family

ID=10503901

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7909160A Withdrawn GB2042973A (en) 1979-03-15 1979-03-15 Saw

Country Status (1)

Country Link
GB (1) GB2042973A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2203810A (en) * 1987-04-13 1988-10-26 Michael Bains A mechanism for translating between rotary and reciprocating motion
GB2249751A (en) * 1990-11-13 1992-05-20 Milwaukee Electric Tool Corp Counterbalanced recipocating mechanism.
FR2678038A1 (en) * 1990-03-01 1992-12-24 Milwaukee Electric Tool Corp Balanced drive mechanism and pad saw
US5566458A (en) * 1994-12-13 1996-10-22 Milwaukee Electric Tool Corporation Clutch mechanism for reciprocating saws
US5607023A (en) * 1994-12-13 1997-03-04 Milwaukee Electric Tool Corp. Impact absorption mechanism for power tools
US5689891A (en) * 1994-12-13 1997-11-25 Milwaukee Electric Tool Corp. Clutch mechanism for reciprocating saws
USRE37211E1 (en) 1994-12-13 2001-06-12 Milwaukee Electric Tool Corporation Clutch mechanism for reciprocating saws
US6286217B1 (en) 1998-04-09 2001-09-11 Black & Decker Inc. Reciprocating saw with pivoted arm drive
US7562457B2 (en) * 2006-11-07 2009-07-21 Acu-Cutter Corp. Foam cutter blade attachment device
US7814666B2 (en) * 2007-02-13 2010-10-19 Robert Bosch Gmbh Linkage drive mechanism for a reciprocating tool

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2203810A (en) * 1987-04-13 1988-10-26 Michael Bains A mechanism for translating between rotary and reciprocating motion
FR2678038A1 (en) * 1990-03-01 1992-12-24 Milwaukee Electric Tool Corp Balanced drive mechanism and pad saw
GB2249751A (en) * 1990-11-13 1992-05-20 Milwaukee Electric Tool Corp Counterbalanced recipocating mechanism.
GB2249751B (en) * 1990-11-13 1994-03-09 Milwaukee Electric Tool Corp Counterbalanced reciprocating mechanism
USRE35258E (en) * 1990-11-13 1996-06-04 Milwaukee Electric Tool Corporation Counterbalanced reciprocating mechanism
DE4108984C2 (en) * 1990-11-13 2000-10-05 Milwaukee Electric Tool Corp Balanced pendulum mechanism
US5689891A (en) * 1994-12-13 1997-11-25 Milwaukee Electric Tool Corp. Clutch mechanism for reciprocating saws
US5607023A (en) * 1994-12-13 1997-03-04 Milwaukee Electric Tool Corp. Impact absorption mechanism for power tools
US5566458A (en) * 1994-12-13 1996-10-22 Milwaukee Electric Tool Corporation Clutch mechanism for reciprocating saws
USRE37211E1 (en) 1994-12-13 2001-06-12 Milwaukee Electric Tool Corporation Clutch mechanism for reciprocating saws
USRE38606E1 (en) * 1994-12-13 2004-10-05 Milwaukee Electric Tool Corporation Clutch mechanism for reciprocating saws
USRE37529E1 (en) 1994-12-13 2002-01-29 Milwaukee Tool Corporation Clutch mechanism for reciprocating saws
US6286217B1 (en) 1998-04-09 2001-09-11 Black & Decker Inc. Reciprocating saw with pivoted arm drive
US7562457B2 (en) * 2006-11-07 2009-07-21 Acu-Cutter Corp. Foam cutter blade attachment device
US7814666B2 (en) * 2007-02-13 2010-10-19 Robert Bosch Gmbh Linkage drive mechanism for a reciprocating tool

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)