CN113246228A

CN113246228A - Chain saw

Info

Publication number: CN113246228A
Application number: CN202110392419.6A
Authority: CN
Inventors: 陈洁
Original assignee: Zhejiang YAT Electrical Appliance Co Ltd
Current assignee: Zhejiang YAT Electrical Appliance Co Ltd
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2021-08-13
Anticipated expiration: 2041-04-13
Also published as: CN113246228B

Abstract

The invention discloses a chain saw, which comprises a machine shell, a chain plate, a saw chain and a tensioning and locking device, wherein the tensioning and locking device comprises a cam, a push plate, a first elastic part and a driving assembly; the driving assembly is connected with the cam, a spiral groove is formed in the cam, a protrusion matched with the spiral groove is formed in the push plate and extends into the spiral groove, the push plate is connected with the chain plate, and the driving assembly moves to drive the cam to rotate so as to drive the push plate to move along a straight line. When the chain saw is applied to the working process of the chain saw, even if the saw chain is subjected to large instant impact force, the chain plate cannot generate displacement under the action of the push plate due to the clamping of the interaction between the spiral groove and the protrusion, so that the saw chain can keep the tension degree, the times of tension adjustment operation are effectively reduced, and the service life of the chain saw is prolonged.

Description

Chain saw

Technical Field

The invention belongs to the field of garden tools, and particularly relates to a chain saw.

Background

A chain saw is a commonly used gardening tool, and is commonly used for cutting materials such as wood, stone and the like. The material is cut continuously by a saw chain which needs to run circularly in the cutting part, and the tightness of the saw chain needs to be adjusted in the process of mounting the saw chain on the machine shell, so that a better cutting effect can be obtained. And during the cutting operation, the saw chain can be loosened due to abrasion and thermal expansion, and the tightness of the saw chain also needs to be adjusted. The operation of above-mentioned regulation rate of tension needs the operator oneself manual regulation, can have certain operation requirement to the operator like this, and ordinary consumer hardly grasps this regulation dynamics in operation process to still need hand-carry adjustment tool, very inconvenient.

Therefore, the market starts to produce a design for realizing automatic tensioning by using an elastic body, in particular, when the saw chain is loosened a little, the elastic force of the elastic body is used for driving the chain plate for fixing the saw chain to move forwards, and the saw chain is driven to be tensioned again. However, the following problems exist in the practical use of this design: even if the chain plate is fixed on the shell by the fastening piece, the chain plate for fixing the saw chain can still be displaced due to overlarge instant impact force on the saw chain during cutting operation, so that the chain plate returns relative to the chain wheel, and the saw chain is loosened again. Therefore, the chain saw with the structure always needs to be repeatedly tensioned and adjusted for multiple times in the using process, the operation is inconvenient, and the service life of the chain saw is influenced.

Disclosure of Invention

The invention aims to provide a chain saw which can effectively solve the problem that a chain plate is displaced due to instant impact force when in use so as to loosen a saw chain, and can also conveniently and quickly adjust the tension degree after the saw chain is loosened due to long-time work.

In order to solve the technical problems, the invention adopts the following technical scheme: a chain saw comprises a machine shell, a chain plate, a saw chain and a tensioning and locking device, wherein the tensioning and locking device comprises a cam, a push plate, a first elastic piece and a driving assembly, the first elastic piece is connected between the machine shell and the driving assembly, and the first elastic piece is used for driving the driving assembly to move; the driving assembly is connected with the cam, a spiral groove is formed in the cam, a protrusion matched with the spiral groove is formed in the push plate, the protrusion extends into the spiral groove, the push plate is connected with the chain plate, and the driving assembly moves to drive the cam to rotate so as to drive the push plate to move along a straight line.

Preferably, the cam comprises a disc, a guide shaft penetrates through the center of the disc, the spiral groove is formed in one side, facing the push plate, of the disc around the guide shaft, a long groove or a long hole into which the guide shaft is inserted is formed in the push plate, and the length direction of the long groove or the long hole is consistent with the length direction of the chain plate. When the cam rotates, the inner wall of the spiral groove is different from the center of rotation, the inner wall of the spiral groove pushes the protrusion, and the guide shaft is matched with the long groove or the long hole to limit the push plate, so that the push plate can only move along the length direction of the long groove or the long hole, and can act on the chain plate to tension the saw chain.

Preferably, the disc deviates from one side center of push pedal and is equipped with the gear, drive assembly includes the drive plate, be equipped with on the drive plate with the rodent of gear engagement, first elastic component is connected between drive plate and casing. The cam is driven to rotate by the driving plate in a gear meshing transmission mode, and the gear meshing transmission precision is high and is not easy to damage. The first elastic piece is connected between the shell and the drive plate, and when the tension degree needs to be adjusted, the drive plate is driven to move by the aid of elasticity of the first elastic piece, and then the cam is driven to rotate.

Preferably, the drive plate swing is connected on the casing, the drive plate includes the arc limit, the rodent has been seted up on the arc limit, the centre of a circle of arc limit radian and drive plate swing motion's center coincidence. Compared with the linear motion, the track of the rodent is arc-shaped during swinging, the meshing frequency with the gear is more, the driving efficiency is higher, and further, the occupied space is smaller.

Preferably, a swing shaft is arranged on the machine shell, the drive plate is sleeved on the swing shaft and swings around the swing shaft, a limiting protrusion is arranged on the swing shaft, a clamping groove matched with the limiting protrusion is formed in the drive plate, and the limiting protrusion and the clamping groove are matched to limit the drive plate. When the chain plate needs to be installed, the elastic force of the first elastic piece is overcome firstly, the drive plate swings and drives the push plate to move backwards, so that the installation position of the chain plate is vacated, and after the drive plate swings in place, the position of the drive plate is locked by the aid of the limiting protrusions and the clamping grooves in a matched mode, an operator does not need to control the position of the drive plate by hands all the time, and the chain plate is convenient to install by one person.

Preferably, be equipped with first holding tank on the casing, the oscillating axle is installed in first holding tank along endwise slip, be equipped with the second elastic component in the first holding tank, the second elastic component is arranged in promoting the oscillating axle so that spacing arch card goes into the draw-in groove. Therefore, the driving plate can be automatically clamped into the clamping groove by the limiting protrusion under the action of the second elastic piece only by swinging in place, and the use is convenient.

Preferably, the driving plate is connected to the housing in a reciprocating sliding manner along a straight line.

Preferably, be equipped with limit button on the drive plate, be equipped with the spacing hole with limit button looks adaptation on the casing, be equipped with the second holding tank on the drive plate, limit button sliding connection is in the second holding tank, be equipped with the third elastic component in the second holding tank, the third elastic component is arranged in promoting limit button so that limit button card goes into spacing hole. Therefore, as long as the driving plate is moved in place, the limiting button is automatically clamped into the limiting hole under the action of the third elastic piece, and the use is convenient.

Preferably, a chain wheel is arranged in the machine shell, a gap is formed between the chain wheel and the chain plate, a top column extending into the gap is arranged on the push plate, and the top column is connected with the chain plate and used for pushing the chain plate to move forwards. Because the long groove or the long hole is required to be arranged on the push plate to be matched with the guide shaft to limit the push plate to move along a straight line, the push plate must have a certain length along the moving direction of the chain plate, if the push plate and the chain plate are directly arranged on the same plane, the push plate is directly positioned between the chain wheel and the chain plate, a large space is occupied, and the push plate also needs a space for moving back and forth. Therefore, the top column is arranged to extend into the gap between the chain wheel and the chain plate, and the occupied space can be effectively reduced.

Preferably, the machine shell is provided with a pressing knob and a bolt, the chain plate is provided with a long circular hole for the bolt to pass through, the length direction of the long circular hole is consistent with that of the chain plate, and the bolt passes through the long circular hole and is in threaded connection with the pressing knob. The chain plate is fixed through the pressing knob, when the tension degree needs to be adjusted, the pressing knob is loosened, the elastic force of the elastic piece is utilized to enable the push plate to drive the chain plate to move, and due to the fact that the long round holes are formed, the bolts cannot influence the movement of the chain plate.

Compared with the prior art, the invention has the following beneficial effects:

1. when the chain saw is loosened due to abrasion and heating expansion after working for a long time, the driving assembly can be driven by the first elastic piece to drive the cam to rotate, the cam drives the push plate to move through the matching of the spiral groove and the bulge, and the push plate pushes the chain plate to move forwards, so that the chain plate drives the saw chain to be tensioned relative to the chain wheel, an adjusting tool does not need to be additionally carried, and the operation of a user is facilitated;

2. after the tension of the saw chain is adjusted in place, in the working process of the chain saw, even if the saw chain is subjected to large instant impact force, due to the clamping of the spiral groove and the protrusion, the chain plate cannot generate displacement under the action of the push plate, so that the tension of the saw chain can be maintained, the times of tensioning adjustment operation can be effectively reduced, and the service life of the chain saw is prolonged.

Drawings

FIG. 1 illustrates an exploded view of a chain saw according to one embodiment;

FIG. 2 is an exploded view of the drive assembly, cam and support plate of the first embodiment

FIG. 3 is a schematic structural diagram of a cam according to the first embodiment;

FIG. 4 illustrates a cross-sectional view of a chain saw provided in accordance with an embodiment of the present invention during installation of a link plate;

FIG. 5 illustrates a cross-sectional view of the chain saw with tension adjustment;

fig. 6 is an exploded view of the drive assembly, cam and support plate of the second embodiment.

Wherein: 1. the novel saw comprises a machine shell, 10 parts of a main shell, 100 parts of bolts, 11 parts of side covers, 110 parts of pressing knobs, 111 parts of through holes, 12 parts of a cover body, 13 parts of a supporting plate, 130 parts of swing shafts, 1300 parts of limiting protrusions, 131 parts of first accommodating grooves, 132 parts of second elastic pieces, 133 parts of strip-shaped holes, 2 parts of chain wheels, 3 parts of chain plates, 30 parts of long round holes, 4 parts of saw chains, 5 parts of cams, 50 parts of circular discs, 51 parts of spiral grooves, 52 parts of gears, 53 parts of guide shafts, 6 parts of push plates, 60 parts of protrusions, 61 parts of long holes, 62 parts of top columns, 7 parts of first elastic pieces, 8 parts of driving assemblies, 80 parts of driving plates, 800 parts of toggle buttons, 801 parts of limiting buttons, 802 parts of second accommodating grooves and 803 parts of third elastic pieces.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are intended to be inclusive and mean that, for example, they may be fixedly connected or detachably connected or integrally formed; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The first embodiment is as follows: as shown in fig. 1, 2 and 3, the chain saw provided by this embodiment includes a housing 1, a sprocket 2, a chain plate 3 and a saw chain 4, where the housing 1 includes a main housing 10, a cover body 12 disposed on one side of the main housing 10 and a side cover 11 disposed on the other side of the main housing 10, the sprocket 2 is disposed in an accommodating cavity formed by the main housing 10 and the side cover 11, a rear end of the chain plate 3 is also disposed in the accommodating cavity, the saw chain 4 surrounds the sprocket 2 and the chain plate 3, the sprocket 2 is driven by a power source to rotate, and the sprocket 2 drives the saw chain 4 to perform a cutting action. The power source is disposed between the main housing 10 and the housing 12, and the power source in this embodiment is a motor, that is, the chain saw is an electric chain saw, it is understood that the chain saw may be other power chain saws, such as a chain saw or a hydraulic chain saw. The chain saw in this embodiment further includes a tensioning locking device, the tensioning locking device includes a cam 5, a push plate 6, a first elastic member 7 and a driving assembly 8, the first elastic member 7 is connected between the housing 1 and the driving assembly 8, the first elastic member 7 is used for driving the driving assembly 8 to move, in this embodiment, the first elastic member 7 is a spring, and it can be understood that the first elastic member may also be a common elastic member such as a spring plate. Drive assembly 8 is connected with cam 5, and cam 5 includes disc 50, and guiding axle 53 is worn to be equipped with in disc 50 center, and disc 50 has seted up helicla flute 51 around guiding axle 53 towards one side of push pedal 6, is equipped with the arch 60 with helicla flute 51 looks adaptation on the push pedal 6, and arch 60 stretches into in the helicla flute 51, and push pedal 6 is connected with

link joint

3, and 8 movements of drive assembly are used for drive cam 5 to rotate in order to drive push pedal 6 along rectilinear movement.

Specifically, in the present embodiment, the push plate 6 is provided with a long hole 61 into which the guide shaft 53 is inserted, and the long hole 61 may be a long groove, and the longitudinal direction of the long hole 61 coincides with the longitudinal direction of the link plate 3. The protrusion 60 extends into the spiral groove 51, when the cam 5 rotates, because the distance between the inner wall of the spiral groove 51 and the center of rotation is different, the inner wall of the spiral groove 51 pushes the protrusion 60, and the push plate 6 is limited by the matching of the guide shaft 53 and the long groove or the long hole 61, so that the push plate 6 can only move along the length direction of the long groove or the long hole 61, and can act on the chain plate 3 to tension the saw chain 4. If the push plate 6 is directly arranged on the same plane as the chain plate 3, the push plate 6 is directly arranged between the chain wheel 2 and the chain plate 3, because the push plate 6 is long (because the push plate 6 needs to be provided with an elongated slot or a long hole 61 to be matched with the guide shaft 53 for limiting the push plate 6 to move along a straight line, the push plate 6 must have a certain length along the moving direction of the chain plate 3), and the push plate 6 also needs to move in a space, which causes a long gap to be left between the chain wheel 2 and the chain plate 3, and occupies a large space, so that the push plate 6 is also provided with the top column 62 below. Specifically, casing 1 in this embodiment includes backup pad 13, and push pedal 6 sliding connection has seted up bar hole 133 in backup pad 13 on the backup pad 13, and the length direction in bar hole 133 is unanimous with the length direction of link joint 3, and the fore-set 62 that sets up on push pedal 6 wears to establish bar hole 133 and stretches into the clearance between link joint 3 and the sprocket 2 and is connected with link joint 3, so can be very good save space.

The driving assembly 8 in this embodiment includes a driving plate 80, the driving plate 80 is installed on the supporting plate 13, a gear 52 is disposed in the center of one side of the disk 50 away from the push plate 6, a tooth meshed with the gear 52 is disposed on the driving plate 80, the first elastic member 7 is a spring, one end of the spring is connected to the housing 1, and the other end of the spring is connected to the driving plate 80. The cam 5 is driven to rotate by the driving plate 80 through the meshing transmission mode of the gear 52, and the meshing transmission precision of the gear 52 is high and is not easy to damage. The first elastic member 7 is connected between the casing 1 and the driving plate 80, and when the tension degree needs to be adjusted, the elastic force of the first elastic member 7 is used for driving the driving plate 80 to move, so that the cam 5 is driven to rotate. In this embodiment, the drive board 80 is further provided with a toggle button 800, and the side cover 11 is provided with a through hole 111 for the toggle button 800 to move, so that the drive board 80 can be directly driven to move by operating the fluctuation button when in use. In addition, it can be understood that, when the installation of the link plate 3 and the saw chain 4 and the tension adjustment are completed, the state of the first elastic member 7 may be either a tensile state or a compression state, as long as the first elastic member 7 is configured to push the link plate 3 forward to tension the saw chain 4.

Drive plate 80 includes the arc limit in this embodiment, has seted up on the arc limit the rodent, the centre of a circle of arc limit radian and the center coincidence of drive plate swing motion, specifically, be equipped with swing axle 130 on backup pad 13, drive plate 80 cover is established on swing axle 130 and is swung around swing axle 130. Compared with the linear motion, the track of the rodent is arc-shaped during swinging, so that the meshing frequency with the gear 52 is more, the driving efficiency is higher, and the occupied space is smaller. In this embodiment, the swing shaft 130 is further provided with a limiting protrusion 1300, the driving plate 80 is provided with a locking groove (not shown in the figure) adapted to the limiting protrusion 1300, the supporting plate 13 is provided with a first accommodating groove 131 for accommodating the swing shaft 130, the swing shaft 130 is slidably mounted in the first accommodating groove 131, the first accommodating groove 131 is provided with a second elastic member 132, and the second elastic member 132 is used for pushing the swing shaft 130 to lock the limiting protrusion 1300 into the locking groove. When the chain plate 3 needs to be installed, the elastic force of the first elastic part 7 is overcome firstly, the driving plate 80 swings and drives the push plate 6 to move backwards, so that the installation position of the chain plate 3 is vacated, after the driving plate 80 swings in place, the limiting protrusion 1300 is automatically clamped into the clamping groove under the action of the second elastic part 132, the position of the driving plate 80 is locked by the matching of the limiting protrusion 1300 and the clamping groove, an operator does not need to control the position of the driving plate 80 by hands all the time, and the chain plate 3 is convenient to install by a single person.

The casing 1 in this embodiment further includes a side cover 11, a pressing knob 110 is provided on the side cover 11, a bolt 100 is provided on the casing 1, an oblong hole 30 through which the bolt 100 passes is provided on the link plate 3, a length direction of the oblong hole 30 is identical to a length direction of the link plate 3, and the bolt 100 passes through the oblong hole 30 and is in threaded connection with the pressing knob 110. The chain plate 3 is fixed through the pressing knob 110, when the tension degree needs to be adjusted, the pressing knob 110 is loosened, the push plate 6 drives the chain plate 3 to move by utilizing the elasticity of the elastic part, and the connecting section cannot influence the movement of the chain plate 3 due to the arrangement of the long circular hole 30.

The mounting and tension adjustment operation of the chain saw provided using the present embodiment is described as follows: referring to fig. 4, when the chain plate 3 and the saw chain 4 need to be installed, an operator firstly dials the toggle button 800 to overcome the elasticity of the first elastic element 7, so that the drive plate 80 swings, the drive plate 80 swings and then drives the cam 5 to rotate through the meshing transmission of the gear 52, the cam 5 rotates and drives the push plate 6 to move backwards by utilizing the matching of the spiral groove 51 and the protrusion 60, so that the top post 62 moves backwards to leave the position of the front end for installing the chain plate 3 and the saw chain 4, and when the drive plate 80 swings in place, the limiting protrusion 1300 is clamped into the clamping groove under the action of the second elastic element 132 to fix the position of the drive plate 80. The operator then mounts the link plate 3 to the main housing 10 and encloses the saw chain 4 around the sprocket 2 and the link plate 3. As shown in fig. 5, the swing shaft 130 is pressed against the elastic force of the second elastic member 132 to separate the limiting protrusion 1300 from the slot, so that the driving plate 80 swings reversely under the elastic force of the first elastic member 7, and the top pillar 62 is driven to move forward according to the above principle, and the top pillar 62 pushes the link plate 3 to move forward until the saw chain 4 is tensioned. Finally, the side cover 11 is covered on the main housing 10, and the chain plate 3 is fixed with the machine shell 1 by using the pressing knob 110. After the tension of the saw chain 4 is adjusted in place, in the working process of the chain saw, even if the saw chain 4 is subjected to large instant impact force, due to the interaction between the spiral groove 51 and the protrusion 60, the chain plate 3 cannot generate displacement under the action of the push plate 6, so that the saw chain 4 can keep the tension, the times of tensioning adjustment operation are effectively reduced, and the service life of the chain saw is prolonged. When the saw chain 4 is loosened due to abrasion and thermal expansion after the chain saw works for a long time, the pressing knob 110 can be unscrewed, so that the driving plate 80 swings under the elastic force of the first elastic piece 7 to drive the cam 5 to rotate, further drive the push plate 6 to move forwards, the push plate acts on the chain plate 3 through the top column 62, the chain plate 3 moves forwards to tension the saw chain 4, and then the pressing knob 110 is screwed. The adjusting tool does not need to be additionally carried, and the operation of a user is convenient.

Example two: the present embodiment also provides a chain saw, which is different from the above embodiments in that the driving assembly 8 of the present embodiment is arranged differently from the driving assembly 8 of the above embodiments, specifically, as shown in fig. 6, the driving plate 80 of the present embodiment is connected to the housing 1 in a linear reciprocating sliding manner, and the rodent is arranged in a linear track.

Based on the above distinguishing technical features, the cam 5 is driven to rotate by the driving plate 80 moving along a straight line in the embodiment. In addition, the driving board 80 in this embodiment is further provided with a limit button 801, the side cover 11 is provided with a limit hole (not shown in the figure) adapted to the limit button 801, the driving board 80 is provided with a second receiving groove 802, the limit button 801 is slidably connected in the second receiving groove 802, the second receiving groove 802 is provided with a third elastic member 803, and the third elastic member 803 is used for pushing the limit button 801 so that the limit button 801 is clamped into the limit hole. In this embodiment, the through hole formed in the side cover 11 for sliding the toggle button 800 may communicate with the limiting hole, as long as the width of the through hole is smaller than that of the limiting button 801, so that the number of holes formed in the side cover 11 may be reduced.

With the chain saw provided by the embodiment, in the process of operation of installing the chain plate 3, when the driving plate 80 slides in place along a straight line, the limiting button 801 is bounced up and pushed into the limiting hole under the action of the third elastic member 803, so that the position of the driving plate 80 is fixed.

The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto, and any changes or modifications within the scope of the present invention by those skilled in the art are covered by the present invention.

Claims

1. A chain saw comprises a machine shell, a chain plate and a saw chain, and is characterized in that: the tensioning and locking device comprises a cam, a push plate, a first elastic piece and a driving assembly, wherein the first elastic piece is connected between the shell and the driving assembly and is used for driving the driving assembly to move;

the driving assembly is connected with the cam, a spiral groove is formed in the cam, a protrusion matched with the spiral groove is formed in the push plate, the protrusion extends into the spiral groove, the push plate is connected with the chain plate, and the driving assembly moves to drive the cam to rotate so as to drive the push plate to move along a straight line.

2. A chain saw as recited in claim 1, wherein: the cam comprises a disc, a guide shaft penetrates through the center of the disc, the spiral groove is formed in one side, facing the push plate, of the disc around the guide shaft, a long groove or a long hole into which the guide shaft is inserted is formed in the push plate, and the length direction of the long groove or the long hole is consistent with the length direction of the chain plate.

3. A chain saw as recited in claim 2, wherein: the disc deviates from one side center of push pedal and is equipped with the gear, drive assembly includes the drive plate, be equipped with on the drive plate with gear engagement's rodent, first elastic component is connected between drive plate and casing.

4. A chain saw as recited in claim 3, wherein: the drive plate swing joint is on the casing, the drive plate includes the arc limit, the arc edge has been seted up the rodent, the centre of a circle of arc limit radian and drive plate swing motion's center coincidence.

5. A chain saw as set forth in claim 4 wherein: the motor is characterized in that a swing shaft is arranged on the shell, the drive plate is sleeved on the swing shaft and swings around the swing shaft, a limiting bulge is arranged on the swing shaft, a clamping groove matched with the limiting bulge is formed in the drive plate, and the limiting bulge and the clamping groove are matched to limit the drive plate.

6. A chain saw as set forth in claim 5 wherein: be equipped with first holding tank on the casing, the oscillating axle is installed in first holding tank along endwise slip, be equipped with the second elastic component in the first holding tank, the second elastic component is arranged in promoting the oscillating axle so that spacing protruding card goes into the draw-in groove.

7. A chain saw as recited in claim 3, wherein: the driving plate is connected to the machine shell in a reciprocating sliding mode along a straight line.

8. A chain saw as set forth in claim 7 wherein: be equipped with limit button on the drive plate, be equipped with the spacing hole with limit button looks adaptation on the casing, be equipped with the second holding tank on the drive plate, limit button sliding connection is in the second holding tank, be equipped with the third elastic component in the second holding tank, the third elastic component is arranged in promoting limit button so that limit button card goes into spacing hole.

9. A chain saw as recited in claim 1, wherein: the chain wheel is arranged in the shell, a gap is formed between the chain wheel and the chain plate, a top column extending into the gap is arranged on the push plate, and the top column is connected with the chain plate and used for pushing the chain plate to move forwards.

10. A chain saw as recited in claim 1, wherein: the chain plate is provided with a long circular hole for the bolt to pass through, the length direction of the long circular hole is consistent with that of the chain plate, and the bolt passes through the long circular hole and is in threaded connection with the pressing knob.