CA1076388A - Penetration body for impact strength measurement of wood - Google Patents
Penetration body for impact strength measurement of woodInfo
- Publication number
- CA1076388A CA1076388A CA259,756A CA259756A CA1076388A CA 1076388 A CA1076388 A CA 1076388A CA 259756 A CA259756 A CA 259756A CA 1076388 A CA1076388 A CA 1076388A
- Authority
- CA
- Canada
- Prior art keywords
- piercing plug
- wood
- casing
- plug
- inertia body
- 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.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/40—Investigating hardness or rebound hardness
- G01N3/48—Investigating hardness or rebound hardness by performing impressions under impulsive load by indentors, e.g. falling ball
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The disclosure relates to a method for the non-destructive testing of wood to determine the impact strength thereof essentially independently of the moisture content.
The method involves driving a piercing plug having a blunt head into a body of wood substantially transverse to the grain thereof by imparting to said piercing plug a predetermined amount of kinetic energy to cause the plug to penetrate the wood and rupture fibers thereof to produce surfaces of frac-ture as a result of dynamic bending stress and dynamic tensile stress of the wood fibers, and determining the extent of pene-tration of the plug into the wood, whereby said extent of penetration is proportional to the impact strength of the wood.
The disclosure relates to a method for the non-destructive testing of wood to determine the impact strength thereof essentially independently of the moisture content.
The method involves driving a piercing plug having a blunt head into a body of wood substantially transverse to the grain thereof by imparting to said piercing plug a predetermined amount of kinetic energy to cause the plug to penetrate the wood and rupture fibers thereof to produce surfaces of frac-ture as a result of dynamic bending stress and dynamic tensile stress of the wood fibers, and determining the extent of pene-tration of the plug into the wood, whereby said extent of penetration is proportional to the impact strength of the wood.
Description
~L~763~3~
PENETRATION BODY FOR IMPACT STRENGTH ~5EASUREMENT OF WOOD.
The appllcation relates to a method of measuring the strength of a body, such as a wooden material, and an apparatus for perfor-mance of the method.
Various methods for testing the strength of a body, such as a wooden material, by mechanical stressing of the material, are known. A pointed object can be pressed into it with a constant power and the penetration be judgedr Furthermore drill samples can be taken, the compressive strength of which can be then mea-sured. These two methods, however, have proved to be too unde-pendable. Furthermore the rigidity of the material can be mea-sured, where practically feasible, by exposing the material to a given load and the strength be determined on a basis of de-flection. This method is, however, very difficult to carry out in practice.
Finally the impact strength of the material can be determined.
This method is the preferred one, as the impact strength has proved to be an indicator of the mechanical properties of the material, which i.a. depends on the degree of disintegration of the material and its density. The impact strength thus largely depends on the general condition of the material Disintegration by biological or baterial means e.g. means a marked fall of the impact strength. Furthermore the impact ,, : :. . . i. ." .,~
-. . : . :- .:
1C~7~3~38 -strength strongly depends on the density of the material. And finally the impact strength is practically independent on the contents of water of the material.
Hitherto known measurings of the impact strength have been made in laboratories on small prisms, taken from the material and placed in a special testing machine, in which the prism is exposed to a combined dynamical bending and tensile stress. This method is often inexpedient as it partly demands that one or several samples are taken, and paxtly that the measuring must be made on a machine in a laboratory. Furthermore it weakens the material and it is a costly and time-consuming method.
An object of the present invention is to provide an improved method for the non-destructive testing of wood to determine the impact strength thereof essentially independently of the moisture content. The method involves driving a piercing plug having a blunt head into a body of wood substantially transverse to the grain thereo~ by imparting to said piercing plug a predetermined amount of kinetic energy to cause the plug to penetrate the wood and rupture fibers thereof to produce surfaces of frac-ture as a result of dynamic bending stress and dynamic tensile stress of the wood fibers, and determining the extent of pene-tration of the plug into the wood, whereby said extent of penetration is proportional to the impact strength of the wood.
An advantage of the method of the invention is that the testing can be conducted in situ. Furthermore a direct determination of the impact strength of the wood immediately after the im-pact is achieved, as the penetration of the piercing plug depends on all the factors, which are of importance to the mechanical properties of the material. There is, therefore, a direct connection between the strength and the degree of penetration. As the penetration of the piercing plug can be read off directly after the driving in, is in addition achieved, that the operators can make supplementary measurings, where zones appear, which may require a further examination. Furthermore, the ' `~ Sl ' ~` .
.. ..
~ : .
- .. i: ..
-: .. : -; :, .. .
- :, . :
.. : . ... .. :,,,, , ;, : ~
- . , : . : :~.: :: : -. , .. . .
: .... ; : , .. .
', ~ , - ~76388 3 ~
material is not spoiled by this method as no samples ha~e tD be taken.
The method may be performed using an impac~ hammer, which has the advantage that the testing operation can be performed in-dependently of the operators, as the impact hammer contains a well defined kinetic ener~y, which is uniform at each impact.
The impact hammer may have a drive arrangement which is simple and steady, and may include a trigger which is operable in re-sponse to a given pressure on the impact hammer. This enables a constant pre-pressure to be achieved for the driving in be-fore the impact. This will secure uniform conditions o~ the driving in.
To be able to read off the penetration o the piercing plug into the material it is suitable to the purpose to provide the casing with an opening opposite to the inertia body and to place a scale in the opening so that the penetration depth and with that, the strength can be determined.
To facilitate the determination of the strength of e.g. a burried post the ront end of the impact hammer casing may be obliquely cut, so that testings of the strength of the post in the area immediately under the surface of the ground can be made without having first to remove laxge quantities of earth.
The invention will be explained in further details below with reference to the drawings in which:
Fig. 1 shows an impact hammer in side elevation in section;
Fig. 2 shows the impact hammex in its advanced position; and, Fig. 3 shows the impact hammer in process of being driven into a wooden material.
The apparatus for use in performance of the method can be designed as shown in Fig. 1 and 2. It consists of an impact hammer 4 which has uttermost a casing 6, which in front is provided with a front piece 9 and to the rear with a trigger arrangement. The casing 6 is suitably shaped like a cylindrical pipe, into which the impact ~ . .
.
. .
; : .
6~38 arrangement can be built in. This impact arrangement consists of an inertia body 5 which in front is provided with a re-tainin~ member, to which a penetration body or piercing plug
PENETRATION BODY FOR IMPACT STRENGTH ~5EASUREMENT OF WOOD.
The appllcation relates to a method of measuring the strength of a body, such as a wooden material, and an apparatus for perfor-mance of the method.
Various methods for testing the strength of a body, such as a wooden material, by mechanical stressing of the material, are known. A pointed object can be pressed into it with a constant power and the penetration be judgedr Furthermore drill samples can be taken, the compressive strength of which can be then mea-sured. These two methods, however, have proved to be too unde-pendable. Furthermore the rigidity of the material can be mea-sured, where practically feasible, by exposing the material to a given load and the strength be determined on a basis of de-flection. This method is, however, very difficult to carry out in practice.
Finally the impact strength of the material can be determined.
This method is the preferred one, as the impact strength has proved to be an indicator of the mechanical properties of the material, which i.a. depends on the degree of disintegration of the material and its density. The impact strength thus largely depends on the general condition of the material Disintegration by biological or baterial means e.g. means a marked fall of the impact strength. Furthermore the impact ,, : :. . . i. ." .,~
-. . : . :- .:
1C~7~3~38 -strength strongly depends on the density of the material. And finally the impact strength is practically independent on the contents of water of the material.
Hitherto known measurings of the impact strength have been made in laboratories on small prisms, taken from the material and placed in a special testing machine, in which the prism is exposed to a combined dynamical bending and tensile stress. This method is often inexpedient as it partly demands that one or several samples are taken, and paxtly that the measuring must be made on a machine in a laboratory. Furthermore it weakens the material and it is a costly and time-consuming method.
An object of the present invention is to provide an improved method for the non-destructive testing of wood to determine the impact strength thereof essentially independently of the moisture content. The method involves driving a piercing plug having a blunt head into a body of wood substantially transverse to the grain thereo~ by imparting to said piercing plug a predetermined amount of kinetic energy to cause the plug to penetrate the wood and rupture fibers thereof to produce surfaces of frac-ture as a result of dynamic bending stress and dynamic tensile stress of the wood fibers, and determining the extent of pene-tration of the plug into the wood, whereby said extent of penetration is proportional to the impact strength of the wood.
An advantage of the method of the invention is that the testing can be conducted in situ. Furthermore a direct determination of the impact strength of the wood immediately after the im-pact is achieved, as the penetration of the piercing plug depends on all the factors, which are of importance to the mechanical properties of the material. There is, therefore, a direct connection between the strength and the degree of penetration. As the penetration of the piercing plug can be read off directly after the driving in, is in addition achieved, that the operators can make supplementary measurings, where zones appear, which may require a further examination. Furthermore, the ' `~ Sl ' ~` .
.. ..
~ : .
- .. i: ..
-: .. : -; :, .. .
- :, . :
.. : . ... .. :,,,, , ;, : ~
- . , : . : :~.: :: : -. , .. . .
: .... ; : , .. .
', ~ , - ~76388 3 ~
material is not spoiled by this method as no samples ha~e tD be taken.
The method may be performed using an impac~ hammer, which has the advantage that the testing operation can be performed in-dependently of the operators, as the impact hammer contains a well defined kinetic ener~y, which is uniform at each impact.
The impact hammer may have a drive arrangement which is simple and steady, and may include a trigger which is operable in re-sponse to a given pressure on the impact hammer. This enables a constant pre-pressure to be achieved for the driving in be-fore the impact. This will secure uniform conditions o~ the driving in.
To be able to read off the penetration o the piercing plug into the material it is suitable to the purpose to provide the casing with an opening opposite to the inertia body and to place a scale in the opening so that the penetration depth and with that, the strength can be determined.
To facilitate the determination of the strength of e.g. a burried post the ront end of the impact hammer casing may be obliquely cut, so that testings of the strength of the post in the area immediately under the surface of the ground can be made without having first to remove laxge quantities of earth.
The invention will be explained in further details below with reference to the drawings in which:
Fig. 1 shows an impact hammer in side elevation in section;
Fig. 2 shows the impact hammex in its advanced position; and, Fig. 3 shows the impact hammer in process of being driven into a wooden material.
The apparatus for use in performance of the method can be designed as shown in Fig. 1 and 2. It consists of an impact hammer 4 which has uttermost a casing 6, which in front is provided with a front piece 9 and to the rear with a trigger arrangement. The casing 6 is suitably shaped like a cylindrical pipe, into which the impact ~ . .
.
. .
; : .
6~38 arrangement can be built in. This impact arrangement consists of an inertia body 5 which in front is provided with a re-tainin~ member, to which a penetration body or piercing plug
2 can be attached. The forward motion of the inertia body 5 causes that the piercing plug 2 is led out through an open-ing in the front piece 9, max. until the retaining member rests against the inner side of the front piece, as shown in fig. 2.
To the front of the inertia body 5 is attached a tension spring 7, the opposite end of which is attached to the front end of the casing at the front piece 9. In the compressed position of the spring 7, i.e. in its relaxed position, as shown in fig. 2, the piercing plug 2 is most advanced. By ca~rying the inertia body 5 back into the casing 6, the spring 7 is loaded. In order to keep the impact arrangement in its loaded position, as shown in fig. 1, the inertia body is at the back provided with a retainer pin 16, with a head, which can be caught by a rocker arm 15 at its one end. The rocker arm 15, which turns round a pin in the casing, is spring loaded for introduction into the path of the retainer pin by means of a compression spring 14 which loads the other end of the arm so that the inertia body 5 is kept by the rocker arm 15.
Release of the impact hammer takes place by compressive stress of the rocker arm 15 against the spring 14. This stress takes place on a trigger part 13 forming the rear end of the tool 4. This trigger part is mounted axially dis-placeable in the casing 6 against the power of one Or several compression springs 17. When the part 13 is pressed in-wardly, the spring power from the springs 17 and 14 must be overcome before the rocker arm 15 swings out of its mesh with the pin 16 thereby releasing the inertia body which is driven forward by the spring 7 and thereby leads the piercing plug 2 out of the casing 6.
The piercing plug 2 is in the shown example a cylindrical body with a blunt front end 3, as shown in fig. 2. During its penetration surfaces of fracture are produced in the .
... . ; . ':', , -, ,; :
~L~763~3~
material, for which reason the size of the piercing plug and the shape of the front end can be found out by way of experi-ments, dependent on the use of the tool.
The casing is provided with an opening 8, as shown in fig. 1.
This opening is located in such a n~anner that the penetra-tion of the ~iercing plug into the material can be read off.
The opening can suitably be provided with a scale lo, which scale can be replaceable dependent on the use of the tool and the nature of the material.
The retaining member can be stopped at the front end 9 of the tool, by means of an insertable pin 12, which can be manually inserted into the member. Hereby it is partly prevented from turning itself by replacement of the piercing plug by turning of the bushing which keeps the piercing plug 2 and partly to keep the member in the advanced position when using the tool as a awllike tool for informatory testing of the nature of the surface of the material when inserting the piercing plug into the material.
The front end 9 has been obliquely cut for formation of an oblique contact face 11. Two opposite oblique contact faces 11 have been shown and on the parts of the front end 9 having not been cut, one or several pins have been mounted, as can be seen in fig. 2. These pins facilitate the inser-tion work, as they can get into the material and keep it during the triggering. If it is desired to drive in, in an inclined direction, i.e. not at right angles to the surface of the material, the contact faces are used for guiding the tool. This is particularly suitable to the purpose when exàmining buried piles, as hereby is avoided to have to re-move unnecessarily large quanties of earth.
To describe the method reference is made below to fig. 3, which shows the tool in use. The trigger is loaded by a manual pressure under overcoming of the said spring powers.
This spring load is of a definite size in order to secure that the front end 9 of the tool possesses a f inely tuned starting pressure against the material 1. This is a ` ~ : ', ~ ', ' ;
.
~763~
condition for comparability of the readings. It ensures that the piercin~ plug is always released at the correct point of time, viz. when the spring load has been overcome. During the penetration of the piercing plug into the material sur-faces of fracture are produced in the material dependent on its condition and nature. As the degree of penetration depends on all the factors being of importance to the mechanical properties of the material the penetration is, therefore, a measure of the strength of the material. This strength can be read off directly after the impact, by observing the position of the inertia body through the open-ing 8 in the tool. In determining now the proportion by a given penetration and the strength of a body by way of experi-ment and mark it out on the scale, the tool can be used as a strength measurer.
The strength of a material, e.g. a wooden material can be stressed by many sorts of disintegration. It is consequently extraordinarily important, that people in situ and immediately after the driving in can determine whether the material possesses the necessary strength. This applies to wiring work in wooden masts, foundations, pile structures, etc. These measurings can be made by people without any special qualifi-cations, and as the material is not interfered with, which could possibly weaken it, the determination of the strength is enormously suitable to the purpose.
~.- - , ' ~
. .. .
. ~
To the front of the inertia body 5 is attached a tension spring 7, the opposite end of which is attached to the front end of the casing at the front piece 9. In the compressed position of the spring 7, i.e. in its relaxed position, as shown in fig. 2, the piercing plug 2 is most advanced. By ca~rying the inertia body 5 back into the casing 6, the spring 7 is loaded. In order to keep the impact arrangement in its loaded position, as shown in fig. 1, the inertia body is at the back provided with a retainer pin 16, with a head, which can be caught by a rocker arm 15 at its one end. The rocker arm 15, which turns round a pin in the casing, is spring loaded for introduction into the path of the retainer pin by means of a compression spring 14 which loads the other end of the arm so that the inertia body 5 is kept by the rocker arm 15.
Release of the impact hammer takes place by compressive stress of the rocker arm 15 against the spring 14. This stress takes place on a trigger part 13 forming the rear end of the tool 4. This trigger part is mounted axially dis-placeable in the casing 6 against the power of one Or several compression springs 17. When the part 13 is pressed in-wardly, the spring power from the springs 17 and 14 must be overcome before the rocker arm 15 swings out of its mesh with the pin 16 thereby releasing the inertia body which is driven forward by the spring 7 and thereby leads the piercing plug 2 out of the casing 6.
The piercing plug 2 is in the shown example a cylindrical body with a blunt front end 3, as shown in fig. 2. During its penetration surfaces of fracture are produced in the .
... . ; . ':', , -, ,; :
~L~763~3~
material, for which reason the size of the piercing plug and the shape of the front end can be found out by way of experi-ments, dependent on the use of the tool.
The casing is provided with an opening 8, as shown in fig. 1.
This opening is located in such a n~anner that the penetra-tion of the ~iercing plug into the material can be read off.
The opening can suitably be provided with a scale lo, which scale can be replaceable dependent on the use of the tool and the nature of the material.
The retaining member can be stopped at the front end 9 of the tool, by means of an insertable pin 12, which can be manually inserted into the member. Hereby it is partly prevented from turning itself by replacement of the piercing plug by turning of the bushing which keeps the piercing plug 2 and partly to keep the member in the advanced position when using the tool as a awllike tool for informatory testing of the nature of the surface of the material when inserting the piercing plug into the material.
The front end 9 has been obliquely cut for formation of an oblique contact face 11. Two opposite oblique contact faces 11 have been shown and on the parts of the front end 9 having not been cut, one or several pins have been mounted, as can be seen in fig. 2. These pins facilitate the inser-tion work, as they can get into the material and keep it during the triggering. If it is desired to drive in, in an inclined direction, i.e. not at right angles to the surface of the material, the contact faces are used for guiding the tool. This is particularly suitable to the purpose when exàmining buried piles, as hereby is avoided to have to re-move unnecessarily large quanties of earth.
To describe the method reference is made below to fig. 3, which shows the tool in use. The trigger is loaded by a manual pressure under overcoming of the said spring powers.
This spring load is of a definite size in order to secure that the front end 9 of the tool possesses a f inely tuned starting pressure against the material 1. This is a ` ~ : ', ~ ', ' ;
.
~763~
condition for comparability of the readings. It ensures that the piercin~ plug is always released at the correct point of time, viz. when the spring load has been overcome. During the penetration of the piercing plug into the material sur-faces of fracture are produced in the material dependent on its condition and nature. As the degree of penetration depends on all the factors being of importance to the mechanical properties of the material the penetration is, therefore, a measure of the strength of the material. This strength can be read off directly after the impact, by observing the position of the inertia body through the open-ing 8 in the tool. In determining now the proportion by a given penetration and the strength of a body by way of experi-ment and mark it out on the scale, the tool can be used as a strength measurer.
The strength of a material, e.g. a wooden material can be stressed by many sorts of disintegration. It is consequently extraordinarily important, that people in situ and immediately after the driving in can determine whether the material possesses the necessary strength. This applies to wiring work in wooden masts, foundations, pile structures, etc. These measurings can be made by people without any special qualifi-cations, and as the material is not interfered with, which could possibly weaken it, the determination of the strength is enormously suitable to the purpose.
~.- - , ' ~
. .. .
. ~
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for the non-destructive testing of wood to determine the impact strength thereof essentially independently of the moisture content, comprising driving a piercing plug having a blunt head into a body of wood substantially trans-verse to the grain thereof by imparting to said piercing plug a predetermined amount of kinetic energy to cause said piercing plug to penetrate said wood and rupture fibers thereof to produce surfaces of fracture as a result of dynamic bending stress and dynamic tensile stress of the wood fibers, and determining the extent of penetration of said piercing plug into said wood, whereby said extent of penetration is propor-tional to the impact strength of said wood.
2. A method as claimed in claim 1, wherein the piercing plug forms part of an impact hammer.
3. An apparatus for performing the method claim in claim 1, comprising an impact hammer including a casing, an inertia body movable linearly in said casing, a piercing plug having a blunt head and coupled to said inertia body for movement between a first position in which said piercing plug projects from said casing, and a second position in which said piercing plug is disposed within the casing and a spring disposed in said casing for co-operation with said inertia body and arranged so as to be stressed by said inertia body when the piercing plug is in its said second position and to bring the piercing plug to its first position upon release of said inertia body, whereby the spring provides said kinetic energy for the piercing plug.
4. An apparatus as claimed in claim 3, further comprising a releasable trigger adapted to co-operate with said inertia body for maintaining said piercing plug in its said first position, and spring means biassing said trigger to co-operate with said plug.
5. An apparatus as claimed in claim 3, wherein said casing is provided with an opening through which the position of the inertia body with respect to the casing can be visually determined as an indication of the extent of penetration of the piercing plug into a material in use.
6. An apparatus as claimed in claim 5, wherein said opening is provided with a measuring scale.
7. An apparatus as claimed in claim 3, wherein said casing has a front end through which said piercing plug ex-tends in its said first position, said front end of the casing including an oblique contact face which can be positioned against a material the strength of which is to be tested, and by which the hammer is positioned to permit driving of the piercing plug obliquely into said material.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DK394375A DK138862B (en) | 1975-09-03 | 1975-09-03 | Method and apparatus for measuring the strength of a body, in particular a wooden blank. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1076388A true CA1076388A (en) | 1980-04-29 |
Family
ID=8128521
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA259,756A Expired CA1076388A (en) | 1975-09-03 | 1976-08-24 | Penetration body for impact strength measurement of wood |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS5917778B2 (en) |
| CA (1) | CA1076388A (en) |
| DE (1) | DE2638261A1 (en) |
| DK (1) | DK138862B (en) |
| ES (1) | ES451200A1 (en) |
| FR (1) | FR2323140A1 (en) |
| GB (1) | GB1553311A (en) |
| SE (1) | SE420132B (en) |
| SU (1) | SU847946A3 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4343179A (en) * | 1979-11-27 | 1982-08-10 | Astroem Goeta L | Utility pole hardness tester |
| DE3501841C2 (en) * | 1985-01-22 | 1994-04-14 | Kamm Willibald F G Dipl Ing | Method and device for determining the internal condition of trees or wooden components |
| JPS61186541A (en) * | 1985-02-08 | 1986-08-20 | 村田機械株式会社 | Spun yarn |
| JPS63192476U (en) * | 1987-05-28 | 1988-12-12 | ||
| US5099682A (en) * | 1990-03-12 | 1992-03-31 | Denomme Catherine E | Meat doneness tester |
| FR2707759B1 (en) * | 1993-07-13 | 1995-09-01 | Sandoz Jean Luc | Method and apparatus for monitoring the state of deterioration of wooden structures, in particular posts. |
| EP0738703B1 (en) * | 1995-02-28 | 2002-05-22 | Nippon Shokubai Co., Ltd. | Acrylic acid derivatives, method for preparing the acrylic acid derivatives, and acrylic acid polymers |
| RU2250449C2 (en) * | 2003-06-16 | 2005-04-20 | Томский политехнический университет | Method of strength testing of hard materials |
| JP2010271112A (en) * | 2009-05-20 | 2010-12-02 | Yoshihisa Fujii | Method for evaluating strength of wood and woody material |
| US8210024B2 (en) * | 2009-10-16 | 2012-07-03 | The Boeing Company | Damage impactor |
| DE102011018971A1 (en) * | 2011-04-28 | 2012-10-31 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Device for determining transverse tensile strength of timber material product e.g. oriented strand board-plate, has energy storage loading penetrator with force, and display device displaying penetration depth of penetrator into product |
| DE102011107899A1 (en) * | 2011-07-18 | 2013-01-24 | Carl Scholl Gmbh | Method for classification of round timber with wood moisture measuring device for masts, particularly for line construction, involves introducing pin, particularly metal pin with predetermined penetration depth into round timber |
| ES2606331B2 (en) * | 2016-11-15 | 2017-07-25 | Universidad Politécnica de Madrid | Portable machine and procedure to perform soft impact tests, with large load application area, on fragile materials |
| CN113624589B (en) * | 2021-08-16 | 2022-05-17 | 沭阳县润丰木业制品厂 | An intelligent wood measuring bracket |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1708262A (en) * | 1927-02-25 | 1929-04-09 | Executor Lou Bradshaw | Hardness-testing device |
| GB1092038A (en) * | 1965-05-05 | 1967-11-22 | Zavoid Za Str Konstrukzii | Improved non-destructive hardness testing device |
| US3421364A (en) * | 1965-08-04 | 1969-01-14 | Gkn Group Services Ltd | Methods of and apparatus for measuring the hardness of materials |
-
1975
- 1975-09-03 DK DK394375A patent/DK138862B/en not_active IP Right Cessation
-
1976
- 1976-08-24 CA CA259,756A patent/CA1076388A/en not_active Expired
- 1976-08-25 DE DE19762638261 patent/DE2638261A1/en active Granted
- 1976-08-31 GB GB3604076A patent/GB1553311A/en not_active Expired
- 1976-09-02 JP JP10434176A patent/JPS5917778B2/en not_active Expired
- 1976-09-02 SE SE7609692A patent/SE420132B/en not_active IP Right Cessation
- 1976-09-03 ES ES451200A patent/ES451200A1/en not_active Expired
- 1976-09-03 SU SU762396658A patent/SU847946A3/en active
- 1976-09-03 FR FR7626580A patent/FR2323140A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| FR2323140B1 (en) | 1982-11-19 |
| DE2638261A1 (en) | 1977-03-10 |
| SE420132B (en) | 1981-09-14 |
| ES451200A1 (en) | 1977-09-16 |
| DK394375A (en) | 1977-03-04 |
| DK138862C (en) | 1979-04-23 |
| JPS5917778B2 (en) | 1984-04-23 |
| SU847946A3 (en) | 1981-07-15 |
| GB1553311A (en) | 1979-09-26 |
| SE7609692L (en) | 1977-03-04 |
| JPS5230489A (en) | 1977-03-08 |
| FR2323140A1 (en) | 1977-04-01 |
| DK138862B (en) | 1978-11-06 |
| DE2638261C2 (en) | 1987-09-03 |
Similar Documents
| Publication | Publication Date | Title |
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