JP2544219B2 - Automatic lifting platform - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is designed so that, when a large number of identical articles having a constant weight are loaded on a bed, the height of the uppermost article is substantially constant.
The present invention relates to an automatic lifting platform that automatically moves up and down according to a load.

(Prior Art) This type of automatic lifting / lowering platform has a loading platform supported by a frame so as to be able to move up and down, and a tension spring for urging the loading platform in an upward direction between the loading platform and the frame. Various types are known, but when the weight of an article to be handled changes, the height of the uppermost article can be kept substantially constant unless the lifting force of the platform by the tension spring is adjusted. Can not. Therefore, it is necessary to adjust the loading platform pulling force. In the conventional automatic lifting platform, the tension spring, for example, the frame side end position can be directly adjusted by a screw mechanism, or As disclosed in Japanese Patent Publication No. 50-1062,
The inclination angle of the cam rail for tensioning and loosening the tension spring as the platform is moved up and down can be adjusted by a screw mechanism.

(Problems to be Solved by the Invention) In the conventional loading platform lifting force adjusting mechanism as described above, there is an advantage that the loading platform lifting force can be adjusted steplessly according to the load, but in the former direct adjusting mechanism, the adjustment amount is Since it becomes large, it takes time and effort to adjust, and in the latter indirect adjustment mechanism, the structure becomes complicated and the cost becomes high, and the whole device becomes heavy, and the tension of the tension spring does not act directly on the bed. Therefore, there is a drawback that the loading platform does not react sensitively to changes in load, and the loading platform height easily varies.

(Means for Solving the Problems) In order to solve the above-mentioned conventional problems, the present invention provides a loading platform that is supported by a frame so as to be able to move up and down, and the loading platform in the ascending direction between the loading platform and the frame. In an automatic hoisting platform having a tension spring for urging the tension spring, a plurality of the tension springs are arranged side by side, and at least one tension spring is releasably locked to the frame by a movable locking member. A spring receiver supporting portion that engages the spring receiver and that supports the spring receiver at a fixed position when the luggage carrier is at the upper limit position, the luggage carrier is provided with the movable retainer. It proposes an automatic lifting platform which is rotatably attached to either one of a frame and a platform, and on the other side of which is provided a locked portion to which the locking claw of the movable locking tool can be engaged and disengaged. is there.

(Example) Hereinafter, one example of the present invention will be described with reference to the accompanying drawings.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a carrier truck that is movable on the floor surface. A rectangular frame-shaped frame 2 is vertically installed upright at the rear end, and the frame 2 has a rear end near the upper end. A hand push handle 3 is attached. A loading platform 4 is a vertical base 7 supported by a pair of left and right elevating guide rail portions 2a, 2b of the frame 2 so as to be able to ascend and descend via a front-rear direction positioning roller 5 and a left-right lateral positioning roller 6.
And a loading section 8 projecting forward from the lower end of the vertical base section 7 in a cantilever manner. 9a, 9b and 10a ~
Reference numeral 10c is a tension spring stretched between the vertical base 7 of the cargo bed and the upper horizontal frame 2c of the frame 2.

As shown in FIGS. 3 and 4, the loading platform vertical base 7 is shown.
Is a pair of left and right side plates 11a and 11b that pivotally support the rollers 5 and 6,
A pair of front and rear connecting plates 12a, 12b installed between the upper ends of the both side plates 11a, 11b, a connecting plate 13 installed between the rear sides near the lower ends of the both side plates 11a, 11b, and the both side plates 11a, The horizontal rod 14 is provided between the lower ends of 11b, and the lower ends of the tension springs 9a to 10c are locked to the horizontal rod 14.

Of the tension springs 9a to 10c, the upper ends of the tension springs 9a and 9b at both ends are the upper end horizontal frame portion 2c of the frame 2.
It is locked to the brackets 15a and 15b fixed to the
The upper ends of the two tension springs 10a to 10c are connected to the frame 2
Is locked via gates 18a to 18c to gate-shaped spring receivers 17a to 17c that are removably locked to the upper horizontal frame portion 2c by movable locking members 16a to 16c. In addition, as shown in FIG. 1, the connecting plates 11a and 11b of the loading platform vertical base 7 have the gate-shaped spring receivers 17a to 17c when the loading platform 4 (loading platform vertical base 7) is at the upper limit position. V-shaped recessed spring receiver support portions 19a to 19c that fit in place
Is provided. Reference numerals 20a to 20d are projection-shaped positioning guides for positioning the spring receivers 17a to 17c in the lateral direction when the loading platform 4 (the loading platform vertical base portion 7) is raised to the upper limit position as shown in FIG. Then, it is provided so as to project below the upper horizontal frame portion 2c of the frame 2.

As shown in FIGS. 5 to 7, the movable locking members 16a to 16c are provided.
Is a rotatable shaft 21 that vertically penetrates the upper horizontal frame 2c of the frame 2, a cap portion 22 fixed to the upper end of the shaft 21, and a rectangular shape fixed to the lower end of the shaft 21. Locking claw 23, the cap portion 22, the upper frame horizontal frame portion
Torsion coil spring 24 loosely fitted to shaft 21 between 2c
The torsion coil spring 24 has one end 24a locked to the frame upper end horizontal frame portion 2c and the other end 24b locked to the cap portion 22 to allow the shaft 21 (locking claw 23 ) Is urged in the direction opposite to the arrow 25 in FIG. 6 and simultaneously in the upward direction. Reference numeral 26 is a rotation operation groove formed in the upper ends of the cap portion 22 and the shaft 21, and 27 is a rotation stop stopper for the locking claw 23 that projects downward from the frame upper end horizontal frame portion 2c. In addition, the upper horizontal frame of the frame
When the locking claw 23 is rotated in the front-rear direction by the torsional biasing force of the torsion coil spring 24 and comes into contact with the stopper 27, the downward direction of the torsion coil spring 24 A shallow recess 28 is formed which is fitted by receiving a force.

As shown in FIGS. 8 and 9, the gate-shaped spring receivers 17a to 17c have a through hole 29 in the front wall direction through which the locking claw 23 and the stopper 27 can pass. The upper wall around the through hole 29 is provided with the locking claw.
23 is the locked portion 30.

Next, the method of use and operation will be described. When the loading platform 4 is empty, the loading platform 4 has a pair of left and right tension springs 9.
Due to the lifting force of the loading platform of a and 9b, it is raised to the upper limit position as shown in FIGS. 1 and 2. At this time, the spring receivers 17a to 17c are in contact with the lower surface of the frame upper end horizontal frame portion 2c in a state of being fitted to the spring receiver support portions 19a to 19c of the vertical nose portion 7 of the loading platform, as shown in FIG. Each movable locking device
The locking claws 23 in the front-rear direction of 16a to 16c are loosely fitted in the through holes 29 of the spring receiving members 17a to 17c as shown in FIG.

As described above, when the locking claws 23 of all the movable locking members 16a to 16c are oriented in the front-rear direction, since these locking claws 23 are not engaged with the spring receiving members 17a to 17c, these spring receiving members are not supported. Since the tension springs 10a to 10c whose upper ends are locked to the tools 17a to 17c are not connected to the frame upper end horizontal frame portion 2c, the loading platform 4 has a pair of tension springs 9a and 9b.
Biased upwards only by. Therefore, the loading platform 4
When an article is placed on the loading section 8 of the
The loading platform 4 is lowered against the loading platform lifting force of 9a and 9b,
At the position where the load and the lifting force of the loading platform are balanced, the loading platform 4
Stops stable. When the loading platform 4 is lowered in this manner, the spring receiving members 17a to 17c are fitted to the spring receiving member supporting portions 19a to 19c of the loading platform vertical base 7 as shown by the spring receiving members 17a and 17b in FIG. In the supported state, the movable locks 16a to 16c are detached from the locking claws 23 and descend together with the loading platform 4. At this time, the brackets 18a to 18c protruding downward from the spring receivers 17a to 17c are attached to the loading platform vertical base 7
Since it is fitted between the pair of front and rear connecting plates 12a, 12b, there is no fear that the spring receivers 17a to 17c will come off from the spring receiver support brackets 19a to 19c in the front-rear direction.

When the article to be handled is heavy and the descending amount of the loading platform 4 is too large, and the upper end level of the article placed on the loading section 8 becomes too low, the pulling force acting on the loading platform 4 is increased. Therefore, the middle three extension springs 10a-10c
Are selectively involved in lifting the platform according to the weight of the article to be handled. For example, when only the central tension spring 10c is to be used for lifting the platform, the central movable locking member 16c is used when the platform 4 is at the upper limit position, and the rotation operation groove 26 shown in FIG. 6 is used. Then, as shown by the phantom line in FIG. 8, the torsion coil spring 24 is pushed down against the upward biasing force to disengage the locking claw 23 from the through hole 29 of the spring receiver 17c downward, In the direction of arrow 25 in FIG. 6 against the torsional biasing force of the torsion coil spring 24.
It is rotated by 90 degrees, and the twisted coil spring is in such a state.
The locking claw 23 is lifted by the upward biasing force of the valve 24 to engage the locking claw 23 with the locked portion 30 of the spring receiver 17c. At this time, the locking claw 23 overcomes the frictional force with the locked portion 30 of the spring receiving member 17c and twists so that the locking biasing force of the coil spring 24 does not return the original rotation in the front-back direction. The torsional biasing force of the coil spring 24 is made small, and the upward biasing force is made large. In addition, the locking claw 23
If the locking claw 23 is configured to contact the stopper 27 when rotated once, the locking claw 23 can be easily rotated by 90 degrees.

As described above, the locking claw 23 of the movable locking member 16c is engaged with the spring receiver 17c, and the upper end of the tension spring 10c is connected to the frame upper end horizontal frame portion 2 via the spring receiver 17c.
When it is connected to c, it acts so as to pull up the loading platform 4 which is lowered by the load upward by the three springs of the pair of left and right tension springs 9a and 9b and the central tension spring 10c as shown in FIG. The pulling force acting on the loading platform 4 is increased by the pulling force of the central tension spring 10c.

Further, since the articles to be handled are heavy, when the two tension springs 10b and 10c are to be involved in lifting the loading platform, or when the three tension springs 10a to 10c are to be involved in lifting the loading platform, these tension springs are used. 10a ~ 10c
The spring receivers 17a to 17c that lock the upper ends of the above can be connected to the frame upper end horizontal frame portion 2c as described above using the movable locking members 16a to 16c. On the contrary, since the articles to be handled are light in weight, when the number of the tension springs 10a to 10c participating in the lifting of the loading platform is reduced, when the loading platform 4 is at the upper limit position, the movable locking members 16a to 16c are used. Of these, the movable locking device that locks the tension spring that you want to switch to the non-operation state is pushed down to return the locking claw 23 to the original front-back direction in which it abuts the stopper 27, and the upward biasing force of the torsion coil spring 24 is applied. The locking claw 23 is returned and loosely fitted into the through hole 29 of the spring receivers 17a to 17b, and the connection between the spring receiver that locks the tension spring desired to be switched to the inactive state and the frame upper end horizontal frame portion 2c is released. Good.

In addition, the movable catches 16a-1 to the spring receivers 17a-17c
It is also possible to attach 6c and provide the through hole 29 and the locked portion 30 on the side of the upper frame horizontal frame portion 2c. Further, all tension springs 9a to 10c can be configured to be disengageable on the frame 2 side by a movable locking member.

(Operation and Effect of the Invention) As described above, according to the automatic lifting platform of the present invention, when the loading platform is at the upper limit position, the movable locking member is rotated so that the locking claw is on the spring receiving side or the frame side. By engaging with the engaged portion of the spring receiver, the tension spring retained in the spring receiver functions as a spring for lifting the loading platform, and conversely, the engaging claw is engaged on the spring receiver side or the frame side. By disengaging from the locking portion, the tension spring locked to the spring receiver can be switched to the inactive state. Therefore,
Depending on the weight of the article to be handled, the movable locking device is operated to change the number of tension springs effective for lifting the platform,
The lifting force of the loading platform can be adjusted in stages.

Moreover, according to the present invention, since it suffices to operate the movable locking member provided corresponding to each tension spring,
Stepwise adjustment of the platform lifting force can be performed very easily and quickly, and since each tension spring is directly engaged with and disengaged from the frame, the structure is relatively simple and can be implemented at low cost, and the tension spring can be used for loads. It reacts sensitively and does not cause variations in the stable position of the loading platform.

[Brief description of drawings]

FIG. 1 is a front view, FIG. 2 is a side view, FIG. 3 is a partially longitudinal front view showing the operating state of essential parts, FIG. 4 is a longitudinal side view of the same, FIG. 6 is a partial cross-sectional plan view of the movable locking member, FIG. 7 is a vertical sectional front view of the same portion, FIG. 8 is a partial vertical sectional front view showing the movable locking member and a spring receiver, and FIG. It is a cross-sectional top view which shows the state which engaged the locking tool with the spring receiving tool. 1 ... carriage, 2 ... frame, 4 ... loading platform, 5 ... longitudinal positioning roller, 6 ... horizontal lateral positioning roller, 7 ... loading platform vertical base, 8 ... loading section, 9a, 9
b, 10a to 10c ... tension spring, 16a to 16c ... movable locking member, 17a to 17c ... spring receiving member, 19a to 19c ... spring receiving member support portion, 23 ... locking claw, 24 ... Twisted coil spring, 27 ... Stopper, 29 ... Through hole, 30 ...
... Locked part.

Claims (1)

(57) [Claims] 1. A loading platform supported by a frame so as to be capable of moving up and down,
In an automatic lifting platform having a tension spring for biasing the platform in the ascending direction between the platform and the frame,
A plurality of the tension springs are arranged side by side, and at least one tension spring is engaged with a spring receiver that is removably locked to the frame by a movable locking member, and the loading platform is at an upper limit position. A spring receiving member supporting portion for supporting the spring receiving member in a fixed position is provided on the loading platform, and the movable locking member is rotatably attached to one of the frame and the loading platform, and Is an automatic lifting / lowering platform comprising a locked portion to which the locking claw of the movable locking tool can be engaged and disengaged.