Patent Application
20240426993
The present invention relates to the field of distance measuring tools, and in particular to a distance measuring device that employs tape and laser measurement.
Tapelines and laser ranging devices are common distance measuring tools. They have found applications in the fields of building construction, interior decoration, traffic accident disposition, and the like. In the prior art, when a tapeline is in used, the tape end part and the measuring terminal end of the tape need to be respectively level with the starting end and the terminal end of the object to be measured. The person making the measurement needs to use his/her hands or other auxiliary equipment to keep the tape on the object to be measured. In certain cases, an ordinary tapeline is inconvenient to operate and has lower measurement accuracy. For example, in the field of measurement at hazardous locations, the practicality of the ordinary tapeline is relatively poor.
In the field of building constructions, the tapeline is often used to measure the lateral length of an object at a high altitude or the vertical distance of an object above a ground reference point. Since there is no attachment point for the tapeline, the measurement can only rely on visual estimation at a distance of the start point or the terminal point to be measured. Therefore, the error of the measured value may be large and the measurement accuracy may be poor, which will adversely affect the construction work based on the measurement. If more accurate high altitude measurement data are desired beyond that which can be accomplished by using a tapeline, the measurer needs to build a supporting frame or climb high up using a ladder, so as to attach the tapeline to the object to be measured, in order to complete the measurement. If the object to be measured is very long, more than two workers are needed to climb high up to complete the measurement, which is operationally cumbersome and has a high labor costs while it is dangerous due to the risk of the measurement tool or workman falling from a great height.
In addition, due to the limit of the length of the tapeline, the applications in which it can be used are limited, so the measurement range is relatively limited to places having small spaces rather than large spaces. The ordinary tapeline usually has a measurement range of 5 meters, 7.5 meters or 10 meters. Some specially made tapelines may have a measurement range of up to 15 meters or 20 meters. However, the larger the measurement range of the tapeline, the larger the volume of the tapeline. Thus, long length tapelines are inconvenient for the workman to carry or use.
Although the laser ranging device of the prior art has higher measurement accuracy than a tapeline, it also has a larger volume and higher cost, and is inconvenient to carry and use. After being used over a long period, the light-emitting surface of the laser light source and the light-receiving surface of the light-sensitive device will experience relatively large abrasion, thereby affecting light ray feedback sensitivity and distance measuring accuracy. Moreover, the laser ranging device has larger errors in short-distance measurements, which greatly limits its use in some fields such as interior decoration. Further, it difficult to use in large-scale applications.
A potential solution to these problems is proposed in U.S. Pat. No. 11,143,494 which discloses a distance measuring device that combines a tapeline measurement device and a laser measuring device in a single case. The case is comprised of a first housing and a second housing with a third housing arranged between the first housing and the second housing. The third housing and the second housing together from a tapeline cavity where the edges of the third housing surround part of the cavity and extend into the second housing completely around the cavity. A measuring tape is provided inside the tapeline cavity.
A laser ranging device is arranged between the first housing and the third housing. The opposite side of the bottom wall of the third housing covers a further cavity were a laser ranging device is located. The laser ranging device includes a laser generating means for emitting measurement light beams to an object to be measured. At the object the light beams are reflected by the object so as to generate reflective light rays. A photoelectric conversion means captures all or part of the reflective light rays and converts them in to at least one feedback electric signal. A circuit board with a processor is connected to the laser generating means and the photoelectric conversion means. The processor acquires the feedback electric signal and calculates the distance from the object to be measured to the distance measuring device based on the time from when the light beam was sent to the object and when the reflected beam was received back from the object.
The third housing of U.S. Pat. No. 11,143,494 is difficult to manufacture because of its side walls that completely surround the tapeline cavity and extend into the second housing. Also, being one piece, it makes assembly of the device complicated. In particular, both the tapeline wheel and the laser ranging devices, which sit in the first and second housing, have to be completely assembled before the third housing can be installed between the other two housing and all three are fastened together.
According to the present invention a laser tape measurement device has both a tape measure in at tapeline cavity and a laser measuring device in an adjacent cavity. Thus, it is somewhat like that described in U.S. Pat. No. 11,143,494. However, unlike that design, it does not have a third housing with end walls that surround all of the tapeline cavity and also form part of an enclosure for the laser measuring device. In order to surround part of the tapeline cavity the third housing of the prior art is required to have side walls that are perpendicular to a vertical wall or bottom face. These side walls are received within the second housing in order to completely surround the tapeline cavity in conjunction with the second housing
The laser tape measurement device of the present invention has left and right housings or shells. The interior of the device is divided into a laser ranging device on one side and a tapeline structure located in a cavity on the other side. A tapeline wheel with measuring tape wrapped about it is located in the tapeline cavity. A lower plate covers approximately the bottom third of the tapeline cavity. It has a side wall that extend only into and is fasten to the lower part of the right housing. There is an upper plate which has no end walls extending to the right housing. Instead, it has a flat surface facing the tapeline cavity and covering two-thirds of its height. The other side of the upper housing is fastened to the left housing which contains the laser ranging device.
Thus the present invention uses lower and upper housings instead of a single third housing. These housings are much similar in design than the prior third housing and thus are easier to mold. Further, because they attach to the tapeline and laser ranging portions respectively, the device is earlier to assemble.
The foregoing and other objects and advantages of the present invention will become more apparent when considered in connection with the following detailed description and appended drawings in which like designations denote like elements in the various views, and wherein:
As shown in
The first housing 11 includes a first housing bottom face 111 (
Within the casing 1 there is an upper interior plate 13A and a lower interior plate 13B that divide the interior into the laser ranging device 2 and the tapeline structure 3 as shown in
The device of the present invention may further include a sheath 4 which can be made of elastic material or soft material, partially or fully covering the first housing side wall 112 and the second housing side wall 122, and/or partially or fully covering the joint between the first housing bottom face 111 and the first housing side wall 112. The sheath 4 serves to enhance the feel of the device in the hand of the user, increasing the friction coefficient between the device and the user's hand, which helps to prevent the device from sliding out of the user's hand. Further, if the device slides out of the user's hand, the sheath has a certain cushioning effect, and increases the potential protection of the internal electronic devices and mechanical structures from breakage.
As shown in
When the tape 32 is pulled out of the housing 1, the press block 34 presses against the tape 32 due to an attached spring force, such that the length of the tape 32 outside the casing 1 is held constant against being drawn back into the casing by the spring force on the wheel 31 seeking to wind up the tape. While the tape remains stationary due to the press block it can be read by the user. When the tape retraction button 40 is pressed, the press block is lifted from the tape and it is wound back onto the wheel to restore it to its original position.
As is typical, and as explained in more detail in U.S. Pat. No. 11,143,404, which is incorporated herein by reference in its entirety, the laser ranging device 2 includes a laser beam generator, a photodetector, a circuit board 23 with a processor, a display means 24 and a power supply in the form of batteries 26. The laser beam generator and the photodetector can be arranged side by side, or one above the other, and they are integrally combined. In one embodiment the laser generator and photodetector are arranged next to each other and are both recessed in the first housing side wall 112.
The processor on circuit board 23 is connected to the laser generator and the photodetector, which acquires the feedback electrical signal. The processor uses the feedback signal from the photodetector to calculate the distance from an object to be measured to the distance measuring device. In particular, during operation, the processor issues a control signal to command the laser beam generator to emit laser beams toward the object to be measured. The measurement light beams are reflected from the surface of the object to be measured and generate reflective light rays. At least the reflected light rays parallel with the measurement light beams are captured by the photodetector and are converted into the electrical feedback signal that is provided to the processer. The processor has a timer to record a time point when the laser generator emits laser beams due to the user operating button 42 and a time point when the feedback electric signal is obtained. Based on the time difference between the two time points, the distance from the object to be measured to the distance measuring device can be calculated. During this period of time, the laser beam goes back and forth between the object to be measured and the distance measuring device at the light velocity. Half of the product of the time difference and the light velocity is the distance to be measured between the object to be measured and the distance measuring device.
As shown in
The above are only specific implementations of the invention and are not intended to limit the scope of protection of the invention. Any modifications or substitutes apparent to those skilled in the art shall fall within the scope of protection of the invention. Therefore, the protected scope of the invention shall be subject to the scope of protection of the claims.
While the invention is explained in relation to certain embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.
